obridko

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Author name code: obridko
ADS astronomy entries on 2022-09-14
author:"Obridko, Vladimir N."

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Title: Solar and stellar activity cycles - no synchronization with
exoplanets
Authors: Obridko, V. N.; Katsova, M. M.; Sokoloff, D. D.
2022MNRAS.516.1251O Altcode: 2022arXiv220806190O; 2022MNRAS.tmp.2179O
Cyclic activity on the Sun and stars is primarily explained by
the generation of the magnetic field by a dynamo mechanism, which
converts the energy of the poloidal field into the energy of the
toroidal component due to differential rotation . There is, however,
an alternative point of view, which explains the field generation
by the gravitational influence of the planetary system and, first
of all, Jupiter. This hypothesis can be verified by comparing the
characteristics of exoplanets with the activity variations on their
associated stars. We have performed such a comparison and have drawn
a negative conclusion. No relationship between the gravitational
influence of the exoplanets and cycle of the host star could be found
in any of the cases considered. Moreover, there are reasons to believe
that a strong gravitational influence may completely eliminate cyclic
variation in stellar activity.

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Title: Solar and Stellar Flares: Frequency, Active Regions, and
Stellar Dynamo
Authors: Katsova, M. M.; Obridko, V. N.; Sokoloff, D. D.; Livshits,
I. M.
2022ApJ...936...49K Altcode: 2022arXiv220803994K
We demonstrate that for weak flares the dependence of their frequency
occurrence on spottedness can be rather weak. The fact is that
such flares can occur in both small and large active regions. At
the same time, powerful large flares of classes M and X occur much
more often in large active regions. In energy estimates, the mean
magnetic field in starspots can also be assumed to be equal to the
mean field in the sunspot umbra. So the effective mean magnetic field
is 900 Mx cm-2 in sunspots and 2000 Mx cm-2 in
starspots. Moreover, the height of the energy storage cannot be strictly
proportional to A 1/2. For stars, the fitting factor is
an order of magnitude smaller. The analysis of the occurrence rate of
powerful solar X-ray flares of class M and X and superflares on stars
shows that, with allowance for the difference in the spottedness and
compactness of active regions, both sets can be described by a single
model. Thus, the problem of superflares on stars and their absence on
the Sun is reduced to the problem of the difference in the effectiveness
of the dynamo mechanisms.

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Title: Clarifying physical properties of magnetic fields in sunspots
Authors: Obridko, Vladimir; Sokoloff, Dmitry; Livshits, Ilya; Shelting,
Bertha; Katsova, Maria
2022cosp...44.1133O Altcode:
From the very beginning and long afterwards, the number and area of
sunspots were determined visually from solar images based on their
photometric properties. Nowadays, we are using photo and numerical
records. There is no doubt, however, that the main factor determining
the very existence of a sunspot is the magnetic field. Nevertheless,
a definition of the sunspot boundary in terms of the magnetic field
is still absent in scientific literature. Here, we suggest such
a definition based on SDO/HMI observations. We demonstrate that the
radial magnetic field component at the outer boundary of the penumbra
is about 550 Mx/cm2 independent of the sunspot area and the maximum
magnetic field in the umbra. The mean magnetic field intensity in
sunspots grows slightly as the sunspot area increases up to 500-1000
m.v.h. and may reach about 900 Mx/cm2 . The mean field in umbrae
is around 2000 Mx/cm2 The total magnetic flux weakly depends on
the maximum field strength in a sunspot and is determined by the
spottedness, i.e., the sunspot number and the total sunspot area;
however, the relation between the total flux and the sunspot area is
substantially nonlinear. We suggest an explicit parametrization for
this relation. The contribution of the magnetic flux associated with
sunspots to the total magnetic flux is small, not achieving more than
20% even at the maximum of the solar activity. Acknowledgements VNO,
MMK, DDS acknowledge the support of Ministry of Science and Higher
Education of the Russian Federation under the grant 075-15-2020-780.

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Title: Automated detection of solar magnetic tornadoes based on
computer vision methods
Authors: Vorobev, Dmitrii; Obridko, Vladimir; Khabarova, Olga;
Blumenau, Mark; Fridman, Mikhail
2022cosp...44.1135V Altcode:
We show a possibility of automated detection of solar magnetic
tornadoes, using the classic computer vision and deep learning
methods. We define magnetic tornadoes, independently of their origin,
as magneto-plasma objects in the solar corona in which a magnetic field
is twisted. Typically, a whole magnetic tornado rotates resembling
tornadoes in the terrestrial atmosphere. Meanwhile, there are also
tornadoes in which only plasma flows upward along the magnetic field
spiral but the whole structure just shakes. The lack of identified
structures is one of many problems that prevent studying the physics
of magnetic tornadoes and the processes associated with them. In
particular, the filamentary rotating structures are well detectable
only at the limb, while one can only make suppositions about their
presence at the solar disk. Our method relies on analyzing SDO/AIA
images at wavelengths 171 \AA, 193 \AA, 211 \AA, 304 \AA, to which
several different algorithms are applied, namely, convolutional
and recurrent neural networks and optical flow calculations. The
new technique combines several approaches that are established in
various fields of data analysis. Such an approach allows detecting the
structures with sufficient accuracy and recall. For training objects,
we used magnetic tornadoes previously described in the literature [e.g.,
Wedemeyer et al. 2013, ApJ; Mghebrishvili et al. 2015 ApJ] as well as
newfound ones. Our method made it possible to detect those structures,
as well as to reveal previously unknown magnetic tornadoes.

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Title: What determines the number of current sheets at 1 AU?
Authors: Sagitov, Timofey; Obridko, Vladimir; Khabarova, Olga;
Kislov, Roman
2022cosp...44.1507S Altcode:
A statistical analysis of the multi-year database of current
sheets identified at 1 au. (csdb.izmiran.ru) shows that the
number of current sheets per unit of time varies by tens or even
hundreds of times. Current sheets are more often recorded during the
arrival of turbulent plasma flows associated with ICME sheaths and
corotating/stream interaction regions (CIRs/SIRs). We have previously
found that the number of current sheets per day is determined by the sum
of densities of the kinetic energy and the thermal energy of the solar
wind (Khabarova et al. 2021). This fact raises the following question:
Do the current sheets heat the plasma around them or an increase in the
current sheet number is caused by an increase in the temperature? With
both theories having ardent supporters, we provide additional facts
for consideration in this debate, analysing statistical properties of
current sheets. We compare the number of identified current sheets per
day with the effective multipole index (Obridko et al, 2021), the number
of sunspots and the solar wind temperature. We show that long-term
variations in the current sheet rate have a solar origin, while
short-term variations come from local processes in the solar wind. We
underline the fact that a good correlation between the occurrence
of current sheets and the increased temperature does not prove the
fact of heating of the solar wind by current sheets. Khabarova, O.,
Sagitov, T., Kislov, R., &amp; Li, G. Automated identification of
current sheets—A new tool to study turbulence and intermittency
in the solar wind. Journal of Geophysical Research: Space Physics,
126, e2020JA029099. (2021). https://doi.org/10.1029/2020JA029099
Obridko, V.N., Sokoloff, D. D., Pipin, V.V., Shibalva, A. S., Livshits,
I. M. Zonal harmonics of solar magnetic field for solar cycle forecast,
Journal of Atmospheric and Solar-Terrestrial Physics, 2021, 225,
105743, DOI: https://doi.org/10.1016/j.jastp.2021.105743

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Title: Solar and stellar flares: occurrence frequency, properties
of active regions and efficiency of stellar dynamo
Authors: Obridko, Vladimir; Sokoloff, Dmitry; Livshits, Ilya;
Katsova, Maria
2022cosp...44.1138O Altcode:
It was demonstrated that for weak flares the dependence on spottedness
can be rather weak. The fact is that such flares can occur both in
small and large active regions. At the same time, powerful large flares
of classes M and X occur much more often in large active regions. It
should be noted that the procedures used to determine the spot areas
on the Sun and stars are essentially different. In the former case,
the observer directly calculates the area of each spot from the full
image of the Sun and, then, sums up the values obtained. The penumbra
is traditionally included in the spot area. For stars, a different
procedure is used, which is based on the temperature difference between
the star and the observed spot. This difference corresponds to the
temperature difference between the spot umbra and the star. This means
that, in fact, we find the total area of the umbra or, to be more
precise, the area of a starspot can be considered coinciding with the
area of the umbra. Therefore, in energy estimates, the mean magnetic
field in starspots can also be assumed equal to the mean field in the
sunspot umbra. So the effective mean magnetic field is ~900 Mx/cm^2 in
sunspots and ~2000 Mx/cm^2 in starspots. K Moreover, the height of the
energy storage cannot be strictly proportional to A^1/2. For stars,
the fitting factor is an order of magnitude smaller. The analysis of
the occurrence rate of powerful solar X-ray flares of class M and X
and superflares on stars shows that, with allowance for the difference
in the spottedness and compactness of active regions, both sets can be
described by a single model. Thus, the problem of superflares on stars
and their absence on the Sun is reduced to the problem of difference in
the effectiveness of the dynamo mechanisms. Acknowledgements Authors
acknowledge the support of Ministry of Science and Higher Education
of the Russian Federation under the grant 075-15-2020-780.

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Title: A non-linear approach to predicting the amplitude and timing
of the sunspot area in cycle 25
Authors: Chowdhury, Partha; Sarp, Volkan; Kilcik, Ali; Ray, Pratap
Chandra; Rozelot, Jean-Pierre; Obridko, Vladimir N.
2022MNRAS.513.4152C Altcode:
The sunspot cycle waxes and wanes over a period of about 11 years and
modulates 'space weather'. Therefore, predicting the maximum amplitude
of the solar cycle is an important goal for both solar physics and space
weather. It is clear nowadays that cyclic variations of the Sun are
non-linear processes, and thus the above-mentioned goal is difficult
to reach with accuracy, albeit several methods currently exist to
forecast both long-term and short-term variations. Solar cycle 25
has recently started and knowing the strength and timing of maximum
of this cycle in advance is essential. In this study, a non-linear
prediction algorithm, non-linear empirical dynamical modelling (EDM),
is used to forecast the maximum amplitude and timing of the sunspot
area of this cycle. This technique was tested on the last solar cycle
24 (Sarp et al. 2018) and the results obtained are in good agreement
with observed values. Our study unveils that the maximum amplitude
of the sunspot area of the whole solar disc will be 1606.49 ± 412.78
millionths of the solar hemispheric area (m.s.h.) and is expected to
occur around 2025 March. We found that the predicted maximum sunspot
areas in the Northern and Southern hemispheres are 731.39 ± 192.7 and
764.89 ± 195.39 m.s.h., respectively, with probable times of maxima
around 2023 September and 2024 August, respectively. These results
indicate that the strength of the sunspot area in solar cycle 25 will
be weaker than or comparable with that in solar cycle 24. Such results
are discussed and compared with other recent forecasts.

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Title: Study of the Magnetic Properties of Sunspot Umbrae
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.; Rudenko,
G. V.
2022ARep...66..116Z Altcode:
The paper presents the results of the study of sunspots, obtained by the
authors and other researchers in recent years. The results regarding
the atmosphere above sunspot umbrae, based on the observational data
in the spectral lines of the upper chromosphere and lower corona,
are discussed. It is shown that individual parameters of the profile
of these lines differ in leading and trailing sunspots. A hypothesis
about the relationship between the parameters of the profiles of these
spectral lines and the parameters of the magnetic field in sunspot
umbrae is stated and tested. A comparative analysis of the magnetic
properties of the umbrae of leading and trailing sunspots in active
regions (ARs) without explosive processes (EPs, id est, formation
of coronal mass ejection with solar flare) is carried out. For the
analysis, only pairs of magnetically coupled (connected by magnetic
field lines) leading and trailing sunspots were selected. It is shown
that the values of a number of magnetic field parameters in sunspot
umbrae and the character of the relationship between them depend on
the type of the sunspots. In particular, in the umbrae of leading and
trailing sunspots of close areas, the maximum and average magnitudes of
the magnetic induction are different. The dependences of the minimum
angle of inclination of the field lines to the radial direction from
the center of the Sun and the average inclination angle of the field
lines on the umbra areas of leading and trailing sunspots are also
different. For magnetically coupled leading and trailing sunspots, it
is shown that the distances from the center of the umbra of each type
of sunspots to the main polarity separation line of the photospheric
field in ARs are different. The paper also discusses the time variation
of various magnetic field parameters of the sunspot umbra separately
for single and magnetically coupled sunspots, as well as sunspots
of magnetically coupled ARs, which we defined as magnetic activity
complexes (MACs). The evolution of the magnetic characteristics of
sunspots, including sunspots in the MACs, during a radical rearrangement
of the magnetic configuration is studied. The influence of EPs on the
characteristics of the magnetic field in sunspots is revealed. One of
the objectives of this work was to reveal the difference between the
properties of sunspots in ARs without EPs and in ARs with various
activities, e.g., with solar flares and the formation of coronal
mass ejections.

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Title: Long-Term Variations in Coronal Hole Areas and Occurrence of
Magnetic Storms with Gradual Commencements
Authors: Veretenenko, S. V.; Ogurtsov, M. G.; Obridko, V. N.; Tlatov,
A. G.
2021Ge&Ae..61..964V Altcode:
In this paper we studied long-term variations in the areas of coronal
holes (CHs) reconstructed on the basis of synoptic Hα charts
for the period 1887-2016 and occurrences of magnetic storms with
gradual commencements. It was found that the temporal variations
in mean yearly values of the CH areas in the northern and southern
hemispheres are characterized by a pronounced ∼11-year periodicity,
but they differ markedly on a multidecadal time scale. The wavelet
spectra of the CH areas in the southern hemisphere, unlike those of
the northern one, demonstrate persistent periodicities of ∼30-35
years, which are also observed in geomagnetic activity and climatic
characteristics. The results of cross-wavelet analysis revealed a link
between annual occurrences of magnetic storms with gradual commencements
and variations in CH areas in both hemispheres. The obtained results
allow us to conclude that the evolution of solar coronal holes may
be considered as a possible factor of the formation of multidecadal
cycles in geomagnetic activity, as well as climatic cycles.

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Title: Solar evolution and extrema: current state of understanding
of long-term solar variability and its planetary impacts
Authors: Nandy, Dibyendu; Martens, Petrus C. H.; Obridko, Vladimir;
Dash, Soumyaranjan; Georgieva, Katya
2021PEPS....8...40N Altcode:
The activity of stars such as the Sun varies over timescales
ranging from the very short to the very long—stellar and planetary
evolutionary timescales. Experience from our solar system indicates that
short-term, transient events such as stellar flares and coronal mass
ejections create hazardous space environmental conditions that impact
Earth-orbiting satellites and planetary atmospheres. Extreme events
such as stellar superflares may play a role in atmospheric mass loss
and create conditions unsuitable for life. Slower, long-term evolutions
of the activity of Sun-like stars over millennia to billions of years
result in variations in stellar wind properties, radiation flux, cosmic
ray flux, and frequency of magnetic storms. This coupled evolution of
star-planet systems eventually determines planetary and exoplanetary
habitability. The Solar Evolution and Extrema (SEE) initiative of the
Variability of the Sun and Its Terrestrial Impact (VarSITI) program of
the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) aimed
to facilitate and build capacity in this interdisciplinary subject
of broad interest in astronomy and astrophysics. In this review, we
highlight progress in the major themes that were the focus of this
interdisciplinary program, namely, reconstructing and understanding
past solar activity including grand minima and maxima, facilitating
physical dynamo-model-based predictions of future solar activity,
understanding the evolution of solar activity over Earth's history
including the faint young Sun paradox, and exploring solar-stellar
connections with the goal of illuminating the extreme range of activity
that our parent star—the Sun—may have displayed in the past,
or may be capable of unleashing in the future.

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Title: Estimating the Energy of Solar and Stellar Superflares
Authors: Katsova, M. M.; Obridko, V. N.; Sokoloff, D. D.; Livshits,
I. M.
2021Ge&Ae..61.1063K Altcode:
We discuss the current observations of the most powerful non-steady
phenomena on solar-like stars. While remaining within even the most
extreme solar ideas, it is very problematic to get the flare energy
more than (3-5) × 1034 erg, which is apparently an absolute
upper limit for solar-type flares. For explanation of the higher flare
energy, about of 1036 erg, one need to adopt that spots
with the magnetic field strength of a few kG should cover more than 30%
of a hemisphere. This estimate leads to a mean magnetic field around 1
kG. New observational evidences for a presence of the strong magnetic
fields on solar-like stars appeared recently. We discuss to what extent
it is necessary to change the mechanisms of convection and dynamo with
a corresponding change in the models of the atmosphere. We consider
possible ways of solving the problem of the energy of superflares.

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Title: Zonal harmonics of solar magnetic field for solar cycle
forecast
Authors: Obridko, V. N.; Sokoloff, D. D.; Pipin, V. V.; Shibalva,
A. S.; Livshits, I. M.
2021JASTP.22505743O Altcode: 2021arXiv210810527O
According to the scheme of action of the solar dynamo, the poloidal
magnetic field can be considered a source of production of the toroidal
magnetic field by the solar differential rotation. From the polar
magnetic field proxies, it is natural to expect that solar Cycle 25
will be weak as recorded in sunspot data. We suggest that there are
parameters of the zonal harmonics of the solar surface magnetic field,
such as the magnitude of the l = 3 harmonic or the effective multipole
index, that can be used as a reasonable addition to the polar magnetic
field proxies. We discuss also some specific features of solar activity
indices in Cycles 23 and 24.

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Title: Long-term evolution of coronal holes on the Sun and occurrence
frequencies of magnetic storms with gradual commencements
Authors: Veretenenko, S.; Ogurtsov, M.; Obridko, V.; Tlatov, A.
2021JPhCS2103a2038V Altcode:
Long-term evolution of areas with open configuration of magnetic field
(coronal holes) on the Sun reconstructed on the basis of H-alpha
synoptic charts for the period 1887-2016 was studied and compared
with annual occurrence frequencies of magnetic storms with gradual
(GC) commencements. It was found that correlation between yearly
values of coronal hole (CH) areas and sunspot numbers with no time
shift is negative and not strong, but increases up to ~0.6-0.7 when CH
areas are delayed by 4-5 years relative to sunspot numbers. Temporal
variations of CH areas in the Northern and Southern hemispheres are
characterized by dominant ~11-year periodicities; however, they differ
significantly on the multidecadal time scale. The wavelet spectra
of CH areas in the Southern hemisphere, unlike those in the Northern
one, reveal persistent periodicities of ~30-35 years on the studied
time interval. Similar periodicities of ~30-35 years are observed in
annual occurrences of GC magnetic storms which are caused by high-speed
streams of solar wind from coronal holes. The results of cross wavelet
analysis of annual occurrence frequencies of GC magnetic storms and
areas of coronal holes revealed common periodicities ~11, ~35 and ~60
years which confirmed a close link of these storms with the evolution
of large-scale magnetic fields on the Sun.

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Title: Medium-Term Oscillations of the Solar Activity
Authors: Obridko, V. N.; Sokoloff, D. D.; Pipin, V. V.; Shibalova,
A. S.
2021simi.conf...66O Altcode:
Besides the well-known 11-year cycle, longer and shorter characteristic
periods can be isolated in variations of the parameters of
helio-geophysical activity. In geomagnetic variations, one can also
isolate oscillations with characteristic periods of 5-6 years (QSO)
and 2-3 years (QBO). Periods of ~36 and ~60 years were revealed
in geomagnetic activity variations and a ~60-year periodicity, in
correlation between the pressure in the lower atmosphere and the
solar activity. We have considered 5-6-year periodicities observed
in variations of the sunspot numbers and the intensity of the dipole
component of the solar magnetic field. Comparison with different
magnetic dynamo models allowed us to conjecture the origin of these
oscillations. As a result of the study, we conclude that the 5-6-year
activity variations are related to the processes of nonlinear saturation
of the dynamo in the solar interior. Quasi-biennial oscillations are
actually separate pulses related little to each other. Therefore, the
methods of the spectral analysis do not reveal them over large time
intervals. They are a direct product of local fields, are generated
in near-surface layers, and are reliably recorded only in the epochs
of high solar activity.

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Title: Solar large-scale magnetic field and cycle patterns in
solar dynamo
Authors: Obridko, V. N.; Pipin, V. V.; Sokoloff, D.; Shibalova, A. S.
2021MNRAS.504.4990O Altcode: 2021arXiv210406808O; 2021MNRAS.tmp.1043O
We compare spectra of the zonal harmonics of the large-scale magnetic
field of the Sun using observation results and solar dynamo models. The
main solar activity cycle as recorded in these tracers is a much more
complicated phenomenon than the eigen solution of solar dynamo equations
with the growth saturated by a back reaction of the dynamo-driven
magnetic field on solar hydrodynamics. The nominal 11(22)-yr cycle as
recorded in each mode has a specific phase shift varying from cycle
to cycle; the actual length of the cycle varies from one cycle to
another and from tracer to tracer. Both the observation and the dynamo
model show an exceptional role of the axisymmetric ℓ5
mode. Its origin seems to be readily connected with the formation and
evolution of sunspots on the solar surface. The results of observations
and dynamo models show a good agreement for the low ℓ1
and ℓ3 modes. The results for these modes do not differ
significantly for the axisymmetric and non-axisymmetric models. Our
findings support the idea that the sources of the solar dynamo arise
as a result of both the distributed dynamo processes in the bulk of
the convection zone and the surface magnetic activity.

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Title: Current Sheets, Plasmoids and Flux Ropes in the
Heliosphere. Part II: Theoretical Aspects
Authors: Pezzi, O.; Pecora, F.; Le Roux, J.; Engelbrecht, N. E.; Greco,
A.; Servidio, S.; Malova, H. V.; Khabarova, O. V.; Malandraki, O.;
Bruno, R.; Matthaeus, W. H.; Li, G.; Zelenyi, L. M.; Kislov, R. A.;
Obridko, V. N.; Kuznetsov, V. D.
2021SSRv..217...39P Altcode: 2021arXiv210105007P
Our understanding of processes occurring in the heliosphere
historically began with reduced dimensionality - one-dimensional
(1D) and two-dimensional (2D) sketches and models, which aimed to
illustrate views on large-scale structures in the solar wind. However,
any reduced dimensionality vision of the heliosphere limits the
possible interpretations of in-situ observations. Accounting for
non-planar structures, e.g. current sheets, magnetic islands, flux
ropes as well as plasma bubbles, is decisive to shed the light on
a variety of phenomena, such as particle acceleration and energy
dissipation. In part I of this review, we have described in detail the
ubiquitous and multi-scale observations of these magnetic structures in
the solar wind and their significance for the acceleration of charged
particles. Here, in part II, we elucidate existing theoretical paradigms
of the structure of the solar wind and the interplanetary magnetic
field, with particular attention to the fine structure and stability of
current sheets. Differences in 2D and 3D views of processes associated
with current sheets, magnetic islands and flux ropes are discussed. We
finally review the results of numerical simulations and in-situ
observations, pointing out the complex nature of magnetic reconnection
and particle acceleration in a strongly turbulent environment.

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Title: Current Sheets, Plasmoids and Flux Ropes in the
Heliosphere. Part I. 2-D or not 2-D? General and Observational Aspects
Authors: Khabarova, O.; Malandraki, O.; Malova, H.; Kislov, R.;
Greco, A.; Bruno, R.; Pezzi, O.; Servidio, S.; Li, Gang; Matthaeus,
W.; Le Roux, J.; Engelbrecht, N. E.; Pecora, F.; Zelenyi, L.; Obridko,
V.; Kuznetsov, V.
2021SSRv..217...38K Altcode:
Recent accumulation of a critical mass of observational material from
different spacecraft complete with the enhanced abilities of numerical
methods have led to a boom of studies revealing the high complexity
of processes occurring in the heliosphere. Views on the solar wind
filling the interplanetary medium have dramatically developed from the
beginning of the space era. A 2-D picture of the freely expanding solar
corona and non-interacting solar wind structures described as planar
or spherically-symmetric objects has dominated for decades. Meanwhile,
the scientific community gradually moved to a modern understanding
of the importance of the 3-D nature of heliospheric processes and
their studies via MHD/kinetic simulations, as well as observations
of large-scale flows and streams both in situ and remotely, in white
light and/or via interplanetary scintillations. The new 3-D approach
has provided an opportunity to understand the dynamics of heliospheric
structures and processes that could not even be imagined before within
the 2-D paradigm. In this review, we highlight a piece of the puzzle,
showing the evolution of views on processes related to current sheets,
plasmoids, blobs and flux ropes of various scales and origins in the
heliosphere. The first part of the review focuses on introducing these
plasma structures, discussing their key properties, and paying special
attention to their observations in different space plasmas.

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Title: Corrigendum to "Long-term variability in occurrence
frequencies of magnetic storms with sudden and gradual commencements"
[J. Atmos. Sol.Terr. Phys. 205 (2020) 105295]
Authors: Veretenenko, S.; Ogurtsov, M.; Obridko, V.
2021JASTP.21405549V Altcode:
The authors regret that an error was found in the data presented in
Fig.6, which displays local and global wavelet power spectra of major
(strong and very strong) and moderate magnetic storms with gradual
(GC) commencements. We note that the spectra of major magnetic storms
(Figs.6a and b) are shown incorrectly, representing those of moderate
storms after subtraction of the linear trend. The correct wavelet
spectra of major GC storms are presented here in Fig.1, which replaces
Fig.6 in the paper. It is seen that occurrence frequencies of these
storms are characterized by persistent long-term variations, as it
is stated in the paper, but their spectra do not reveal dominant
periodicities of ~36, but those of ~50 years. The periodicities of
~36 years close to the Brückner climatic cycle dominate only in the
spectra of moderate GC storms. The spectra of both major and moderate
GC storms also show noticeable ~60-year variability.

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Title: Large-scale magnetic field of the Sun: Evolution of ideas
Authors: Obridko, V. N.
2021A&AT...32..305O Altcode:
In this paper, we discuss the evolution of the concept of the
large-scale solar magnetic field. The priority of the large-scale
field was established about 60 years ago, when it became clear that
the spatial structure and evolution of the solar activity obey certain
large-scale laws. The analogy between coronal holes and sunspots
and the formation of global complexes of activity are discussed. A
technique is presented for a quantitative analysis of the large-scale
field over long time intervals based on the hypothesis of potential
field in the chromosphere and corona. The concept of the global
magnetic-field indices is introduced, and their relationship with
other heliogeophysical indices is shown. A negative correlation has
been found between the magnitude of the magnetic field and the angular
rotation rate of the Sun.

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Title: Some Features of the Present-day Transition Period in Solar
Activity
Authors: Obridko, V. N.; Abunin, A. A.; Georgieva, K.; Kirov, B.;
Shelting, B. D.; Livshits, I. M.
2020Ge&Ae..60.1007O Altcode:
Various geophysical indices and their prognostic value were analyzed
in (Obridko et al., 2013; Kirov et al., 2013, 2015, 2017; Georgieva
et al., 2015, 2018). Two indices have been selected for the analysis
(total annual Dst values, and duration of a storm). It is important to
note that, unlike the other indices of solar and geophysical activity,
the summary Dst index does not show violation of the Gnevyshev-Ohl
rule. The analysis of annual mean Dst values reveals a clearly
pronounced decrease in activity, at least since the 1980-ies. This
allows us to suggest that we are at the descending branch of a secular
cycle or on the threshold of a Grand Minimum. The decrease in solar
activity is corroborated by the analysis of Forbush effects, solar
wind speed, and intensity of the near-Earth magnetic field.

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Title: Magnetic Coupling of the Solar Hemispheres During the Solar
Cycle
Authors: Obridko, V. N.; Fainshtein, V. G.; Zagainova, Y. S.; Rudenko,
G. V.
2020SoPh..295..149O Altcode:
This work is devoted to the study of peculiarities in the magnetic
coupling of the solar hemispheres over a solar activity cycle. Two
approaches have been used. We have studied (i) the magnetic coupling of
active regions (ARs) located in different hemispheres in the vicinity of
the central meridian and, simultaneously, in the vicinity of the equator
and (ii) the properties and time variation of the meridional component
of the equatorial magnetic field derived from a potential-field source
surface (PFSS) reconstruction at the heliocentric distance of 1.1
solar radii. In the first case, it was shown that most of the ARs
in the selected pairs were magnetically connected by field lines in
their leading parts. In the second case, the magnetic field monthly
mean meridional component, Bθ, in the equatorial plane,
which magnetically connects the two hemispheres, displayed a cyclic
time variation. In the process, the extreme values of Bθ
(both positive and negative) coincided in time with the sunspot
maxima, and the amplitude of the Bθ extreme values
decreased with decreasing height of the sunspot activity cycle. The
sign of the Bθ extreme value was opposite to the sign of
the forthcoming extreme value of the polar field, while the sign of
Bθ coincided with that of the field lines connecting the
leading spots. This means that the polar field is indeed generated by
the trailing spots of ARs, and the magnetic flux of the leading spots
closes through the equator.

---------------------------------------------------------
Title: Solar Quadrupole in Tensor Description
Authors: Shibalova, A. S.; Obridko, V. N.; Sokolov, D. D.; Pipin, V. V.
2020ARep...64..855S Altcode:
The cyclic variations in the quadrupole component of the solar magnetic
field is studied in tensor description. The results are consistent
with the classical description of the quadrupole using spherical
functions, and the mathematical apparatus of tensor algebra allows
one to compare the observed changes in the magnetic quadrupole and the
changes predicted by the dynamo theories. In conclusion, the quadrupole
properties can be adequately described by solar dynamo models that
assume deviations from the dipole symmetry without the independent
excitation of the quadrupole symmetry modes.

---------------------------------------------------------
Title: Young Sun, galactic processes, and origin of life
Authors: Obridko, Vladimir N.; Ragulskaya, Maria V.; Khramova,
Elizaveta G.
2020JASTP.20805395O Altcode:
The paper deals with the dynamics of the young Sun, physical conditions
in the early Solar System and on the Earth. An extended interpretation
of the faint young Sun paradox and its possible solutions are
proposed. Various hypotheses are discussed including their advantages
and disadvantages. The faint young Sun paradox follows from the Standard
Solar Model with the conservation of mass condition. However, the mass
of the Sun did not remain constant during its evolution. It was steadily
decreasing, mainly in the first 2-2.5 billion years. But even with the
most optimistic estimates, the uneven loss of mass during the evolution
of our star is unable to fully compensate for the lack of luminosity
reaching the surface of the early Earth. The primary biosphere had
to search for alternative - e.g., radiation, chemical or geothermal -
sources of energy. The prevalent configurations of solar magnetic fields
also changed in the course of evolution, the strong quadrupole fields
dominating at the early stages. At the age of about 2-2.5 billion
years and the rotation period of about 15 days, the dipole magnetic
field with large mass outflow from coronal holes begins to dominate,
and the steady solar wind becomes the main mechanism of mass loss in
the Sun in the following two billion years. The activity of the early
Sun was much higher than it is today. The high-frequency (gamma-,
X-ray, and UV) radiation, radio emission, coronal mass ejections,
and solar cosmic rays exceeded the present-day values by 2-3 orders
of magnitude. The article emphasizes the role of the dynamics of the
young Sun, cosmic rays, magnetic field and other protective shells
of the Earth as factors determining the occurrence, selection, and
development of the first living systems.

---------------------------------------------------------
Title: Shape of solar cycles and mid-term solar activity oscillations
Authors: Sokoloff, D. D.; Shibalova, A. S.; Obridko, V. N.; Pipin,
V. V.
2020MNRAS.497.4376S Altcode: 2020arXiv200714779S
The evolution of solar activity comprises, apart from the well-known
11-year cycle, various temporal scales ranging from months up to the
secondary cycles known as mid-term oscillations. Its nature deserves
a physical explanation. In this work, we have considered the 5-6 year
oscillations as derived both from sunspots and solar magnetic dipole
time series. Using a solar dynamo model, we have deduced that these
variations may be a manifestation of dynamo non-linearities and the
non-harmonic shape of the solar activity cycles. We have concluded
that the observed mid-term oscillations are related to the non-linear
saturation of dynamo processes in the solar interior.

---------------------------------------------------------
Title: On Superflares on the Sun and Stars
Authors: Katsova, M. M.; Obridko, V. N.; Sokoloff, D. D.; Livshits,
I. M.
2020simi.conf...25K Altcode:
We discuss the current observations of the most powerful non-steady
phenomena on solarlike stars. While remaining within even the most
extreme solar ideas, there is problematic to get the flare energy more
than (3-5)x10(exp 34)erg, which is apparently an absolute upper limit
for solar-type flares. For explanation of the higher flare energy, about
of 10(exp 36) erg, one need to adopt that spots with the magnetic field
strength of a few kG should cover more than 30 % of a hemisphere. This
estimate leads to a mean magnetic field around 1kG. New observational
evidences for a presence of the strong relict magnetic fields on
solar-like stars appeared recently. We discuss to what extent it is
necessary to change the mechanisms of convection and dynamo with a
corresponding change in the models of the atmosphere. We consider
possible ways of solving the problem of the energy of superflares.

---------------------------------------------------------
Title: Long-term variability in occurrence frequencies of magnetic
storms with sudden and gradual commencements
Authors: Veretenenko, S.; Ogurtsov, M.; Obridko, V.
2020JASTP.20505295V Altcode:
Long-term variations in annual frequencies of occurrence of magnetic
storms with sudden and gradual commencements were studied on the base
of the data from IZMIRAN and Slutsk (Pavlovsk) magnetic observatories
for the period 1878-2015. It was found that occurrences of strong and
moderate magnetic storms with gradual commencements are characterized
by a pronounced variability on the multidecadal time scale. Their
wavelet spectra reveal strong periodicities of ~36 years (close to
the climatic Brückner cycle), as well as less pronounced ~60-year
and ~90-year ones throughout the entire time interval under study. The
occurrences of strong, moderate and weak magnetic storms with sudden
commencements are characterized by dominating ~11-year periodicities,
whereas long-term variations are substantially weaker. The obtained
results provide evidence for a different temporal evolution of local
and global solar magnetic fields responsible for solar agents (CMEs
and high-speed solar wind streams from coronal holes) contributing
to the development of these types of magnetic storms. The obtained
results allow suggesting a possible contribution of solar/geomagnetic
activity to the formation of climatic oscillations on the multidecadal
time scale.

---------------------------------------------------------
Title: Differential rotation of the solar corona and its importance
for helioseismology
Authors: Obridko, Vladimir; Badalyan, Olga
2020EGUGA..22.3710O Altcode:
It is shown that the solar corona rotates differentially at all
heliocentric distances up to the source surface. As the distance
increases, the differential rotation gradient decreases, and the
rotation becomes more and more rigid. At small distances, the corona
at latitudes above ≈ ± 40° rotates faster than the photosphere
at the same latitudes. The type of the rotation depends also on the
phase of the activity cycle. The differential rotation gradient is
the largest in the vicinity of the cycle minimum. It is shown that
time variations in the coronal rotation characteristics are associated
with the tilt of the magnetic equator of the Sun. Based on the concept
that the differential rotation of the corona reflects the rotation of
deep subphotospheric layers, we compared the changes in the coronal
rotation characteristics with distance with the helioseismic data and
showed their satisfactory agreement. The results obtained allow us to
suggest that the rotation of the solar corona can be used as indicator
of the differential rotation of subphotospheric layers and calculate
the nature of some current sheets in heliosphere/

---------------------------------------------------------
Title: Solar Activity Indices for Ionospheric Parameters in the 23rd
and 24th Cycles
Authors: Deminov, M. G.; Nepomnyashchaya, E. V.; Obridko, V. N.
2020Ge&Ae..60....1D Altcode:
Characteristics of changes in the solar activity indices (the flux
of the solar radio emission at a wavelength of 10.7 cm F and the new
version of the relative sunspot number Ri) and the ionospheric index
of this activity T in the 23rd and 24th solar cycles, which were low
by the amplitude of solar and geomagnetic activity, are analyzed. The
running mean over 12 months and smoothed (by a 24-month filter) values
of these indices are considered in the analysis. It is found that
the relation between the T and F indices was on average stable for
these cycles and did not differ from the previous solar cycles. The
relation between the T and Ri indices changed with time in the 23rd
and 24th cycles and was different from the previous cycles. Moreover,
a distinct hysteresis effect in the dependence of the smoothed values
of T on Ri was observed in the 24th cycle when different values of T
corresponded to a fixed value of Ri in the growing and declining phases
of the solar cycle. This effect was absent in the dependence of T on
F. Thus, it is confirmed that the F index is a more exact indicator
of solar activity for the ionosphere than Ri.&lt;/sec&gt;

---------------------------------------------------------
Title: Cycle-dependent and cycle-independent surface tracers of
solar magnetic activity
Authors: Sokoloff, D. D.; Obridko, V. N.; Livshits, I. M.; Shibalova,
A. S.
2020IAUGA..30..342S Altcode:
We consider several tracers of magnetic activity that separate
cycle-dependent contributions to the background solar magnetic field
from those that are independent of the cycle. The main message is that
background fields include two relative separate populations. The
background fields with a strength up to 100 Mx cm-2
are very poorly correlated with the sunspot numbers and vary little
with the phase of the cycle. In contrast, stronger magnetic fields
demonstrate pronounced cyclic behaviour. Small-scale solar magnetic
fields demonstrate features of fractal intermittent behaviour, which
requires quantification. We investigate how the observational estimate
of the solar magnetic flux density B depends on resolution D in order
to obtain the scaling In BD = -k In D + a in a reasonably
wide range. The quantity k demonstrates cyclic variations typical
of a solar activity cycle. k depends on the magnetic flux density,
i.e. the ratio of the magnetic flux to the area over which the flux
is calculated, at a given instant. The quantity a demonstrates some
cyclic variation, but it is much weaker than in the case of k. The
scaling is typical of fractal structures. The results obtained trace
small-scale action in the solar convective zone and its coexistence
with the conventional large-scale solar dynamo based on differential
rotation and mirror-asymmetric convection. Here we discuss the message
for solar dynamo studies hidden in the above results.

---------------------------------------------------------
Title: Cyclic variations in the main components of the solar
large-scale magnetic field
Authors: Obridko, V. N.; Sokoloff, D. D.; Shelting, B. D.; Shibalova,
A. S.; Livshits, I. M.
2020MNRAS.492.5582O Altcode: 2020arXiv200105433O
We consider variations of the dipole and quadrupole components of the
solar large-scale magnetic field. Both axial and equatorial dipoles
exhibit a systematic decrease during the past four cycles, in accordance
with the general decrease of solar activity. The transition of the pole
of a dipole from the polar region to the midlatitudes occurs rather
quickly, so that the longitude of the pole changes little. With time,
however, this inclined dipole region shifts to larger longitudes,
which suggests an acceleration of dipole rotation. The mean rotation
rate exceeds the Carrington velocity by 0.6 per cent. The behaviour
of a quadrupole differs dramatically. Its decrease over the last four
cycles was much smaller than that of the dipole moment. The ratio of
the quadrupole and dipole moments has increased for four cycles more
than twice, in contrast to sunspot numbers, which displayed a twofold
decrease for the same time interval. Regarding quadrupole rotation,
the mean longitude of the poles of one sign decreased by 600° over
four cycles, which suggests that the mean rotation rate was lower than
the Carrington velocity by 0.28 per cent. We do not, however, see any
conclusive evidence that, in the period under discussion, a mode of
quadrupole symmetry was excited in the Sun along with the dipole mode.

---------------------------------------------------------
Title: Physical conditions in the early Solar system and life origin:
compatible models
Authors: Ragulskaya, Mariya; Khramova, Elizaveta; Obridko, Vladimir
2020IAUS..345..347R Altcode:
The article discusses the physical conditions in the early Solar system
and on Earth, determining the origin, selection and development of
the first living systems. The role of the young Sun dynamics, cosmic
rays, magnetic fields and other protective shells of the Earth in the
formation of the biosphere is emphasized. The selection of a single
genetic code, ancient methods of long-term storage of energy and
adaptive technologies of the first living systems occurred under the
influence of cosmological and geophysical factors. A hypothesis was
suggested that the accumulation of energy in polyphosphates without
the participation of solar radiation could have ensured the survival
of the primary biosphere in the conditions of the low luminosity of
the young Sun.

---------------------------------------------------------
Title: Solar Corona as Indicator of Differential Rotation of
Subphotospheric Layers
Authors: Obridko, V. N.; Badalyan, O. G.
2020CosRe..57..407O Altcode:
In our earlier work [2-4], we proposed using the coronal magnetic field
as an implicit tracer when studying the properties of differential
rotation of the solar corona. At present, this is virtually the
only way to study the rotation of the Sun at large heliocentric
distances up to the source surface. In the present work, calculations
of the coronal magnetic field have been extended over a longer time
interval, till December 31, 2015. It is shown that the solar corona
rotates differentially at all heliocentric distances up to the source
surface. The differential rotation gradient decreases with distance. As
we approach the source surface, the corona rotation becomes more
rigid, but even at large heliocentric distances it remains slightly
differential. We believe that the differential rotation of the solar
corona reflects the rotation of deep subphotospheric layers. In this
case, the behavior of the coronal rotation characteristics can be
used as indicator of differential rotation of the subphotospheric
layers. We have compared the changes in the coronal rotation
characteristics with distance with helioseismic data and obtained a
satisfactory agreement. Cycle variations in the differential rotation
of subphotospheric layers have been investigated for the first time.

---------------------------------------------------------
Title: Analysis of the Hemispheric Sunspot Number Time Series for
the Solar Cycles 18 to 24
Authors: Chowdhury, P.; Kilcik, A.; Yurchyshyn, V.; Obridko, V. N.;
Rozelot, J. P.
2019SoPh..294..142C Altcode:
In this article, we investigate temporal and periodic variations of the
hemispheric sunspot number using sunspot data from Kanzelhöhe Solar
Observatory (KSO) for the time period of 1944 - 2017, which covers Solar
Cycles 18 to 23 and almost the entire Solar Cycle 24 (2009 - 2017). The
KSO data set was verified against the International Sunspot Number
(ISSN) data. Temporal and periodic variations in the KSO data were
analyzed using cross-correlation analysis, Morlet wavelet and multitaper
(MTM) period analysis methods. We find that: i) sunspot numbers, as
derived from both KSO and ISSN time series, are highly correlated with
one another; ii) the temporal evolution of the sunspot number differs
from one hemisphere to another with the solar cycle peaking at different
times in each hemisphere; iii) the northern hemisphere showed two-
and seven-month lead in Solar Cycles 18 and 19, respectively, while
the southern hemisphere was leading in the rest of the cycles with
the varying lead time ranging from 2 to 14 months; iv) apart from the
fundamental mode of ≈ 11 years, Solar Cycle, the KSO data also show
several midterm variations in the opposite hemispheres, specifically,
Rieger-type and quasi-biennial periodicities - the detected midterm
periodicities also differ in the northern and southern hemispheres;
v) our results confirm the Waldmeier effect, which correlates the rise
time with the cycle amplitude using the new sunspot data set from KSO.

---------------------------------------------------------
Title: The Young Sun, Conditions on the Early Earth, and the Origin
of Life
Authors: Ragulskaya, M. V.; Khramova, E. G.; Obridko, V. N.
2018Ge&Ae..58..877R Altcode:
The article analyzes the existing theoretical models of the formation
of the solar system and the early physical conditions on Earth from
the point of view of the possibility for the development of life in its
present form. We show that the origin of the biosphere and geomagnetic
field was determined not only by the conditions on the Earth itself but
also by the dynamics of the early Sun, the migration of giant planets,
and the formation of the Earth-Moon system. Also considered are the
possibilities for the search for bacterial life beyond the Earth:
on Mars, on satellites of Giant planets, on the outer asteroid belt,
and on exoplanets.

---------------------------------------------------------
Title: Differential Rotation of the Solar Corona from Magnetic
Field Data
Authors: Badalyan, O. G.; Obridko, V. N.
2018AstL...44..727B Altcode:
A method for investigating the differential rotation of the solar
corona using the coronal magnetic field as a tracer is proposed. The
magnetic field is calculated in the potential approximation from
observational data at the photospheric level. The time interval from
June 24, 1976, to December 31, 2004, is considered. The magnetic field
has been calculated for all latitudes from the equator to ±75° with a
5° step at distances from the base of the corona 1.0 R ⊙
to 2.45 R ⊙ near the source surface. The coronal rotation
periods at 14 distances from the solar center have been determined by
the method of periodogram analysis. The coronal rotation is shown to
become progressively less differential with increasing heliocentric
distance; it does not become rigid even near the source surface. The
change in the coronal rotation periods with time is considered. At
the cycleminimumthe rotation has been found to bemost differential,
especially at small distances from the solar center. The change in
coronal rotation with time is consistent with the tilt of the solar
magnetic equator. The results from the magnetic field are compared with
those obtained from the brightness of the green coronal Fe XIV 530.3
nm line. The consistency between these results confirms the reliability
of the proposed method for studying the coronal rotation. Studying the
rotation of the coronal magnetic field gives hope for the possibility
of using this method to diagnose the differential rotation in
subphotospheric layers.

---------------------------------------------------------
Title: Magnetic Field as a Tracer for Studying the Differential
Rotation of the Solar Corona
Authors: Badalyan, O. G.; Obridko, V. N.
2018SoPh..293..128B Altcode: 2018arXiv180805515B
The characteristics of differential rotation of the solar corona for
the period 1976 - 2004 were studied as a function of the distance from
the center of the Sun. For this study, we developed a method using the
coronal magnetic field as a tracer. The field in a spherical layer
from the base of the corona up to the source surface was determined
from photospheric measurements. Calculations were performed for
14 heliocentric distances from the base of the corona up to 2.45
R⊙ solar radii (the vicinity of the source surface) and
from the equator to ±75∘ of latitude at 5∘
steps. For each day, we calculated three spherical components, which
were then used to obtain the field strength. The coronal rotation
periods were determined by the periodogram method. The rotation periods
were calculated for all distances and latitudes under consideration. The
results of these calculations make it possible to study the distribution
of the rotation periods in the corona depending on distance, time, and
phase of the cycle. The variations in the coronal differential rotation
during the time interval 1976 - 2004 were as follows: the gradient
of differential rotation decreased with the increase of heliocentric
distance; the rotation remaining differential even in the vicinity
of the source surface. The highest rotation rates (shortest rotation
periods) were recorded at the cycle minimum at small heliospheric
distances, i.e. small heights in the corona. The lowest rotation
rate was observed at the middle of the ascending branch at large
distances. At the minimum of the cycle, the differential rotation is
most clearly pronounced, especially at small heliocentric distances. As
the distance increases, the differential rotation gradient decreases in
all phases. The results based on magnetic data and on the brightness of
the coronal green line 530.3 nm Fe XIV used earlier show a satisfactory
agreement. Since the rotation of the magnetic field at the corresponding
heights in the corona is probably determined by the conditions in the
field generation region, an opportunity arises to use this method for
diagnostics of differential rotation in the subphotospheric layers.

---------------------------------------------------------
Title: Solar activity in the following decades
Authors: Obridko, V.; Georgieva, K.
2018JASTP.176....1O Altcode:
Welcome to the JASTP Special Issue on Expected Evolution of Solar
Activity in the Following Decades.

---------------------------------------------------------
Title: Properties of the Ionosphere at the Fall and Minimum Phases
of the Latest Solar Cycles
Authors: Deminov, M. G.; Nepomnyashchaya, E. V.; Obridko, V. N.
2018stpc.conf...72D Altcode:
The properties of the ionosphere in solar cycles 23 and 24 were studied
on the basis of the comparison of the solar activity indices (F10.7
and Ri) with the ionospheric index of this activity T. It was found
that in cycle 24 the hysteresis effect was observed in the dependence
of T on Ri. This effect was absent in the dependence of T on F10.7.

---------------------------------------------------------
Title: Forecasting the sunspot maximum through an analysis of
geomagnetic activity
Authors: Kirov, B.; Asenovski, S.; Georgieva, K.; Obridko, V. N.;
Maris-Muntean, G.
2018JASTP.176...42K Altcode:
In the present work we show that it is possible to predict the maximum
sunspot number for a particular solar cycle from the maximum value of
the solar dipole magnetic field of the previous cycle. Based on the
measured dipole field maximum, we determine the geomagnetic activity
in the upcoming solar minimum during the intervals when the Earth is
not exposed to CME and HSS influences. The physical meaning of the
relationship between the geomagnetic activity in the solar activity
minimum and the maximum value of the solar dipole magnetic field is
that the basic factor determining the geomagnetic activity during
the minimum is not the heliospheric current sheet thickness but the
physical parameters of the slow solar wind in this period. Then,
based on the established relationship between the average geomagnetic
activity at the specified minimum and the next solar maximum, we can
predict the sunspot maximum of the next solar cycle.

---------------------------------------------------------
Title: Do the sunspot umbra magnetic field characteristics vary
during flares and coronal mass ejections?
Authors: Zagainova, Iuliia; Obridko, Vladimir; Rudenko, George;
Fainshtein, Victor
2018cosp...42E3795Z Altcode:
We found variations in the sunspot umbra magnetic field characteristics
within active regions (ARs), where eruptive events (solar flares,
coronal mass ejections (CMEs)) originated. The behavior of the
maximum of the module of magnetic induction B_{max}, the minimum
inclination of the magnetic field lines to the normal α_{min}
and their averages values (B_{mean} and α_{mean}) within umbrae
were analyzed. A change of behavior of the magnetic field parameters
after flare beginning is observed. Thus, for example, during 3 hours
before a solar flare/eruption the _min angle in umbrae of the sunspots
closely located to the "feet" of an eruptive rope is increasing to a
larger values (4° through 10°). Later a strong decreasing over 1 _
3 hours after the flare onset to small values (≤1°) is observed. At
the same time the α_{mean} angle varies essentially more weakly. This
implies that the magnetic tube from the umbra of such sunspots after
the flare onset deflects from the initial position almost as a whole,
i.e. without essential transformation in the distribution of the
magnetic field lines inside the tube.

---------------------------------------------------------
Title: Sources and transport of energetic particles at high
heliolatitudes
Authors: Khabarova, Olga; Bemporad, Alessandro; Obridko, Vladimir;
Malandraki, Olga; Malova, Helmi; Kislov, Roman; Kuznetsov, Vladimir;
Cremades, Hebe; Kharshiladze, Alexander; Merenda, Luciano A.
2018cosp...42E1739K Altcode:
Understanding the origin and transport of energetic particles of
keV-MeV energies throughout the heliosphere still represents one of the
biggest problems of space physics. Our knowledge of the propagation of
energetic particles is mostly based on theoretical predictions compared
with spacecraft observations at low heliolatitudes. Meanwhile, the
occurrence of energetic particles at high heliolatitudes is even more
puzzling since only one spacecraft, Ulysses, flew over the poles of
the Sun and provided information on the energetic particle properties
far above the ecliptic plane. Ulysses observations show that energetic
particle flux enhancements occur at heliolatitudes over 40 degrees
at both solar maximum and minimum conditions (see, e.g., Smith et
al. 2001; Sanderson et al. 2003; Lario et al. 2004; Sanderson 2004;
Malandraki et al. 2009). This suggests various scenarios of particle
transport. Energetic particles of keV-MeV energies should propagate
mainly along magnetic field lines, but if a source is an active region
at low latitudes or an ICME, their detection at high latitudes can be
explained by particle diffusion across magnetic field lines either in
the solar wind or in the corona. In any event, sources of energetic
particles observed above the ecliptic during solar maxima are more
or less well identified.Interpretations of observations of keV-MeV
energetic particles in polar regions during solar minima are more
complicated. The association of energetic particle flux enhancements
in the polar heliosphere with corotating interaction regions, the
main sources of accelerated particles in quiet times, is sometimes
unsuccessful since there are no signatures of cross-field diffusion or
particle streaming from distant heliocentric distances back to the Sun
as it was presumed. The existence of long-lived conic (or cylindrical)
current sheets (CCSs) in the polar solar wind can naturally solve
this problem (Khabarova et al. 2017). It has been recently found
that CCSs are low-beta and low-speed structures formed within polar
coronal holes. CCS stability is supported by the tornado-like magnetic
field. The occurrence of magnetic separators near the poles in solar
minima is confirmed independently by reconstructions of the coronal
magnetic field based on photospheric magnetic field charts. We show
evidence for association of energetic particles observed by Ulysses
above the pole with reconnection polar jets located at the circle-shaped
touchdown of a CCS. Therefore, it is demonstrated that CCSs might serve
as channels for energetic particles accelerated in the solar corona by
magnetic reconnection, which sheds light on the mystery of energetic
particles observed at high heliolatitudes. This work is partly supported
by the International Space Science Institute (ISSI) in the framework
of International Team 405 entitled "Current Sheets, Turbulence,
Structures and Particle Acceleration in the Heliosphere." and RFBR
grants 16-02-00479, 17-02-00300 and 17-02-01328. Khabarova O.V. et al.,
High-latitude conic current sheets in the solar wind, The Astrophysical
Journal, 836, 108, 1, 2017, https://doi.org/10.3847/1538-4357/836/1/108

---------------------------------------------------------
Title: Parameters of the Geomagnetic Activity, Thermosphere, and
Ionosphere for the Ultimately Intense Magnetic Storm
Authors: Deminov, M. G.; Belov, A. V.; Nepomnyashchaya, E. V.; Obridko,
V. N.
2018Ge&Ae..58..501D Altcode:
Equations of regression are derived for the intense magnetic
storms of 1957-2016. They reflect the nonlinear relation between Dst
min and the effective index of geomagnetic activity Ap(τ)
with a timeweighted factor τ. Based on this and on known estimations
of the upper limit of the magnetic storm intensity ( Dst min
=-2500 nT), the maximal possible value Ap(τ)max 1000 nT
is obtained. This makes it possible to obtain initial estimates of
the upper limit of variations in some parameters of the thermosphere
and ionosphere that are due to geomagnetic activity. It is found, in
particular, that the upper limit of an increase in the thermospheric
density is seven to eight times larger than for the storm in March
1989, which was the most intense for the entire space era. The maximum
possible amplitude of the negative phase of the ionospheric storm in the
number density of the F 2-layer maximum at midlatitudes is
nearly six times higher than for the March 1989 storm. The upper limit
of the F 2-layer rise in this phase of the ionospheric storm
is also considerable. Based on qualitative analysis, it is found that
the F 2-layer maximum in daytime hours at midlatitudes for
these limiting conditions is not pronounced and even may be unresolved
in the experiment, i.e., above the F 1-layer maximum, the
electron number density may smoothly decrease with height up to the
upper boundary of the plasmasphere.

---------------------------------------------------------
Title: The evolution of flaring and non-flaring active regions
Authors: Kilcik, A.; Yurchyshyn, V.; Sahin, S.; Sarp, V.; Obridko,
V.; Ozguc, A.; Rozelot, J. P.
2018MNRAS.477..293K Altcode:
According to the modified Zurich classification, sunspot groups are
classified into seven different classes (A, B, C, D, E, F and H) based
on their morphology and evolution. In this classification, classes
A and B, which are small groups, describe the beginning of sunspot
evolution, while classes D, E and F describe the large and evolved
groups. Class C describes the middle phase of sunspot evolution and
the class H describes the end of sunspot evolution. Here, we compare
the lifetime and temporal evolution of flaring and non-flaring active
regions (ARs), and the flaring effect on ARs in these groups in detail
for the last two solar cycles (1996 through 2016). Our main findings
are as follows: (i) Flaring sunspot groups have longer lifetimes
than non-flaring ones. (ii) Most of the class A, B and C flaring
ARs rapidly evolve to higher classes, while this is not applicable
for non-flaring ARs. More than 50 per cent of the flaring A, B and
C groups changed morphologically, while the remaining D, E, F and
H groups did not change remarkably after the flare activity. (iii)
75 per cent of all flaring sunspot groups are large and complex. (iv)
There is a significant increase in the sunspot group area in classes A,
B, C, D and H after flaring activity. In contrast, the sunspot group
area of classes E and F decreased. The sunspot counts of classes D, E
and F decreased as well, while classes A, B, C and H showed an increase.

---------------------------------------------------------
Title: Temporal and Periodic Variations of Sunspot Counts in Flaring
and Non-Flaring Active Regions
Authors: Kilcik, A.; Yurchyshyn, V.; Donmez, B.; Obridko, V. N.;
Ozguc, A.; Rozelot, J. P.
2018SoPh..293...63K Altcode: 2017arXiv170509065K
We analyzed temporal and periodic variations of sunspot counts (SSCs)
in flaring (C-, M-, or X-class flares), and non-flaring active regions
(ARs) for nearly three solar cycles (1986 through 2016). Our main
findings are as follows: i) temporal variations of monthly means of
the daily total SSCs in flaring and non-flaring ARs behave differently
during a solar cycle and the behavior varies from one cycle to another;
during Solar Cycle 23 temporal SSC profiles of non-flaring ARs are wider
than those of flaring ARs, while they are almost the same during Solar
Cycle 22 and the current Cycle 24. The SSC profiles show a multi-peak
structure and the second peak of flaring ARs dominates the current
Cycle 24, while the difference between peaks is less pronounced during
Solar Cycles 22 and 23. The first and second SSC peaks of non-flaring
ARs have comparable magnitude in the current solar cycle, while the
first peak is nearly absent in the case of the flaring ARs of the same
cycle. ii) Periodic variations observed in the SSCs profiles of flaring
and non-flaring ARs derived from the multi-taper method (MTM) spectrum
and wavelet scalograms are quite different as well, and they vary from
one solar cycle to another. The largest detected period in flaring
ARs is 113 ±1.6 days while we detected much longer periodicities (327
±13 , 312 ±11 , and 256 ±8 days) in the non-flaring AR profiles. No
meaningful periodicities were detected in the MTM spectrum of flaring
ARs exceeding 55 ±0.7 days during Solar Cycles 22 and 24, while a 113
±1.3 days period was detected in flaring ARs of Solar Cycle 23. For
the non-flaring ARs the largest detected period was only 31 ±0.2
days for Cycle 22 and 72 ±1.3 days for the current Cycle 24, while
the largest measured period was 327 ±13 days during Solar Cycle 23.

---------------------------------------------------------
Title: Some Statistical Properties of Magnetic Fields and Sunspots
Authors: Obridko, V. N.; Shelting, B. D.
2018RNAAS...2...40O Altcode: 2018RNAAS...2a..40O
No abstract at ADS

---------------------------------------------------------
Title: Some Features of the Variation of the Magnetic Field
Characteristics in the Umbra of Sunspots During Flares and Coronal
Mass Ejections
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Rudenko, G. V.; Obridko,
V. N.
2017Ge&Ae..57..835Z Altcode:
The observed variations of the magnetic properties of sunspots during
eruptive events (solar flares and coronal mass ejections (CMEs)) are
discussed. Variations of the magnetic field characteristics in the
umbra of the sunspots of active regions (ARs) recorded during eruptive
events on August 2, 2011, March 9, 2012, April 11, 2013, January 7,
2014, and June 18, 2015, are studied. The behavior of the maximum of
the total field strength B max, the minimum inclination
angle of the field lines to the radial direction from the center of the
Sun αmin (i.e., the inclination angle of the axis of the
magnetic tube from the sunspot umbra), and values of these parameters
B mean and αmean mean within the umbra are
analyzed. The main results of our investigation are discussed by the
example of the event on August 2, 2011, but, in general, the observed
features of the variation of magnetic field properties in AR sunspots
are similar for all of the considered eruptive events. It is shown
that, after the flare onset in six AR sunspots on August 2, 2011,
the behavior of the specified magnetic field parameters changes in
comparison with that observed before the flare onset.

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Title: Two populations of the solar magnetic field
Authors: Obridko, V. N.; Livshits, I. M.; Sokoloff, D. D.
2017MNRAS.472.2575O Altcode:
Dynamo theory suggests that there are two types of solar dynamo,
namely the conventional mean-field dynamo, which produces large-
and small-scale magnetic fields involved in the activity cycle,
and also the small-scale dynamo, which produces a cycle independent
small-scale magnetic field. The relative contribution of the two
mechanisms to solar magnetism remains a matter of scientific debate,
which includes the opinion that the contribution of the small-scale
dynamo is negligible. Here, we consider several tracers of magnetic
activity that separate cycle-dependent contributions to the background
solar magnetic field from those that are independent of the cycle. We
call background fields the magnetic fields outside active regions and
give further development of this concept. The main message of our paper
is that background fields include two relative separate populations. The
background fields with a strength up to 100 Mx cm-2 are very
poorly correlated with the sunspot numbers and vary little with the
phase of the cycle. In contrast, stronger magnetic fields demonstrate
pronounced cyclic behaviour. We discuss how this result can be included
in the above-mentioned concepts of solar dynamo studies.

---------------------------------------------------------
Title: The Sun and the Biosphere: the Paradoxes of 4 Billion Years
of Coexistence
Authors: Ragulskaya, M. V.; Obridko, V. N.
2017RRPRA..22..276R Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Comparison of Magnetic Properties and Shadow Area of Leading
and Trailing Spots with Different Asymmetries
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.; Rudenko,
V. G.
2017Ge&Ae..57..946Z Altcode:
The magnetic properties of the shadow of magnetic-related leading
and trailing spots (those connected by forces lines of magnetic
field, which are calculated from a field in potential approximation)
are studied in this work. The correlations are established between
individual characteristics of the field in the spot shadow and these
characteristics from the shadow area S for spot pairs, for which the
minimum angle between the measured vector of magnetic induction B in
the shadow of the leading (L) spot and positive normal to the solar
surface is lower than in the trailing (F) spot (αmin-L
&lt; αmin-F) and, vice versa, when αmin-L
&gt; αmin-F. It is shown that the αmin-L( S
L), αmin-F( S F), Bmax-L(
S L) and Bmax-F( S F) correlations
are similar behaviorally and quantitatively for two groups of spots
with different asymmetries of a magnetically connected field ( B
max-L, F is the maximum of magnetic induction in the shadow
of leading and trailing spots). The correlation between the average
angles within the spot shadow &lt;αL, F&gt; and the area
of the spot shadow S L, F and between the average value
of magnetic induction in the spot shadow &lt; B L, F&gt;
differ in two cases. In most studied spot pairs, the leading spot is
closer to the dividing line of polarity between the spots rather than
the trailing one.

---------------------------------------------------------
Title: On the nature of the magnetic field asymmetry in magnetically
coupled leading and following sunspots observed in active regions
with no eruptive events
Authors: Zagainova, Iu. S.; Fainshtein, V. G.; Rudenko, G. V.; Obridko,
V. N.
2017arXiv171108895Z Altcode:
In this study, we investigate magnetic properties of umbra of
magneto-conjugate leading and following sunspots, i.e. connected
through magnetic field lines. We established dependences between
individual sunspot umbra field characteristics, and between these
characteristics on the umbra area ($S$) separately for sunspot pairs,
for which the minimal angle between the umbra magnetic field line
of the leading ($L$) sunspot and the positive normal line to the
Sun surface is smaller, than that in the following ($F$) sunspot
($\alpha_{min-L}&lt;\alpha_{min-F}$; such sunspot pairs are the bulk)
and, on the contrary, when $\alpha_{min-L}&gt;\alpha_{min-F}$. The
$\alpha_{min-L}(S_L)$, $\alpha_{min-F}(S_F)$, $B_{max-L}(S_L)$
and $B_{max-F}(S_F)$ dependences are shown to have similar behavior
features, and are quantitatively close for two sunspot groups with
a different asymmetry of the sunspot magnetic field connecting them
(here, $B_{max-L,F}(S_L)$ is the magnetic induction maximum induction
in umbrae of the leading and the following sunspots). The dependence of
mean values of angles within umbra $&lt;\alpha_{L,F}&gt;$ on the sunspot
umbra area $S_{L,F}$ and on the mean value of magnetic induction in
umbra $&lt;B_{L,F}&gt;$ appeared different for two cases. Also, in the
bulk of the investigated sunspot pairs, the leading sunspot was shown
to appear closer to the polarity inversion line between the sunspots,
than the following one. This result and the conclusion that, in the
bulk of the investigated pairs of the magnetically conjugate sunspots,
$\alpha_{min-L}&lt;\alpha_{min-F}$ are closely coupled.

---------------------------------------------------------
Title: Meridional component of the large-scale magnetic field at
minimum and characteristics of the subsequent solar activity cycle
Authors: Obridko, V. N.; Shelting, B. D.
2017AstL...43..697O Altcode:
The polar magnetic field near the cycle minimum is known to correlate
with the height of the next sunspot maximum. There is reason to believe
that the hemispheric coupling can play an important role in forming
the next cycle. The meridional component of the large-scale magnetic
field can be one of the hemispheric coupling indices. For our analysis
we have used the reconstructed data on the large-scale magnetic field
over 1915-1986. We show that in several cycles not only the height but
also the general course of the cycle can be described in this way about
6 years in advance. This coupling has been confirmed by the currently
available data from 1976 to 2016, but the ratio of the meridional field
to the total absolute value of the field vector has turned out to be a
more promising parameter. In this paper it was calculated at a height
of ∼70 Mm above the photosphere. The date of the forthcoming minimum
is estimated using this parameter to be mid-2018; using the global field
as a forecast parameter gives a later date of the minimum, early 2020.

---------------------------------------------------------
Title: North-south asymmetry of solar activity as a superposition
of two realizations - the sign and absolute value
Authors: Badalyan, O. G.; Obridko, V. N.
2017A&A...603A.109B Altcode:
Context. Since the occurrence of north-south asymmetry (NSA) of
alternating sign may be determined by different mechanisms, the
frequency and amplitude characteristics of this phenomenon should be
considered separately. Aims: We propose a new approach to the
description of the NSA of solar activity. Methods: The asymmetry
defined as A = (N-S)/(N + S) (where N and S are, respectively, the
indices of activity of the northern and southern hemispheres) is treated
as a superposition of two functions: the sign of asymmetry (signature)
and its absolute value (modulus). This approach is applied to the
analysis of the NSA of sunspot group areas for the period 1874-2013. Results: We show that the sign of asymmetry provides information on
the behavior of the asymmetry. In particular, it displays quasi-periodic
variation with a period of 12 yr and quasi-biennial oscillations as the
asymmetry itself. The statistics of the so-called monochrome intervals
(long periods of positive or negative asymmetry) are considered and
it is shown that the distribution of these intervals is described by
the random distribution law. This means that the dynamo mechanisms
governing the cyclic variation of solar activity must involve random
processes. At the same time, the asymmetry modulus has completely
different statistical properties and is probably associated with
processes that determine the amplitude of the cycle. One can reliably
isolate an 11-yr cycle in the behavior of the asymmetry absolute value
shifted by half a period with respect to the Wolf numbers. It is shown
that the asymmetry modulus has a significant prognostic value: the
higher the maximum of the asymmetry modulus, the lower the following
Wolf number maximum. Conclusions: A fundamental nature of this
concept of NSA is discussed in the context of the general methodology
of cognizing the world. It is supposed that the proposed description
of the NSA will help clarify the nature of this phenomenon.

---------------------------------------------------------
Title: Comparison of the magnetic properties of leading and following
spots and the overlying ultraviolet emission
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.; Rudenko,
G. V.
2017ARep...61..533Z Altcode:
SDO/HMI and SDO/AIA data for the 24th solar-activity cycle are
analyzed using a quicker and more accurate method for resolving π
ambiguities in the transverse component of the photospheric magnetic
field, yielding new results and confirming some earlier results on the
magnetic properties of leading and following magnetically connected
spots and single spots. The minimum inclination of the field lines
to the positive normal to the solar surface α min within
umbrae is smaller in leading than in following spots in 78% of the
spot pairs considered; the same trend is found for the mean angle &lt;
α&gt; in 83% of the spot pairs. Positive correlations between the
α min values and the &lt; α&gt; values in leading and
following spots are also found. On average, in umbrae, the mean values
of &lt; B&gt;, the umbra area S, and the angles α min
and &lt; α&gt; decrease with growth in the maximum magnetic field B
max in both leading and following spots. The presence of
a positive correlation between B max and S is confirmed,
and a positive correlation between &lt; B&gt; and S in leading and
following spots has been found. Themagnetic properties of the umbrae of
magnetically connected pairs of spots are compared with the contrast
of the He II 304 emission above the umbrae, C 304. Spots
satisfying certain conditions display a positive correlation between
C 304- L and &lt; α L &gt; for the leading
(L) spots, and between C 304- L / C 304- F and
l L / l F , where l L ( l 
F ) are the lengths of the field lines connecting leading (L)
or following (F) spots from the corresponding spot umbrae to the apex
of the field line.

---------------------------------------------------------
Title: 22-year cycle of differential rotation of the solar corona
and the rule by Gnevyshev-Ohl
Authors: Badalyan, O. G.; Obridko, V. N.
2017MNRAS.466.4535B Altcode: 2017MNRAS.tmp..137B
The time variation of the parameters of differential rotation of the
solar corona is considered based on data on the coronal green-line
brightness. Separate analysis is performed for even and odd cycles. It
is shown that the equatorial rotation rate of the corona increases in
the epochs of minimum between the even and odd cycles and reaches its
minimum values between the odd and even cycles. Besides, it is found
that the differential rotation gradient in absolute value increases in
the even cycles. Both these factors may act to increase the amplitude
of the odd cycle compared to the preceding even one. Perhaps, this is
what explains the effect of Gnevyshev-Ohl.

---------------------------------------------------------
Title: Polar conic current sheets as sources and channels of energetic
particles in the high-latitude heliosphere
Authors: Khabarova, Olga; Malova, Helmi; Kislov, Roman; Zelenyi,
Lev; Obridko, Vladimir; Kharshiladze, Alexander; Tokumaru, Munetoshi;
Sokół, Justyna; Grzedzielski, Stan; Fujiki, Ken'ichi; Malandraki,
Olga
2017EGUGA..1918130K Altcode:
The existence of a large-scale magnetically separated conic region
inside the polar coronal hole has been predicted by the Fisk-Parker
hybrid heliospheric magnetic field model in the modification of Burger
and co-workers (Burger et al., ApJ, 2008). Recently, long-lived
conic (or cylindrical) current sheets (CCSs) have been found from
Ulysses observations at high heliolatitudes (Khabarova et al., ApJ,
2017). The characteristic scale of these structures is several times
lesser than the typical width of coronal holes, and the CCSs can
be observed at 2-3 AU for several months. CCS crossings in 1994 and
2007 are characterized by sharp decreases in the solar wind speed and
plasma beta typical for predicted profiles of CCSs. In 2007, a CCS
was detected directly over the South Pole and strongly highlighted
by the interaction with comet McNaught. The finding is confirmed by
restorations of solar coronal magnetic field lines that reveal the
occurrence of conic-like magnetic separators over the solar poles
both in 1994 and 2007. Interplanetary scintillation data analysis also
confirms the existence of long-lived low-speed regions surrounded by
the typical polar high-speed solar wind in solar minima. The occurrence
of long-lived CCSs in the high-latitude solar wind could shed light
on how energetic particles reach high latitudes. Energetic particle
enhancements up to tens MeV were observed by Ulysses at edges of CCSs
both in 1994 and 2007. In 1994 this effect was clearer, probably due to
technical reasons. Accelerated particles could be produced either by
magnetic reconnection at the edges of a CCS in the solar corona or in
the solar wind. We discuss the role of high-latitude CCSs in propagation
of energetic particles in the heliosphere and revisit previous studies
of energetic particle enhancements at high heliolatitudes. We also
suggest that the existence of a CCS can modify the distribution of
the solar wind as a function of heliolatitude and consequently impact
ionization rates of heliospheric particles such as neutral interstellar
gas atoms, pick-up ions or energetic neutral atoms This project has
received funding from the European Union's Horizon 2020 research and
innovation programme under grant agreement No 637324 and the Russian
Foundation for Basic Research under grant agreements No 17-02-00300
&amp; No 17-02-01328. O. Khabarova, H. Malova, R. Kislov, L. Zelenyi,
V. Obridko, A. Kharshiladze, M. Tokumaru , J. Sokół, S. Grzedzielski,
K. Fujiki, 2017, the Astrophysical Journal, under review

---------------------------------------------------------
Title: On the history of the solar wind discovery
Authors: Obridko, V. N.; Vaisberg, O. L.
2017SoSyR..51..165O Altcode:
The discovery of the solar wind has been an outstanding achievement
in heliophysics and space physics. The solar wind plays a crucial role
in the processes taking place in the Solar System. In recent decades,
it has been recognized as the main factor that controls the terrestrial
effects of space weather. The solar wind is an unusual plasma laboratory
of giant scale with a fantastic diversity of parameters and operating
modes, and devoid of influence from the walls of laboratory plasma
systems. It is also the only kind of stellar wind accessible for
direct study. The history of this discovery is quite dramatic. Like
many remarkable discoveries, it had several predecessors. However,
the honor of a discovery usually belongs to a scientist who was able to
more fully explain the phenomenon. Such a man is deservedly considered
the US theorist Eugene Parker, who discovered the solar wind, as we
know it today, almost "with the point of his pen". In 2017, we will
celebrate the 90th anniversary birthday of Eugene Parker.

---------------------------------------------------------
Title: Intermittency of the Solar Magnetic Field and Solar Magnetic
Activity Cycle
Authors: Shibalova, A. S.; Obridko, V. N.; Sokoloff, D. D.
2017SoPh..292...44S Altcode:
Small-scale solar magnetic fields demonstrate features of fractal
intermittent behavior, which requires quantification. For this purpose
we investigate how the observational estimate of the solar magnetic
flux density B depends on resolution D in order to obtain the scaling
lnBD=−k lnD +a in a reasonably wide range. The quantity k
demonstrates cyclic variations typical of a solar activity cycle. In
addition, k depends on the magnetic flux density, i.e. the ratio of
the magnetic flux to the area over which the flux is calculated, at
a given instant. The quantity a demonstrates some cyclic variation,
but it is much weaker than in the case of k . The scaling obtained
generalizes previous scalings found for the particular cycle phases. The
scaling is typical of fractal structures. In our opinion, the results
obtained trace small-scale action in the solar convective zone and
its coexistence with the conventional large-scale solar dynamo based
on differential rotation and mirror-asymmetric convection.

---------------------------------------------------------
Title: High-latitude Conic Current Sheets in the Solar Wind
Authors: Khabarova, Olga V.; Malova, Helmi V.; Kislov, Roman A.;
Zelenyi, Lev M.; Obridko, Vladimir N.; Kharshiladze, Alexander F.;
Tokumaru, Munetoshi; Sokół, Justyna M.; Grzedzielski, Stan; Fujiki,
Ken'ichi
2017ApJ...836..108K Altcode:
We provide observational evidence for the existence of large-scale
cylindrical (or conic-like) current sheets (CCSs) at high
heliolatitudes. Long-lived CCSs were detected by Ulysses during its
passages over the South Solar Pole in 1994 and 2007. The characteristic
scale of these tornado-like structures is several times less than a
typical width of coronal holes within which the CCSs are observed. CCS
crossings are characterized by a dramatic decrease in the solar wind
speed and plasma beta typical for predicted profiles of CCSs. Ulysses
crossed the same CCS at different heliolatitudes at 2-3 au several times
in 1994, as the CCS was declined from the rotation axis and corotated
with the Sun. In 2007, a CCS was detected directly over the South Pole,
and its structure was strongly highlighted by the interaction with
comet McNaught. Restorations of solar coronal magnetic field lines
reveal the occurrence of conic-like magnetic separators over the
solar poles in both 1994 and 2007. Such separators exist only during
solar minima. Interplanetary scintillation data analysis confirms the
presence of long-lived low-speed regions surrounded by the typical
polar high-speed solar wind in solar minima. Energetic particle flux
enhancements up to several MeV/nuc are observed at edges of the CCSs. We
built simple MHD models of a CCS to illustrate its key features. The
CCSs may be formed as a result of nonaxiality of the solar rotation axis
and magnetic axis, as predicted by the Fisk-Parker hybrid heliospheric
magnetic field model in the modification of Burger and coworkers.

---------------------------------------------------------
Title: Magnetic field variations in the umbra of single sunspots
during their passage across the solar disk
Authors: Zagainova, Iu. S.; Fainshtein, V. G.; Obridko, V. N.; Rudenko,
G. V.
2016Ge&Ae..56.1015Z Altcode:
Temporal variations of the maximum ( B max) and average
(&lt; B&gt;) magnetic inductions, minimum ( α min) and
average (&lt; α&gt;) inclination angles of the field lines to the
radial direction from the center of the Sun, and areas of the sunspot
umbra S in the umbra of single sunspots during their passage across the
solar disk are investigated. The variation of the properties of single
sunspots has been considered at different stages of their existence,
i.e., during formation, the "quiet" period, and the disappearance
stage. It has been found that, for the majority of the selected single
sunspots, there is a positive correlation between B max
and S and between and S defined at different times during the passage
of sunspots across the solar disk. It is shown in this case that the
nature of the dependence between the parameters α min
and B max, α min and S, as well as between
&lt; α&gt; and &lt; B&gt;, &lt; α&gt; and S, can vary from sunspot
to sunspot, but for many sunspots the inclination angle of the field
lines decreases on average with the growth of the sunspot umbra area
and the field strength.

---------------------------------------------------------
Title: The Sun and heliosphere explorer - the Interhelioprobe mission
Authors: Kuznetsov, V. D.; Zelenyi, L. M.; Zimovets, I. V.;
Anufreychik, K.; Bezrukikh, V.; Chulkov, I. V.; Konovalov, A. A.;
Kotova, G. A.; Kovrazhkin, R. A.; Moiseenko, D.; Petrukovich,
A. A.; Remizov, A.; Shestakov, A.; Skalsky, A.; Vaisberg, O. L.;
Verigin, M. I.; Zhuravlev, R. N.; Andreevskyi, S. E.; Dokukin, V. S.;
Fomichev, V. V.; Lebedev, N. I.; Obridko, V. N.; Polyanskyi, V. P.;
Styazhkin, V. A.; Rudenchik, E. A.; Sinelnikov, V. M.; Zhugzhda,
Yu. D.; Ryzhenko, A. P.; Ivanov, A. V.; Simonov, A. V.; Dobrovolskyi,
V. S.; Konstantinov, M. S.; Kuzin, S. V.; Bogachev, S. A.; Kholodilov,
A. A.; Kirichenko, A. S.; Lavrentiev, E. N.; Pertsov, A. A.; Reva,
A. A.; Shestov, S. V.; Ulyanov, A. S.; Panasyuk, M. I.; Iyudin,
A. F.; Svertilov, S. I.; Bogomolov, V. V.; Galkin, V. I.; Marjin,
B. V.; Morozov, O. V.; Osedlo, V. I.; Rubinshtein, I. A.; Scherbovsky,
B. Ya.; Tulupov, V. I.; Kotov, Yu. D.; Yurov, V. N.; Glyanenko, A. S.;
Kochemasov, A. V.; Lupar, E. E.; Rubtsov, I. V.; Trofimov, Yu. A.;
Tyshkevich, V. G.; Ulin, S. E.; Novikov, A. S.; Dmitrenko, V. V.;
Grachev, V. M.; Stekhanov, V. N.; Vlasik, K. F.; Uteshev, Z. M.;
Chernysheva, I. V.; Shustov, A. E.; Petrenko, D. V.; Aptekar, R. L.;
Dergachev, V. A.; Golenetskii, S. V.; Gribovskyi, K. S.; Frederiks,
D. D.; Kruglov, E. M.; Lazutkov, V. P.; Levedev, V. V.; Oleinik,
F. P.; Palshin, V. D.; Repin, A. I.; Savchenko, M. I.; Skorodumov,
D. V.; Svinkin, D. S.; Tsvetkova, A. S.; Ulanov, M. V.; Kozhevatov,
I. E.; Sylwester, J.; Siarkowski, M.; Bąkała, J.; Szaforz, Ż.;
Kowaliński, M.; Dudnik, O. V.; Lavraud, B.; Hruška, F.; Kolmasova,
I.; Santolik, O.; Šimůnek, J.; Truhlík, V.; Auster, H. -U.;
Hilchenbach, M.; Venedictov, Yu.; Berghofer, G.
2016Ge&Ae..56..781K Altcode:
The Interhelioprobe mission aims to investigate the inner heliosphere
and the Sun from close distances (up to 0.3 AU) and from out of the
ecliptic plane (up to 30°). In this paper we present the relevance of
the mission and its main scientific objectives, describe the scientific
payload, ballistic scenario and orbits of the spacecraft. Possibilities
of scientific cooperation with other solar and heliospheric space
missions are also mentioned.

---------------------------------------------------------
Title: Properties of solar activity and ionosphere for solar cycle 25
Authors: Deminov, M. G.; Nepomnyashchaya, E. V.; Obridko, V. N.
2016Ge&Ae..56..742D Altcode:
Based on the known forecast of solar cycle 25 amplitude (
Rz max ≈ 50), the first assessments of the shape and
amplitude of this cycle in the index of solar activity F10.7 (the
magnitude of solar radio flux at the 10.7 cm wavelength) are given. It
has been found that ( F10.7)max ≈ 115, which means that
it is the lowest solar cycle ever encountered in the history of regular
ionospheric measurements. For this reason, many ionospheric parameters
for cycle 25, including the F2-layer peak height and critical frequency
( hmF2 and foF2), will be extremely low. For example, at middle
latitudes, typical foF2 values will not exceed 8-10 MHz, which makes
ionospheric heating ineffective in the area of upper hybrid resonance
at frequencies higher than 10 MHz. The density of the atmosphere will
also be extremely low, which significantly extends the lifetime of
low-orbit satellites. The probability of F-spread will be increased,
especially during night hours.

---------------------------------------------------------
Title: The phase shift between the hemispheres in the solar activity
cycle
Authors: Shibalova, A. S.; Obridko, V. N.; Sokoloff, D. D.
2016ARep...60..949S Altcode:
The shift between the solar activity cycles in the northern and
southern hemispheres of the Sun is studied using data on sunspot number
and area. The data obtained are compared with archival information
on episodes of appreciable solar-cycle asymmetry. The small phase
shift between recent activity cycles in the northern and southern
solar hemispheres differs considerably from the shift for episodes of
appreciable deviations from dipolar symmetry in the sunspot distribution
detected with various degrees of confidence in archival astronomical
data from the 17th-19th centuries. The current time shift between the
hemispheres is insignificant, about 6-7 months. This shift has changed
its sign twice in recent solar history; this probably corresponds to
more or less periodic variations with a timescale close to the duration
of the Gleissberg cycle.

---------------------------------------------------------
Title: On the negative correlation between solar activity and solar
rotation rate
Authors: Obridko, V. N.; Shelting, B. D.
2016AstL...42..631O Altcode:
An increase in solar activity is shown to be accompanied by a decrease
in solar rotation rate. This effect has been established from various
indices; it manifests itself as cyclic and secular variations in the
global magnetic field, in the observations of the magnetic field of
the Sun as a star, and in the observations of the solar corona. Some
possible explanations of this effect are discussed.

---------------------------------------------------------
Title: A cylindrical current sheet over the South solar pole observed
by Ulysses
Authors: Khabarova, Olga; Kislov, Roman; Malova, Helmi; Obridko,
Vladimir
2016EGUGA..1818076K Altcode:
We provide the first evidence for the existence of a quasi-stable
cylindrical current sheet over the South solar pole as observed by
Ulysses in 2006, near the solar minimum, when it reached maximal
heliolatitude of 79.7 degrees at 2.4 AU. It took place inside a fast
speed stream from the coronal hole, and the tube was presumably crossed
rather far from the center within two degrees of heliolatitude and ~10
degrees of heliolongitude. During the spacecraft passage throughout the
structure, the solar wind velocity was approximately twice as little,
the solar wind density was 20 times lower than the surrounded plasma
values, but the temperature was twice as large in the point closest to
the pole. The interplanetary magnetic field (IMF) strongly decreased
due to sharp variations in the IMF radial component (RTN) that changed
its sign twice, but other components did not show changes out of usual
stochastic behavior. Both the behavior of the IMF, rotation of the
plasma flow direction and other features indicate the occurrence of
cylindrical current sheet. We discuss its solar origin and present
modeling that can explain the observations.

---------------------------------------------------------
Title: Long-period geomagnetic pulsations as solar flare precursors
Authors: Barkhatov, N. A.; Obridko, V. N.; Revunov, S. E.; Snegirev,
S. D.; Shadrukov, D. V.; Sheiner, O. A.
2016Ge&Ae..56..249B Altcode:
We compare long-period pulsations of the horizontal component of the
geomagnetic field at intervals that precede extreme solar flares. To
this end, we use the wavelet-skeleton technique to process the
geomagnetic field disturbances recorded at magnetic stations over a
wide geographical range. The synchronization times of wavelet-skeleton
spectral distributions of long-period pulsations of geomagnetic
oscillations over all magnetic stations are shown as normalized
histograms. A few days before an intense solar flare, the histograms
show extremes. This means that these extremes can be regarded as flare
precursors. The same technique is used to analyze the parameters of
near-Earth space. The histograms obtained in this case are free of
the aforementioned extrema and, therefore, cannot point to an upcoming
flare. The goal of this study is to construct a correlation-spectral
method for the short-term prediction of solar flare activity.

---------------------------------------------------------
Title: What causes geomagnetic activity during sunspot minimum?
Authors: Kirov, B.; Asenovski, S.; Georgieva, K.; Obridko, V. N.
2015Ge&Ae..55.1033K Altcode: 2014arXiv1412.0886K
It is well known that the main drivers of geomagnetic disturbances
are coronal mass ejections whose number and intensity are maximum in
sunspot maximum, and high speed solar wind streams from low latitude
solar coronal holes which maximize during sunspot declining phase. But
even during sunspot minimum periods when there are no coronal mass
ejections and no low latitude solar coronal holes, there is some "floor"
below which geomagnetic activity never falls. Moreover, this floor
changes from cycle to cycle. Here we analyze the factors determining
geomagnetic activity during sunspot minimum. It is generally accepted
that the main factor is the thickness of the heliospheric current
sheet on which the portion of time depends which the Earth spends in
the slow and dense heliospheric current sheet compared to the portion
of time it spends in the fast solar wind from superradially expanding
polar coronal holes. We find, however, that though the time with
fast solar wind has been increasing in the last four sunspot minima,
the geomagnetic activity in minima has been decreasing. The reason is
that the parameters of the fast solar wind from solar coronal holes
change from minimum to minimum, and the most important parameter for
the fast solar wind's geoeffectivity—its dynamic pressure—has been
decreasing since cycle 21. Additionally, we find that the parameters
of the slow solar wind from the heliospheric current sheet which is
an important driver of geomagnetic activity in sunspot minimum also
change from cycle to cycle, and its magnetic field, velocity and
dynamic pressure have been decreasing during the last four minima.

---------------------------------------------------------
Title: Leading and following sunspots: their magnetic properties
and ultra-violet emission above them
Authors: Zagainova, Iu. S.; Fainshtein, V. G.; Obridko, V. N.
2015arXiv151107229Z Altcode:
Using SDO/HMI and SDO/AIA data for sunspot groups of the 24th solar
cycle, we analyzed magnetic properties and He II 304 emission in leading
and following sunspots separately. Simultaneous examination of umbral
magnetic properties and atmospheric characteristics above the umbrae
draws on average differences in He II 304 contrast over the umbrae
of leading and following spots we discovered earlier for solar cycle
23 sunspot groups based on SOHO data as well as on the hypothetical
relationship between contrast asymmetry and magnetic field asymmetry
in umbrae. We use a more accurate and faster algorithm for solving the
pi-uncertainty problem of the transverse magnetic field direction in
this research producing new results on differences in magnetic field
properties between magneto-conjugated leaders and followers. We found
that, in ~78% of the cases, the minimum (over the umbra area) angle
between the magnetic field line and the normal to the solar surface,
a_min, is smaller in the leading spots, so the magnetic field there is
more vertical than that in the counterpart following spot. It was also
found that umbral area-averaged angle &lt;a&gt; in ~83% of the spot
groups examined is smaller in the leader compared to the follower and
the maximum and mean magnetic flux densities inside the umbra depend
on the umbral area.

---------------------------------------------------------
Title: The relative role of space weather factors in Chizhevsky
Velkhover effect
Authors: Gromozova, E.; Rudenchik, E.; Ragulskaya, M.; Obridko, V.;
Hramova, E.
2015simi.conf...96G Altcode:
The Astrobiological Chizhevsky–Velkhover effect occupies a special
place among biological effects, concerned with solar activity. It's
about the color change of structure elements (volyutin granules) of
bacterium sells at staining by methylene blue solution (metachromasia
reaction). Today the volyutin granules, consisting of inorganic
polyphosphate, were observed at procaryotes, lower eukaryotes, at
protozoa, and as phosphatic pellets in platelets of higher organisms
(including human). According to the discoverers, volyutin granules
color change depends on solar activity. But since 1934 new data about
structure of solar-earth relations were observed, and the solar dynamics
changed. Cosmic weather factors having the dominating influence on
etalon sell structures in 2000 – 2013 are discussed in the report.

---------------------------------------------------------
Title: The Upper Limit of Sunspot Activity as Observed over a Long
Time Interval
Authors: Nagovitsyn, Yu. A.; Obridko, V. N.; Kuleshova, A. I.
2015SoPh..290.1285N Altcode: 2015SoPh..tmp...23N
After analyzing the observational manifestations of the α- and
ω-effects of the dynamo theory and using the modified Waldmeier rule,
we show that the annual mean Wolf numbers at the maximum of the 11-year
cycle that are likely to occur a time interval of 104 years
have an upper limit amounting approximately to WEXTR∼230 -
240. Similar values were also obtained using the results by Usoskin et
al. (2014, Astron. Astrophys. 562, L10), who considered the probability
of various activity levels by reconstructing the variations of
solar activity over three thousand years. As an additional result,
the predicted maximum of Cycle 24 is refined and is shown to be
WM=72 - 132 with a 95 % confidence.

---------------------------------------------------------
Title: A comparative analysis of the properties of the magnetic
fields in leading and trailing sunspots
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Rudenko, G. V.; Obridko,
V. N.
2015ARep...59..156Z Altcode:
Pairs of leading and trailing sunspots whose umbrae are joined by
magnetic-field lines have been selected based on calculations using
SOLIS magnetic-field data in a potential approximation and the B 
d technique of Rudenko, together with SDO data for 2010-2013. The
shape of the field lines reflects to some extent the shape of the
magnetic tube connecting the leading and trailing spots. The minimum
angle between the field lines and the radial direction a min,
the maximum magnetic field B max, the length of the field
line from the leading spot to the apex, where the radial component of
the field is zero, L l , and the length of the field line
from the apex to its eastern base L f are determined
in the umbrae of all the selected sunspots. In ∼81% of cases, a
min is smaller in the leading spot than in the trailing
spot. For such sunspots, there is a positive correlation between
these angles in the leading and trailing spots. The dependences of a
min on the areas of the umbrae in the leading and trailing
spots are different. There is a weak negative correlation between
a min and B max. In other words, on average,
the field lines are closer to radial in magnetic tubes forming the
umbrae of both leading and trailing spots with stronger fields at the
photospheric level. In ∼60-65% of cases, the section of the field
adjacent to the leading spot L l is shorter than L 
f . Similar results are obtained for large single spots.

---------------------------------------------------------
Title: Comparison of the properties of leading and trailing sunspots
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.
2015Ge&Ae..55...13Z Altcode:
The magnetic properties of leading and trailing sunspots were compared
based on SDO/HMI and SDO/AIA data with a high spatial resolution for
the growth phase and maximum of cycle 24. The properties of the solar
atmosphere above sunspots are also discussed independently for both of
these sunspot types. It was shown that the contrast in the He II 304 (
C 304) line above the umbra of leading and single sunspots
is on average smaller than such a contrast above the umbra of trailing
sunspots and on average weakly depends on the umbra area for both
C 304 sunspot types. It was established that the minimal
angle between the field direction and the normal to the solar surface
at the field measurement site is smaller in leading sunspots than in
trailing ones (αmin - ls &lt; αmin - fs )
in 84% of the considered magnetically connected "leading-trailing"
sunspot pairs, and a positive correlation exists between angles
αmin - ls and αmin - fs . It was found that
the C 304 contrast increases with decreasing αmin -
ls, fs for leading and trailing sunspots, and the C 304
- ls / C 304 - fs ratio on average decreases with
increasing αmin - ls /αmin - fs ratio. The
dependences of the maximal and average magnetic induction values in an
umbra on the umbra area were constructed for the first time and compared
independently for leading and trailing sunspots. It was concluded that
the maximal and average magnetic field values do not vanish when the
umbra area decreases to very small values. In all cases the magnetic
field in leading and single sunspots is larger than in trailing ones.

---------------------------------------------------------
Title: Coronal Holes in Global Complexes of Activity
Authors: Obridko, Vladimir N.; Shelting, Bertha D.
2015AdAst2015E...7O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Role of the large-scale solar magnetic field structure in
the global organization of solar activity
Authors: Ivanov, E. V.; Obridko, V. N.
2014Ge&Ae..54..996I Altcode:
The relation of the large-scale solar magnetic field structure to
the most pronounced manifestations of solar activity (filaments,
active regions, sunspots, coronal mass ejections, and coronal holes)
has been studied.

---------------------------------------------------------
Title: Cyclic and secular variations sunspot groups with various
scales
Authors: Obridko, V. N.; Badalyan, O. G.
2014ARep...58..936O Altcode:
Data from the Greenwich Catalog and its NOAA-USEF extension are used to
analyze the spot-formation activity on the Sun separately for small (
S &lt; 100 msh), medium (100 &lt; S &lt; 500 msh), and large ( S &gt;
500 msh) sunspot groups. The relationship between the numbers of groups
with various areas changes with time. This is determined primarily
by numerous small-area groups. Over nearly 150 years, periods have
been observed when the relative number of large groups has increased
(Cycles 18 and 19), as well as extensive periodswhen the number of
small groups has grown. As a rule, the latter correspond to low activity
cycles. The observed relations indicate the possible interaction of two
independent mechanisms in the spot-formation activity of the Sun. A
deep dynamo controls the variations of the number of small spots,
while the formation of large spots is determined by processes in
sub-surface layers.

---------------------------------------------------------
Title: North-South Asymmetry in the Distribution of Solar Background
Magnetic Field
Authors: Obridko, V. N.; Chertoprud, V. E.; Kuzanyan, K. M.
2014SoPh..289.2867O Altcode: 2014SoPh..tmp...58O
The aim of this article is to investigate how the background magnetic
field of the Sun behaves in different hemispheres. We used SOHO/MDI data
obtained during a period of eight years from 2003 to 2011 to analyze the
intensity distribution of the background magnetic field over the solar
surface. We find that the background fields of both polarities (signs)
are more intense in the southern than in the northern hemisphere. Mixed
polarities are observed in the vicinity of the equator. In addition to
the main field, a weaker field of opposite polarity is always present
in the polar regions. In the declining phase of the cycle, the main
field dominates, but at the minimum and in the rising phase of the
cycle, it is gradually replaced by the growing stronger secondary field.

---------------------------------------------------------
Title: Cosmic ray modulation during the solar activity growth phase
of cycle 24
Authors: Gushchina, R. T.; Belov, A. V.; Eroshenko, E. A.; Obridko,
V. N.; Paouris, E.; Shelting, B. D.
2014Ge&Ae..54..430G Altcode:
Recent years allowed us to study long-term variations in the cosmic
ray (CR) intensity at an unusually deep solar activity (SA) minimum
between cycles 23 and 24 and during the SA growth phase in cycle 24,
which was the cycle when SA was the lowest for the epoch of regular
ground-based CR observations since 1951. The intensity maximum, the
value of which depends on the particle energy, was observed in CR
variations during the period of an unusually prolonged SA minimum: the
CR density during the aformentioned period (2009) is higher than this
density at previous CR maxima in cycles 19-23 for low-energy particles
(observed on spacecraft and in the stratosphere) and medium-energy
particles (observed with neutron monitors). After 2009 CR modulation
at the SA growth phase was much weaker over three years (2010-2012)
than during the corresponding SA growth periods in the previous
cycles. The possible causes of this anomaly in CR variations, which
are related to the CR residual modulation value at a minimum between
cycles 23 and 24 and to variations in SA characteristics during this
period, were examined. The contribution of different solar magnetic
field characteristics and indices, taking into account sporadic solar
activity, has been estimated.

---------------------------------------------------------
Title: Comparative Characteristics of the Leading and Following
Sunspots
Authors: Zagainova, Yu. S.; Fainshtein, V. G.; Obridko, V. N.
2014ATsir1612....1Z Altcode:
Magnetic characteristics of the leading and following sunspots
are compared using SDO/HMI and SDO/AIA high-resolution data, and
the properties of the solar atmosphere over sunspots are discussed
separately for each category of sunspots.

---------------------------------------------------------
Title: Global Complexes of Activity
Authors: Obridko, V. N.; Shelting, B. D.
2014simi.conf....4O Altcode:
A new concept of Global Complexes of Activity's on the Sun is presented,
which brings together objects associated with both global and local
fields in a single framework. Activity complexes have traditionally
been identified purely from observations of active regions. We show
here that a global complex also includes coronal holes and active
regions. Our analysis is based on a large dataset on magnetic fields on
various scales, SOHO/MDI observations of active regions and magnetic
fields, and UV observations of coronal holes. It is shown that the
evolution of coronal holes and active regions are parts of a single
process. The relationships between the fields of different scales
during the generation of the cycle is discussed.

---------------------------------------------------------
Title: Cosmic factors of evolution of biosphere and geosphere. (review
of the Interdisciplinary colloquium, May 21-23)
Authors: Obridko, V. N.
2014simi.conf...25O Altcode:
Main topics. Connection to the SCOSTEP international program
VarSITI. The young Sun: paradoxes and hypotheses. A review of ideas
of life origin: from ancient times to the present day. The early
stages of life evolution: archaeon, early proterozoic. Evolution
of biosphere. The role of climate-ecosystems interaction in climate
response to exterior impact. Geomagnetic reversal, its properties,
causes, possible impact on biosphere. Cosmic rays as a factor of
biosphere evolution, An estimate of the extreme energy of flares from
the theoretical point of view. Estimation of the maximal height of solar
cycle. The Maunder Minimum, its main characteristics and hypotheses
of its origin. Live organism adjustment to cosmic factors impact:
problems and prospective research.

---------------------------------------------------------
Title: The Relative Umbral Area in Spot Groups as an Index of Cyclic
Variation of Solar Activity
Authors: Bludova, N. G.; Obridko, V. N.; Badalyan, O. G.
2014SoPh..289.1013B Altcode:
The Greenwich series of data was used to study the ratio [q] of the
total umbra area to the total area of the sunspot group (for brevity
"relative umbral area") for the period 1874 - 1976. It was revealed
that the annual mean value of q varied in time from 0.15 to 0.28 and
reached its maximum in the early 1930s. The dependence of q on the
sunspot group area [S] was considered to show that the smallest groups,
of area less than 100 m.v.h. (millionths of the visible hemisphere),
contributed most significantly to the temporal variation of q. In
contrast to the earlier results, the dependence obtained proved to be
rather complicated. The coefficients of the linear expansion q(S) are
themselves dependent on the sunspot-group area and time [t]; i.e. the
relation of q to both S and t is nonlinear. Only in sunspot groups
with a large area does dependence disappear, and q becomes constant,
equal to 0.18. This is the value given in textbooks. The relations
obtained show that the relive umbral area and the relative number of
small groups are important parameters of the secular variation of solar
activity. In particular, they may account for variations in the mean
magnetic field in active regions, the complexity of a group according
to the magnetic classification, the flare activity of a sunspot group,
and its geophysical impact. It is conjectured that the parameter q
describes the time-varying relative contribution from the interior
and subsurface dynamo mechanisms.

---------------------------------------------------------
Title: Coronal holes and global complexes of activity
Authors: Obridko, Vladimir; Shelting, Bertha
2014cosp...40E2335O Altcode:
A new concept of the “Global Complexes of Activity” is presented,
which brings together the objects of both global and local fields. For
a long time, the complexes of activity were traditionally identified
only from observations of active regions. In this paper we show that
a global complex includes also coronal holes and active regions. The
analysis is based on a large set of data on magnetic fields of various
scales, SOHO/MDI observations of active regions and magnetic fields,
and UV observations of coronal holes. It is shown that the evolution
of coronal holes and active regions is a single process. Discussed is
the relationship between the fields of different scales in the process
of cycle generation

---------------------------------------------------------
Title: Transport of particles in the low- and high-energy solar wind
from the Sun to the Jupiter orbit
Authors: Khabarova, Olga; Obridko, Vladimir; Zharkova, Valentina
2014cosp...40E1456K Altcode:
In this report a comparison between the low- and high-energy solar wind
as seen from the multi-satellite observations is presented combined
with some effects of the large-scale structure interplanetary magnetic
field (IMF) on particle transport in the inner heliosphere. We will
present a comparison of the low-energy solar wind near the ecliptic
plane with those at high latitudes, at least up, to the Jupiter’s
orbit. The behaviour of solar wind particles in the low-energy range
up to 10 keV is determined by the solar wind expansion from the Sun,
and strongly depends on the quasi-stationary distribution of the
interplanetary magnetic field (IMF). At the same time, the origin and
dynamics of high-energy solar particles (with energies &gt;10 keV) at
heliocentric distances up to 1 AU are not significantly impacted by
this quasi-stationary interplanetary magnetic field. We explore the
contributions to the solar wind of impulsive SEP events from flares
in comparison with gradual SEP events, which can fill a big part of
the inner heliosphere. We will argue that transport of particles
through the heliosphere in the gradual SEP events can be affected
by the IMF variations caused by either small-scale processes like
magnetic turbulence often present in the interplanetary space or by a
deviation of the IMF from the classic model predictions. Observations
show that a decrease of the IMF radial component with distance has a
slope of -5/3 instead of -2 predicted by Parker’s model. We explore
a few possible reasons for this deviations and their impact on the
characteristics of the solar wind particles.

---------------------------------------------------------
Title: What causes geomagnetic activity during sunspot minimum?
Authors: Kirov, Boian; Obridko, Vladimir; Asenovski, Simeon
2014cosp...40E1502K Altcode:
Since the beginning of the geomagnetic measurements, the variations
in the geomagnetic field have been related to solar activity. It
is now known that big sporadic (non-recurrent) geomagnetic storms
are caused by coronal mass ejections. The coronal mass ejections are
related to the solar toroidal field whose manifestation are sunspots,
so during sunspot maximum there is also a maximum in geomagnetic
activity. Another source of geomagnetic activity are the coronal holes -
open unipolar magnetic field areas from which the high speed solar wind
emanates. Disturbances caused by high speed solar wind are maximum
during the sunspots declining phase, which leads to two geomagnetic
activity maxima in the 11-year sunspot cycle. In sunspot minimum, even
during long periods without sunspots and without low-latitude coronal
holes, geomagnetic disturbances are still observed. In the present
work we analyze the geomagnetic activity during sunspot minimum,
its sources and the reasons for its cyclic variations.

---------------------------------------------------------
Title: Solar activity over different timescales
Authors: Obridko, Vladimir; Nagovitsyn, Yuri
2014cosp...40E2334O Altcode:
The report deals with the “General History of the Sun” (multi-scale
description of the long-term behavior of solar activity): the
possibility of reconstruction. Time scales: • 100-150 years - the
Solar Service. • 400 - instrumental observations. • 1000-2000 years
- indirect data (polar auroras, sunspots seen with the naked eye). •
Over-millennial scale (Holocene) -14C (10Be) Overview and comparison
of data sets. General approaches to the problem of reconstruction of
solar activity indices on a large timescale. North-South asymmetry of
the sunspot formation activity. 200-year cycle over the “evolution
timescales”.The relative contribution of the large-scale and
low-latitude. components of the solar magnetic field to the general
geomagnetic activity. “Large-scale” and low-latitude sources of
geomagnetic disturbances.

---------------------------------------------------------
Title: Large-scale properties of the solar wind in the inner
heliosphere
Authors: Khabarova, Olga; Obridko, Vladimir; Zharkova, Valentina;
Veselov, Mikhail
2014cosp...40E1457K Altcode:
Since the solar wind phenomenon has been revealed and confirmed, one of
the most intriguing problems was to understand processes in the solar
atmosphere and their relation with the solar wind characteristics
at different distances from the Sun. Analysis of multi-spacecraft
measurements of plasma parameters and the interplanetary magnetic
field provides us with knowledge about the heliosphere from global
to small scales. Comparisons of observations with models, describing
small-scale processes, usually give more positive results than in
the case of models comparison with the solar wind properties at the
scales larger than several proton gyroradii. For example, Parker-like
models face with big problems in their attempts to predict the solar
wind plasma and, especially, the behaviour of the interplanetary
magnetic field. Observations show that the radial component of the
interplanetary magnetic field depends on heliolatitude and radially
decreases with a slope of -5/3 instead of the predicted slope of
-2 (Khabarova, Obridko, ApJ, 2012; Khabarova, Astronomy Reports,
2013). This may be determined by small-scale processes occurring
in some vicinity of the heliospheric current sheet and related to
the magnetic reconnection (Zharkova, Khabarova, ApJ, 2012). In this
report we present results of data analysis of eight spacecraft to study
variations of plasma, the electric and magnetic field with distance
and heliolatitude. begin{enumerate} Zharkova V., Khabarova O.,
Particle Acceleration in the Reconnecting Heliospheric Current Sheet:
Solar Wind Data Versus 3D PIC Simulations, Astrophysical Journal,
2012, V.752, 1, 35 doi:10.1088/0004-637X/752/1/35 begin{enumerate}
Khabarova Olga, and Obridko Vladimir, Puzzles of the Interplanetary
Magnetic Field in the Inner Heliosphere, 2012, Astrophysical Journal,
761, 2, 82, doi:10.1088/0004-637X/761/2/82 begin{enumerate} Khabarova
Olga V., The interplanetary magnetic field: radial and latitudinal
dependences. Astronomy Reports, 2013, Vol. 57, No. 11, pp. 844-859,
DOI: 10.1134/S1063772913110024

---------------------------------------------------------
Title: Long-term variations of geomagnetic activity and their
solar sources
Authors: Kirov, B.; Obridko, V. N.; Georgieva, K.; Nepomnyashtaya,
E. V.; Shelting, B. D.
2013Ge&Ae..53..813K Altcode: 2013arXiv1307.7960K
Geomagnetic activity in each phase of the solar cycle consists of
3 parts: (1) a "floor" below which the geomagnetic activity cannot
fall even in the absence of sunspots, related to moderate graduate
commencement storms; (2) sunspot-related activity due to sudden
commencement storms caused by coronal mass ejections; (3) graduate
commencement storms due to high speed solar wind from solar coronal
holes. We find that the changes in the "floor" depend on the global
magnetic moment of the Sun, and on the other side, from the height of
the "floor" we can judge about the amplitude of the sunspot cycle.

---------------------------------------------------------
Title: Global complexes of activity
Authors: Obridko, V. N.; Shelting, B. D.
2013ARep...57..786O Altcode:
A new concept of "Global Complexes of Activity" on the Sun is presented,
which brings together objects associated with both global and local
fields in a single framework. Activity complexes have traditionally
been identified purely from observations of active regions. We show
here that a global complex also includes coronal holes and active
regions. Our analysis is based on a large dataset on magnetic fields on
various scales, SOHO/MDI observations of active regions and magnetic
fields, and UV observations of coronal holes. It is shown that the
evolution of coronal holes and active regions are parts of a single
process. The relationships between the fields on different scales
during the generation of the cycle is discussed.

---------------------------------------------------------
Title: Dependence of the solar wind speed on the coronal magnetic
field in cycle 23
Authors: Lotova, N. A.; Obridko, V. N.
2013AstL...39..474L Altcode:
The dependence of the position of the solar wind sonic point on the
magnetic field in the solar corona during cycle 23 is studied. This
dependence is shown to be rather strong in the rising phase and at
the cycle maximum. As the coronal magnetic field grows, the distance
to the sonic point decreases. Since the distance to the sonic point
has been shown previously to anticorrelate with the solar wind speed,
the result obtained suggests a strong positive correlation between the
later and the coronal magnetic field. The situation changed dramatically
two years after the calendar date of the cycle maximum. Beginning in
2004 the solar wind speed ceased to depend on the magnetic field up
until the cycle minimum in December 2008. In 2009 a strong dependence
of the wind speed on the coronal magnetic field was restored. It is
hypothesized that this effect is associated with two different coronal
heating mechanisms whose relative efficiency, in turn, depends on the
contribution from magnetic fields of different scales.

---------------------------------------------------------
Title: Cyclic and secular variations of the inner structure of
sunspot groups
Authors: Obridko, V. N.; Badalyan, O. G.; Bludova, N. G.
2013simi.confE..37O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Co-evolution of the Sun and of life on Earth
Authors: Obridko, V.; Ragulskaya, M.; Rudenchik, E.; Hramova, E.
2013simi.confE..42O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar activity and geomagnetic disturbances
Authors: Obridko, V. N.; Kanonidi, Kh. D.; Mitrofanova, T. A.;
Shelting, B. D.
2013Ge&Ae..53..147O Altcode:
An analysis of IZNIRAN magnetic observatory data indicated that
geomagnetic storms with sudden and gradual commencements form two
independent populations with respect to the disturbance occurrence
time and character because the solar sources of these disturbances are
different. Storms with sudden and gradual commencements are caused by
coronal mass ejections and high-speed solar wind streams from coronal
holes, respectively.

---------------------------------------------------------
Title: Cosmic Ray Modulation At The Solar Activity Minimum And
Ascending Phase In The 24Th Cycle
Authors: Gushchina, R.; Belov, A.; Eroshenko, E.; Obridko, V.;
Shelting, B.
2013ICRC...33.3680G Altcode:
. Recent years have given us the opportunity to explore the long-term
behavior of the cosmic ray (CR) intensity in the unusually deep solar
activity (SA) minimum between the 23rd and the 24th cycles and during
the ascending phase of the SA in the 24th cycle, the lowest cycle
over the history of regular observations of cosmic rays. During the
unusually prolonged minimum SA in CR observed maximum CR intensity
(in 2009) exceeds the previous maximums value of CR in 19-23 cycles
for small energy particles (observed by satellites and stratosphere)
and medium energy (observed by neutron monitors). After 2009, the CR
modulation in the phase of growth of the SA for three years (20 10-2012)
are much weaker than the modulation in the corresponding periods of
the previous cycles SA. Some possible reasons for this anomalies in
CR variations are discussed.

---------------------------------------------------------
Title: Puzzles of the Interplanetary Magnetic Field in the Inner
Heliosphere
Authors: Khabarova, Olga; Obridko, Vladimir
2012ApJ...761...82K Altcode: 2012arXiv1204.6672K
Deviations of the interplanetary magnetic field (IMF) from Parker's
model are frequently observed in the heliosphere at different
distances r from the Sun. Usually, it is supposed that the IMF
behavior corresponds to Parker's model overall, but there is some
turbulent component that impacts and disrupts the full picture of
the IMF spatial and temporal distribution. However, the analysis of
multi-spacecraft in-ecliptic IMF measurements from 0.29 AU to 5 AU
shows that the IMF radial evolution is rather far from expected. The
radial IMF component decreases with the adiabatic power index
(|Br | vprop r -5/3), the tangential component
|Br| vprop r -1, and the IMF strength B vprop
r -1.4. This means that the IMF is not completely frozen
in the solar wind. It is possible that turbulent processes in the
inner heliosphere significantly influence the IMF expansion. This is
confirmed by the analysis of the Br distribution's radial
evolution. Br has a well-known bimodal histogram only at
0.7-2.0 AU. The bimodality effect gradually disappears from 1 AU to
4 AU, and Br becomes quasi-normally distributed at 3-4 AU
(which is a sign of rapid vanishing of the stable sector structure
with heliocentric distance). We consider a quasi-continuous magnetic
reconnection, occurring both at the heliospheric current sheet and
at local current sheets inside the IMF sectors, to be a key process
responsible for the solar wind turbulization with heliocentric distance
as well as for the breakdown of the "frozen-in IMF" law.

---------------------------------------------------------
Title: Coronal Mass Ejections and the Index of Effective Solar
Multipole
Authors: Obridko, V. N.; Ivanov, E. V.; Özgüç, A.; Kilcik, A.;
Yurchyshyn, V. B.
2012SoPh..281..779O Altcode: 2012SoPh..tmp..199O
The paper considers the relationship between the cyclic variations
in the velocity of coronal mass ejections (CME) and the large-scale
magnetic field structure (LSMF) in cycles 21 - 23. To characterize
a typical size of the LSMF structure, we have used the index of
the effective solar multipole (ESMI). The cyclic behavior of the CME
occurrence rate and velocity proved to be similar to that of ESMI. The
hysteresis observed in variations of the CME maximum velocity is
interpreted as a manifestation of different contributions from the
two field structures (local and global magnetic fields) in different
phases of the 11-year activity cycle. It is suggested that cyclic
variations in the maximum velocity of coronal mass ejections are due
to different conditions for the formation of the complexes of active
regions connected by coronal arch systems, which are the main source
of high-velocity CMEs.

---------------------------------------------------------
Title: Puzzles of the Interplanetary Magnetic Field in the Inner
Heliosphere
Authors: Khabarova, O.; Obridko, V.
2012AGUFMSH13A2223K Altcode:
Deviations of the interplanetary magnetic field (IMF) from Parker's
model are frequently observed in the heliosphere at different
distances r from the Sun. Usually, it is supposed that the IMF behavior
corresponds to Parker's model as a whole, but there is some turbulent
component that impacts the full picture of the IMF spatial and temporal
distribution and damages it. However, the analysis of multi-spacecraft
in-ecliptic IMF measurements from 0.29 AU to 5 AU shows that the IMF
radial evolution is rather far from expected. The radial IMF component
decreases with the adiabatic power index (|Br|~r^-5/3), the tangential
component |Bt|~r^-1.1 and, the IMF strength B~r^-1.4. This means that
the IMF is not completely frozen in the solar wind. Possibly, turbulent
processes in the inner heliosphere significantly influence the IMF
expansion. This is confirmed by the analysis of the Br distribution's
radial evolution. Br has a well-known bimodal histogram's view only at
0.7-2.0 AU. The bimodality effect gradually disappears from 1 to 4 AU,
and Br becomes quasi-normally distributed at 3-4 AU (which is a sign
of rapid vanishing of the stable sector structure with heliocentric
distance). We consider a quasi-continuous magnetic reconnection,
occurring both at the heliospheric current sheet and at local current
sheets inside the IMF sectors, as a key process responsible for the
solar wind turbulization with heliocentric distance as well as for
the break of the "frozen-in IMF" law.

---------------------------------------------------------
Title: Potential effects of solar and geomagnetic variability on
terrestrial biological systems Advances
Authors: Babayev, E. S.; Crosby, N. B.; Obridko, V. N.; Rycroft, M. J.
2012asst.book..329B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Global magnetic fields: variation of solar minima
Authors: Tlatov, Andrey G.; Obridko, Vladimir N.
2012IAUS..286..113T Altcode:
The topology of the large-scale magnetic field of the Sun and its
role in the development of magnetic activity were investigated using
H α charts of the Sun in the period 1887-2011. We have
considered the indices characterizing the minimum activity epoch,
according to the data of large-scale magnetic fields. Such indices
include: dipole-octopole index, area and average latitude of the field
with dominant polarity in each hemisphere and others. We studied the
correlation between these indices and the amplitude of the following
sunspot cycle, and the relation between the duration of the cycle
of large-scale magnetic fields and the duration of the sunspot
cycle. The comparative analysis of the solar corona during the
minimum epochs in activity cycles 12 to 24 shows that the large-scale
magnetic field has been slow and steadily changing during the past 130
years. The reasons for the variations in the solar coronal structure
and its relation with long-term variations in the geomagnetic indices,
solar wind and Gleissberg cycle are discussed. We also discuss the
origin of the large-scale magnetic field. Perhaps the large-scale field
leads to the generation of small-scale bipolar ephemeral regions, which
in turn support the large-scale field. The existence of two dynamos:
a dynamo of sunspots and a surface dynamo can explain phenomena such
as long periods of sunspot minima, permanent dynamo in stars and the
geomagnetic field.

---------------------------------------------------------
Title: Extrema of long-term modulation of the cosmic ray intensity
in the last five solar cycles
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2012Ge&Ae..52..438G Altcode:
Modulation of galactic cosmic rays in cycles 19-23 of solar activity has
been determined based on observations of their long-term variations on
the ground and in the near-Earth space. The extreme values of long-term
variations in cosmic rays, obtained from the data of continuous cosmic
radiation monitoring on the ground and in the near-Earth space in the
last five solar cycles, have been analyzed. The results are compared
with the extrema in the characteristics of solar magnetic fields and
the sunspot numbers in these cycles. The similarities and differences
in cosmic ray modulation between different cycles are discussed.

---------------------------------------------------------
Title: Sun evolution as a astrobiology factor of life evolution
Authors: Ragulskaya, Maria; Obridko, Vladimir
2012cosp...39.1555R Altcode: 2012cosp.meet.1555R
The report emphasizes the need to consider the evolution dynamics of
Sun modeling of formation and development of life for the astrobiology
problems. The life processes occurring within ancient environments,
not only depended on stress factors (e.g. temperature, pressure, pH
and chemicals), but especially on the type of emission spectrum of
the early sun and extreme intensity of cosmic rays. 4 billion years
ago the early Sun was significantly different from the current state
of the main star of our planetary system. The intensity of the Sun in
X-ray and ultraviolet spectral regions was much higher in the modern
age than in the era of the formation of life, as shown by IZMIRAN
investigations, 2011 (no the total luminosity was about 70% from the
current level). Solar activity was also more intensive and chaotic. The
intensity of cosmic rays exceeds the current level by several orders
of magnitude. It is known that cosmic rays are a powerful factor
of evolution, but their excess leads to the destruction biological
systems. Perhaps the time of appearance of life was determined
at the moment of transition of solar activity at a more orderly
functioning. Therefore, the evolutionary dynamics of the Sun must be
taken into account to construct models of the earth's life in extreme
environments, as well as the construction of displacement models of
life within the solar system.

---------------------------------------------------------
Title: Experimental observations of the interplanetary magnetic
field distribution in the inner heliosphere: controversial points
Authors: Khabarova, O. V.; Obridko, V. N.
2012EGUGA..14.9383K Altcode:
Interplanetary magnetic field (IMF) deviations from a Parker spiral
are very often observed in the heliosphere at different distances from
the Sun. Commonly, it is supposed that the IMF in the inner heliosphere
corresponds to the Parker theory as a whole, but there is some turbulent
component that impacts a full picture of the IMF spatial and temporal
distribution and damages it. Meanwhile, the analysis of multipoint
in-ecliptic IMF measurements from 0.23 AU to 5 AU shows that the radial
IMF component in the inner heliosphere corresponds neither r-2 law nor
the helicity assumption even under rough average. The next problematic
point is an explanation of observational results on the in-ecliptic
IMF distribution shape at different AU. It is shown that a bimodal
(two-humped) view of Br, RTN (or Bx, By, GSE) distribution, well-known
at 1 AU, is most brightly expressed at low heliolatitudes at 0.7-2
AU, but it disappears with an increasing heliocentric distance. The
in-ecliptic IMF distribution shape becomes perfectly Gaussian-like
at 3-4 AU. Such behaviour of the in-ecliptic IMF can not be explained
by any theory of the IMF extension in space. Therefore, experimental
results, accumulated for the space era, demonstrates the barest
necessity of the 3-D interplanetary magnetic field picture revisiting,
looking for new theories of plasma and IMF expansion from the Sun,
as well as further development of new models of the inner heliosphere.

---------------------------------------------------------
Title: Dynamics of the photospheric magnetic field in the vicinity
of the solar equator
Authors: Obridko, V. N.; Chertoprud, V. E.
2012ARep...56..146O Altcode: 2012AZh....89..173O
SOHO-MDI daily magnetic field synoptic data (a 14-year series of daily
maps of the solar magnetic field intensity B available at the site
http://soi.stanford.edu/magnetic/index5.html) have been used to analyze
the dynamics of the photospheric magnetic field in the vicinity of the
solar equator. The standard deviation s B of the field B
calculated over areas of tens of square degrees on the solar disk was
taken as a basic index. An 11-year variation similar to that observed
at higher latitudes is observed in the vicinity of the equator, and
is similar for weak and strong fields; i.e., the solar cycle exists in
the sunspot-free zone. New qualitative data support the idea that the
weak background magnetic field increases toward the solar limb. This
angular dependence suggests the existence of a transverse component
of the background field. The magnetic fields in the vicinity of the
equator were significantly different in the initial phases of Cycles 23
and 24. Annual variations of s B were observed near the
center of the solar disk. These variations are due to two factors:
the annual variation of the distance from the equator to the disk
center and the increase of s B with with distance from
the equator. Reliable detection of these variations is an evidence of
high accuracy of the s B estimates.

---------------------------------------------------------
Title: The Unusual Sunspot Minimum: Challenge to the Solar Dynamo
Theory
Authors: Obridko, V. N.; Nagovitsyn, Yu. A.; Georgieva, Katya
2012ASSP...30....1O Altcode: 2012snc..book....1O
The last cycle 23 was low, long, complex, and very unusual. The
"peculiarity" of the minimum was that the field was weak, but also that
the morphology of the heliosphere was very complex. A large number
of features of intermediate scale—neither global nor local—were
observed. There are reasons to believe that the amplitude and the period
of a cycle are determined by the large-scale meridional circulation
which, in turn, may be modulated by planetary tidal forces. There
are evidences that at present the deep meridional circulation is
very slow, from which a low and late maximum of cycle 24 can be
predicted. Calculations of the planetary tidal forces indicate that
cycle 25 will be still lower, and therefore cycle 24 is the beginning
of a secular solar activity minimum. Various prediction methods are
summarized, all indicating that we are entering a period of moderately
low activity, and the possibility of a Maunder-type minimum is very
small. Arguments are also presented in favor of a near-surface dynamo.

---------------------------------------------------------
Title: Scenario of Evolution of the Epoch of Minimum at the Final
Stage of Cycle 23
Authors: Lotova, N. A.; Obridko, V. N.
2012ASSP...30..179L Altcode: 2012snc..book..179L
The paper is devoted to the study of 11-year cycles of solar activity
with an emphasis on the peculiar features observed at the final stage
of Cycle 23. The study is based on information on the solar wind stream
structure and its relation to the solar wind sources in the corona.

---------------------------------------------------------
Title: The Sun: New Challenges
Authors: Obridko, Vladimir N.; Georgieva, Katya; Nagovitsyn, Yury A.
2012ASSP...30.....O Altcode: 2012snc..book.....O
No abstract at ADS

---------------------------------------------------------
Title: Magnetohydrostatic model for a coronal hole
Authors: Obridko, V. N.; Solov'ev, A. A.
2011ARep...55.1144O Altcode: 2011AZh....88.1238O
A model treating a solar coronal hole as an axially symmetrical
magnetic formation that is in equilibrium with the surrounding medium is
proposed. The model is applicable in the lower corona (to heights of the
order of several hundreds of Mm), where the influence of the solar-wind
outflow on the state of the system can still be neglected. The magnetic
field of the coronal hole is comprised of a relatively weak open flux
that varies with height, which extends into interplanetary space, and
a closed field, whose flux closes at the chromosphere near the coronal
hole. Simple analytical formulas are obtained, which demonstrate for
a given equilibrium configuration of the plasma and field the main
effect of interest—the lowering of the temperature and density of
the gas in the coronal hole compared to their values in the corona at
the same geometric height. In particular, it is shown that, at heights
of several tens of Mm, the temperature and density of the plasma in
the coronal hole are roughly half the corresponding values at the
same height in the corona, if the cross-sectional radius of the hole
exceeds the scale height in the corona by roughly a factor of 1.5: R
 h ≈ 1.5 H( T 0). In the special case when R
 h ≈ H( T 0), the plasma temperature in the
hole is equal to the coronal temperature, and the darkening of the
coronal hole is due only to an appreciable reduction of the plasma
density in the hole, compared to the coronal density. An analogy of
the properties of coronal holes and sunspots is discussed, based on the
similarity of the magnetic structures of these formations. In spite of
the fundamental difference in the mechanisms for energy transport in
coronal holes and sunspots, the equilibrium distributions of the plasma
parameters in these formations are determined only by the magnetic and
gravitational forces, giving rise to a number of common properties,
due to their similar magnetic structures.

---------------------------------------------------------
Title: TAHOMAG - vector-magnetograph for INTERHELIOPROBE
Authors: Kozhevatov, I. E.; Obridko, V. N.; Rudenchik, E. A.
2011sdmi.confE..75K Altcode:
Presented is the design of TAHOMAG - a vector-magnetograph for the
INTERHELIOPROBE space mission. Since the instrument is supposed
to conduct measurements under the conditions of strongly changing
spacecraft velocity with respect to the Sun, we have chosen the scheme
of a magnetograph with a spectrograph. A part of the spectrum of length
6Å is fixed in the vicinity of the FeI 6302 Å line. The contours of
the Stokes parameters are recorded with a high spectral resolution. The
polarization analyzer does not have mobile parts. The spatial resolution
in the vicinity of the perihelion (0.3 a.u.) is expected to be 50-75 km.

---------------------------------------------------------
Title: North-South asymmetry of the sunspot indices and its
quasi-biennial oscillations
Authors: Badalyan, O. G.; Obridko, V. N.
2011NewA...16..357B Altcode:
The space-time distribution of asymmetry in the area and total
number of sunspot groups was considered over the time interval
1874-2009. The time behavior of the asymmetry in these indices of
sunspot activity was shown to be similar on both small and large
time scales. Spectral variation analysis (SVAN) was applied to study
the spectral characteristics. Quasi-biennial oscillations (QBO)
were revealed in the asymmetry of both indices under discussion. The
SVAN diagrams for the asymmetry of the areas and numbers of sunspots
in the range of QBO periods display pronounced similarity. In the
activity indices per se, these effects are much weaker: the mutual
correlation of the indices is lower, the QBO are less pronounced, and
the similarity of the SVAN diagrams in the QBO range is absent. The
effect of negative correlation between the QBO power and absolute value
of the asymmetry over a long time interval was revealed: the increase
in asymmetry is accompanied by a decrease in QBO amplitude regardless
of which hemisphere is more active at the moment. This underlines the
global nature of QBO and the relation of asymmetry to the quadrupole
component of the solar large-scale magnetic field. The asymmetry is
an independent fundamental characteristic of solar activity, which
does not reduce to the classical characteristics of the 11-year cycle.

---------------------------------------------------------
Title: `Active Longitudes' in the Heliomagnetic Reference Frame
Authors: Obridko, V. N.; Chertoprud, V. E.; Ivanov, E. V.
2011SoPh..272...59O Altcode: 2011SoPh..tmp..322O; 2011SoPh..tmp..271O; 2011SoPh..tmp..202O;
2011SoPh..tmp..297O
A new coordinate system - heliomagnetic reference frame - has been
proposed in which the great circle passes through the solar pole and
the north pole of the magnetic dipole is considered as the central
meridian. It is shown that, in the new coordinate system, the active
longitudes are defined much more clearly, are more stable in time,
and are interlaced every 11 years.

---------------------------------------------------------
Title: Unexpected Solar Activity Cycle 24 Prediction by Various
Methods
Authors: Breus, T. K.; Ozheredov, V. A.; Obridko, V. N.
2011simi.confQ...1B Altcode:
A considerable difference in maximum amplitude of the solar cycle
(SC) 24 predicted by various methods exists according to conclusion
of the Third Official Prediction Panel NOAA, NASA and International
Environment Service (ISSE). Aim of our study is to update SC 24 forecast
by comparative analysis of this problem using linear autoregressive
approaches, nonlinear Neural - based method and method of precursor. As
a predictor for construction of SC 24, we used an idea on dynamics
of the solar magnetic fields forming solar spots, being basic for
estimations of Wolf numbers Wn. For forecasting of variations of
predictor – the solar polar field - in SC 24 the singular spectral
analysis was used. Results: Our nonlinear Neural-based prediction gave
value 70 for SC 24 amplitude in contrast with value 145 from official
two predictions based on Neural network methods. The proposed
forecasting by precursor method based on solar polar field variations
allows expanding a horizon of Wn prediction on one cycle. The SC 24
maximum is predicted by this method had to happen in April, 2012, and
its average amplitude can be as low as 50 or even 20. The prolonged
minimum of the Solar Cycle 23 and abnormal predicted values of Wn for
the maximum of Solar Cycle 24 remind the scenario of transition of
solar activity to the historical Dalton minimum.

---------------------------------------------------------
Title: Coronal Holes and High Speed Streams
Authors: Obridko, V. N.
2011simi.conf....6O Altcode:
We have analyzed the data on coronal holes observed in the Sun
throughout the activity Cycle 23. It is shown that CH is not merely an
undisturbed zone between the active regions. The reduced brightness
is the result of a specific structure with the magnetic field being
quasi-radial at as low altitude as 1.1R or a bit higher. The plasma
outflow decreases the measure of emission from CH. With an adequate
choice of the photometric boundaries, the CH area and brightness
indices display a fairly high correlation (0.6-0.8) with the solar
wind velocity throughout the cycle. The mean brightness of the darkest
part of CH is of the order of 18-20% of the solar brightness, while
the brightness of the other parts of the CH is 30-40%. It is shown
that the parameters of the solar–wind magnetic field are determined
at the level of 1.1–1.4 solar radii in the coronal hole, where the
field lines are radial at low heights. Traditional comparison of the
field parameters at the Earth orbit and at the Earth helioprojection
point on the Sun is not quite correct. It is justified as far as
the signs of the field and sector structure are concerned. However,
the field absolute value is formed in a more extensive area. Taking
this into account, we can correlate the field values in the Sun with
the values of the IMF and explain the absence of weak fields in the
vicinity of the IMF neutral line (two-peak distribution).

---------------------------------------------------------
Title: Longitude variations of solar magnetic fields of different
intensity in cycle 23 as inferred from the SOHO/MDI data
Authors: Obridko, V. N.; Chertoprud, V. E.
2011AstL...37..358O Altcode: 2011PAZh...37..392O
SOHO/MDI magnetograms have been used to analyze the longitude
distribution of the squared solar magnetic field &lt; B 2&gt;
in the activity cycle no. 23. The energy of the magnetic field (&lt;
B 2&gt;) is shown to change with longitude. However, these
variations hardly fit the concept of active longitudes. In the epochs
of high solar activity, one can readily see a relationship between
longitude variations of the medium-strong ((| B| &gt; 50 G or | B| &gt;
100 G) and relatively weak (| B| ≤ 50 G or | B| ≤ 100 G) fields at
all latitudes. In other periods, this relationship is revealed mainly
at the latitudes not higher than 30°. The background fields (| B|
≤ 25 G) also display longitude variations, which are, however, not
related to those of the strong fields. This makes us think that the
fields of solar activity are rather inclusions to the general field
than the source of the latter.

---------------------------------------------------------
Title: Relationship between the Parameters of Coronal Holes and
High-Speed Solar Wind Streams over an Activity Cycle
Authors: Obridko, V. N.; Shelting, B. D.
2011SoPh..270..297O Altcode: 2011SoPh..tmp...59O; 2011SoPh..tmp...82O
The comparison of the brightness and area of coronal holes (CH) to the
solar wind speed, which was started by Obridko et al. (Solar Phys.260,
191, 2009a) has been continued. While the previous work was dealing
with a relatively short time interval 2000 - 2006, here we have analyzed
the data on coronal holes observed in the Sun throughout activity Cycle
23. A catalog of equatorial coronal holes has been compiled, and their
brightness and area variations during the cycle have been analyzed. It
is shown that CH is not merely an undisturbed zone between the active
regions. The corona heating mechanism in CH seems to be essentially
the same as in the regions of higher activity. The reduced brightness
is the result of a specific structure with the magnetic field being
quasi-radial at as low an altitude as 1.1R⊙ or a bit
higher. The plasma outflow decreases the measure of emission from
CH. With an adequate choice of the photometric boundaries, the CH area
and brightness indices display a fairly high correlation (0.6 - 0.8)
with the solar wind velocity throughout the cycle, except for two years,
which deviate dramatically - 2001 and 2007, i.e., the maximum and the
minimum of the cycle. The mean brightness of the darkest part of CH,
where the field lines are nearly radial at low altitudes, is of the
order of 18 - 20% of the solar brightness, while the brightness of the
other parts of the CH is 30 - 40%. The solar wind streams originate at
the base of the coronal hole, which acts as an ejecting nozzle. The
solar wind parameters in CH are determined at the level where the
field lines are radial.

---------------------------------------------------------
Title: Solar Activity Cycle in Solar-wind Sources and Flows
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.
2011SoPh..269..129L Altcode: 2010SoPh..tmp..243L
Experiments based on multi-source radio occultation measurements of
the circumsolar plasma at R∼4.0−70RS were carried out
during 1997 - 2008 to locate the inner boundary of the solar-wind
transonic transition region, Rin. The data obtained were
used to correlate the solar-wind stream structure and magnetic fields
on the source surface (R=2.5RS) in the solar corona. The
method of the investigation is based on the analysis of the dependence
Rin=F(|BR|) in the correlation diagrams, where
Rin is the inner boundary of the solar-wind transition
region and |BR| is the intensity of the magnetic field
at the source surface. On such diagrams, the solar wind is resolved
into discrete branches, streams of different types. The analysis of
the stream types using a continuous series of data from 1997 to 2008
allowed us to propose a physical criterion for delimiting the epochs
in the current activity cycle.

---------------------------------------------------------
Title: Open magnetic fields on the Sun and solar wind parameters at
the Earth's orbit
Authors: Obridko, V. N.; Shelting, B. D.; Livshits, I. M.
2011ARep...55..284O Altcode: 2011AZh....88..313O
It is shown that the parameters of the solar-wind magnetic field are
determined by regions in coronal holes at distances of 1.1-1.4 solar
radii, where the field lines are radial at low heights. Expanding
further in a narrow nozzle or funnel, the field lines become
radial throughout the unipolar region at 2.5 solar radii. Hence,
the traditional approach of comparing the characteristics of the
interplanetary field at the Earth's orbit and at the corresponding
helio-projection point on the Sun is not quite correct. It gives good
results for the signs and sector structure of the field; however,
the magnitude of the field is formed in a more extensive area. Taking
this into account, we can correlate the field values on the Sun with
the interplanetary magnetic field (IMF), and thus explain the absence
of weak fields in the vicinity of the IMF neutral line (the two-peaked
nature of the distribution).

---------------------------------------------------------
Title: On the nature of the in-ecliptic interplanetary magnetic
field's two-humped distribution at 1AU
Authors: Khabarova, Olga; Obridko, Vladimir
2011arXiv1102.1176K Altcode:
It was found out that the distribution's shape of the in-ecliptic (as
well as radial) component of the interplanetary magnetic field (IMF)
significantly changes with the heliocentric distance, which poorly
corresponds to classical models of the solar wind and the interplanetary
magnetic field (IMF) expansion. For example, distributions of the
radial photospheric and the source surface's magnetic field in the
ecliptic plane are Gaussian-like, the distribution of the radial
IMF component at the Earth orbit demonstrates two-humped shape, and
it becomes again Gaussian-like at 3-4 AU. These differences lead to
lack of correspondence between simulations of the IMF behaviour at
1 AU and observations. Our results indicate that picture of the IMF
expansion into space is more complicated than usually considered, and
the sector structure is not the only source of the two-humped shape of
the in-ecliptic or radial IMF component. We have analysed data from
different spacecraft at the distances from 0.29 AU to 4 AU and found
that the shape of the radial IMF component distribution strongly depends
on a heliocentric distance and a heliolatitude. The "two-humped IMF"
effect is most brightly expressed at low heliolatitudes at 0.7-2 AU,
but it fully disappears at 3-4 AU. There is also dependence of the
IMF distributions' view on a solar cycle due to active processes, such
as solar flares and CMEs. We suppose that the in-ecliptic solar wind
field at 1 AU is influenced by solar active regions in a high degree,
and actually the distribution is the three-humped: two humps correspond
to the IMF from the middle and high heliolatitudes and the third one
is the theoretically expected distribution from the solar field nearby
the heliomagnetic equator. Vanishing of the IMF zero-component with
the distance from the Sun partially could be a result of a magnetic
reconnection at the current sheets in the solar wind.

---------------------------------------------------------
Title: Diagnostics of solar wind streams and their sources in the
solar corona
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.
2010Ge&Ae..50..711L Altcode:
The studies are based on the experimental mass sounding of the
interplanetary plasma near the Sun at radial distances of R = 4-70 R
S, performed at Pushchino RAO, Russian Academy of Sciences,
and on the calculated magnetic fields in the solar corona based on the
magnetic field strength and structure measured on the Sun's surface at
J. Wilcox Solar Observatory, United States. The experimental data make
it possible to localize the position of the boundary closest to the Sun
of the transition transonic region of the solar wind in the near-solar
space ( R ≈ 10-20 R S) and to perform an interrelated
study of the solar wind structure and its sources, namely, the magnetic
field components in the solar corona based on these data. An analysis
of the evolution of the flow types in 2000-2007 makes it possible to
formulate the physically justified criterion responsible for the time
boundaries of different epochs in the solar activity cycle.

---------------------------------------------------------
Title: Correction of Observations When Calculating Heliospheric
Magnetic Fields from Solar Magnetograph Data
Authors: Obridko, V. N.; Asgarov, A. B.; Shelting, B. D.; Babayev,
E. S.
2010SunGe...5...34O Altcode:
The nature of the discovered difference between the histograms of
distribution of the daily mean magnetic fields in the heliosphere near
the Earth and on the source surface in the Sun is discussed. The
magnetic field measured near the Earth is a bit smaller than
the calculated one and has a two-peak distribution. We propose
a new correction method, which takes into account the saturation
of magnetographs and the contribution of high-latitude fields. The
calculations carried out by this method display better agreement with
observations; however a detailed distribution of fields inside the
sector can not be described by a simple classical model.

---------------------------------------------------------
Title: Long-term modulation of galactic cosmic rays at solar activity
minimums
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2010Ge&Ae..50..436G Altcode:
Based on observations of long-term variations in galactic cosmic
rays (CRs) on Earth and in the near-Earth space, we have determined,
using our own semiempirical model, modulation of galactic CRs during
solar cycles 19-23. The modulation model relates CR variations to the
characteristics of the solar magnetic field obtained for the surface
of the solar wind source at distances of 2.50 and 3.25 solar radii. The
main focus is CR behavior at the minimums of cycles 19-23 and specific
features of CR modulation at a prolonged (as compared to previous
cycles) minimum of cycle 23, which is still ongoing. CR modulation at
minimums related to a change in the solar field dipole component during
this period of the cycle has been considered. It is indicated that the
long-term variations in CRs are better described if the last two years
(2007 and 2008) of cycle 23 with anomalously low solar activity (SA)
are included in the model. The role and value of the contribution of
the cyclic variations in each index used in the proposed CR modulation
model to the observed CR modulation have been estimated.

---------------------------------------------------------
Title: Large-scale patterns and ‘active longitudes’
Authors: Obridko, Vladimir N.
2010IAUS..264..241O Altcode:
The following aspects of the physics of large-scale solar magnetic
fields are discussed: structure of large-scale fields (LSF)
and connection with local fields; dynamo and origin of LSF; LSF
cycle variation; meridional circulation and LSF; rotation of LSF;
fine structure of the field in quiet regions and the concept of the
pebble-shaped field; active longitudes, their manifestation in various
solar indices, and dependence on the power of solar activity.

---------------------------------------------------------
Title: Magnetic reconnection as a possible cause of in-ecliptic IMF
zero vanish on the way from the Sun to the Earth
Authors: Khabarova, Olga; Obridko, Vladimir
2010cosp...38.1932K Altcode: 2010cosp.meet.1932K
If we look at the distributions of Bx and By -horizontal components
of interplanetary magnetic field (IMF) at the Earth orbit, we can see
striking hole in the area near zero. There are two peaks of By and Bx
distributions: one negative and one positive, while the Bz component
is distributed around zero. For many years this fact has been simply
explained by geometrical considerations. It has been supposed that
sector structure of IMF leads to observation of predominant negative
or positive horizontal IMF component sign, first of all, because
heliospheric current sheet (where zero magnetic line always exists)
is enough thin and it passes the Earth very fast in comparison with
the positive or negative sector stay time. The next explanation was
the high inclination of the heliospheric current sheet, which is often
concidered to be perpendicular to the ecliptic plane. These explanations
seemed so obvious that the problem even had not been discussed in
the literature so long as V.Obridko in 2006 pointed out at the fact
of significant mismatching of horizontal IMF components distribution
near the Earth and distribution of magnetic field at the Sun (for
the projection of the Earth to the solar wind source surface). Solar
magnetometers allow measure radial component of magnetic field at the
Sun with the accuracy and time resolution enough for comparison with
near-Earth IMF spacecraft data. The radial solar magnetic field in
the interplanetary space should decrease as r-2 for a quiet flowing
out stream. Modern successful calculations of in-ecliptic IMF at the
Earth orbit are mainly based on this law, but calculated horizontal
field values are permanently lower than measured ones. Moreover,
distribution of radial solar magnetic field is fundamentally different
from spacecraft measured in-ecliptic magnetic field distribution:
there is no double-humped distribution of field at the Sun; it is usual
Gauss-like one. It was shown these variances can not be explained by
"technical" causes, and it is necessary to seek for physical nature
of these differences. There are evidences that near-Earth "zero" is
lost even at the heliospheric current sheet. Shortfall of IMF zero
values could be explained by unceasing magnetic reconnection at the
heliospheric current sheet (sector boundary) as well as at current
sheets often associating with the streamer belt. As a result the main
zero-line gets thinner and thinner on the way from Sun to the Earth,
and the heliosheric current sheet becomes wider, looks like a sandwich,
full of reconnection's products. Simulation results and experimental
proofs of reconnection at the heliospheric current sheets and at
small-scale current sheets in space plasma are given.

---------------------------------------------------------
Title: Influence of space weather on human organism at different
geo-latitudes: telecommunication helio-medical monitoring "Geliomed"
2003-2010
Authors: Ragulskaya, Maria; Obridko, Vladimir; Samsonov, Sergey;
Vitaliy, Vishnevskey; Grigoryev, Pavel; Valeriy, Pipin; Khabarova, Olga
2010cosp...38.3401R Altcode: 2010cosp.meet.3401R
We discuss the results of the long-term telecommunicative biogeophysical
monitoring "Geliomed" (2003-2010). The purpose is to explore the
effects of spatial and temporal variations in space weather and
climatic factors on the human health state. The monitoring is carried
out simultaneously at the different geographical areas that covers the
different latitudes. The project developed in the joint collaboration
the Ukrainian National Academy of Science and the Russian Academy of
Science. The experiment carried out simultaneously in Moscow, Yakutsk,
Kiev and Simferopol. The principal components of the experiment can
be summarized as follows: 1. Equipments and data gathering methods
are the same for all the scientific cen-ters which are involved in
experiment. Research centers working with the same equipment and
using the same protocols with on-line registration of current data
on same portal server (http//geliomed.immsp.kiev.ua) 2. The groups
of patients involved in the program are kept the same for the whole
observational period of time. 3. The daily registered parameters
in-clude: psycho-emotional tests and 1-st lead ECG (contain 25
000 measurements for the whole period), arterial pressure (100 000
measurements), variability cardiac contraction (25000 mea-surements),
electric conduction of bioactive points on skin (more than 500 000
measurements for the whole period ). 4. The every patient in the
monitoring group is examined at the 4 functional states. Registration is
done at rest, after standard psychology test, Roufiet test, and after
10 min relax. 5. The data of the ECG measurements are analyzed in the
phase space constructed from the signal and its derivative. 6. The
results time series were compared with daily values of space weather
and geomagnetic parameters. Results. In the all monitoring centers all
the patients involved in the monitoring show the same type of changes in
the cardiac activity parameters during an isolated magnetic storm. Such
a change of the ECG parameters occurs nearly simultaneously for all
the centers. The higher latitude, the greater amplitude of the ECG
parameters change. The properties of the detected phenomena can be
summarized as follows: -The dynamics of adaptation programs changes
during the storm. The maximum amplitude of change is observed for
the healthy patients. -The number of none-typical ECG beats increase;
-There are no clear evidences for variations of RR intervals during
geomagnetic storms. -Man are more sensitive to magnetic storms, while
endogenous rhythms predominate for females; Additionally, we find, that
the embedding of ECG time series in 3D phase space can be considered
as a mix of a few states. At the rest, the occurrence of the basic ECG
state compare to additional ones is about 8:2. The occurrence of the
basic state increases after the stress. Thus, the external stress may
change the relative disorder of the system. To understand the origin
of the standard cardio-cycle changes we reconstruct of the dynamical
model of the individual cardiac beat. The reconstruction reveals
that the typical evolution of the cardiac rhythm includes the drift
of attractor in the embedding space and the sudden change between
a few basic patterns of attractor. However one of pattern is always
dominating. These several pattern of ECG beat attractor can be ascribed
to a several states of the system. Qualitatively, the nonlinear ECG
dynamics is defined by the stationary points, which are inside into
Q and T waves. Conclusions: many-year telecommunication heliomedical
monitoring in different lat-itudes showed, that space and geophysical
factor act as a training factor for the adaptation-resistant member
of the population. It serve as a channel for rejection of nonviable
members of the population, synchronize the total populations rhythms,
create conditions for generation of new information in the process of
evolution adaptation of biological systems in general.

---------------------------------------------------------
Title: Possible Effects of Solar and Geomagnetic Activity on Sudden
Cardiac Death in Middle Latitudes
Authors: Dimitrova, S.; Babayev, E. S.; Georgieva, K.; Obridko, V. N.;
Mustafa, F. R.
2009SunGe...4...84D Altcode:
In this paper results revealing potential effects of solar activity (SA)
and geomagnetic activity (GMA) on the dynamics of sudden cardiac death
(SCD) in middle latitudes are described. Medical data were taken from
all of emergency and first medical aid stations of Grand Baku Area
with millions of inhabitants for the time period 2003-2005. In total
788 SCD cases were analyzed. ANalysis Of VAriance (ANOVA) was applied
to study the significance of GMA influence, estimated by different
geomagnetic indices, and the type of geomagnetic storms (caused by
the solar origin magnetic clouds (MC) and by high speed solar wind
streams (HSSWS)) on SCD. Correlation analysis was carried out and
relevant coefficients were calculated. Obtained results revealed
strong negative correlation between monthly averaged GMA and SCD in
Baku for the considered period. ANOVA revealed that SCD number was
largest on the days of low GMA, on the days of highest geomagnetic
field variations and even on +2nd day after them. It was established
that SCDs increased on the days of storms caused by HSSWS and remained
higher till +2nd day after they finished.

---------------------------------------------------------
Title: Contrast of Coronal Holes and Parameters of Associated Solar
Wind Streams
Authors: Obridko, V. N.; Shelting, B. D.; Livshits, I. M.; Asgarov,
A. B.
2009SoPh..260..191O Altcode:
It is shown that the contrast of coronal holes, just as their size,
determines the velocity of the solar wind streams. Fully calibrated EIT
images of the Sun have been used. About 450 measurements in 284 Å have
been analyzed. The time interval under examination covers about 1500
days in the declining phase of cycle 23. All coronal holes recorded
for this interval in the absence of coronal mass ejections (CMEs) have
been studied. The comparison with some other parameters (e.g. density,
temperature, magnetic field) was carried out. The correlations with the
velocity are rather high (0.70 - 0.89), especially during the periods
of moderate activity, and could be used for everyday forecast. The
contrast of coronal holes is rather small.

---------------------------------------------------------
Title: Relationship between the contrast of coronal holes and
parameters of the solar wind streams
Authors: Obridko, V. N.; Shelting, B. D.; Livshits, I. M.; Askerov,
A. B.
2009ARep...53.1050O Altcode: 2009AZh....86.1125O
It is shown that the contrast of coronal holes (CH) determines the speed
of the solar wind streams to the same extent as their area does. We
analyzed more than 400 images obtained in the λ284 Å channel. The time
interval under examination covers about 1500 days in the declining
phase of cycle 23 (from 2002 to 2006). We considered all coronal
holes recorded during that interval in the absence of coronal mass
ejections (CME). Comparison was also made with some other parameters
of the solar wind (e.g., density, temperature, and magnetic field). A
fairly high correlation (0.70-0.89) was obtained with the velocity,
especially during the periods of moderate activity, which makes this
method useful for everyday forecast. The ratio of CH brightness to
the mean brightness of the disk in the λ284 Å channel is about 25%.

---------------------------------------------------------
Title: Fine-scale Stochastic Structure of Solar Magnetic Fields
Authors: Chertoprud, V.; Ioshpa, B.; Obridko, V.
2009ASPC..405..205C Altcode:
Fine-structure (∼10”) stochastic properties of the magnetic field
of the Sun have been analyzed in the frames of a two-dimensional model
of the fractal Brownian process (mean square of the field magnitude
difference at two points spaced by a distance D is proportional to
D2H). The standard deviation s of the magnetic field and
the exponent H corresponding to different levels of mid Bmid have
been determined using digitized solar magnetograms with 2” resolution
\citep[SOHO/MDI,][]{chertoprud_Scherrer_1995}. It is established that
transition from the background magnetic field to the active region (AR)
magnetic fields occurs in the field region 25-50 G. The exponent H has
been determined as a function of the magnetic field magnitude. The
exponent H for the background magnetic field is essentially smaller
than for the AR fields. The relation between the results obtained and
some fundamental properties of the behavior of solar plasma (turbulence,
convection) are discussed.

---------------------------------------------------------
Title: Small-scale background magnetic field on the sun in solar
cycle 23
Authors: Ioshpa, B. A.; Obridko, V. N.; Chertoprud, V. E.
2009AstL...35..424I Altcode: 2009PAZh...35..472S
Based on SOHO/MDI data (an archive of magnetic maps with a resolution
of ∼2″), we have investigated the dynamics of the small-scale
background magnetic field on the Sun in solar cycle 23. The cyclic
variations and surface structure of the background magnetic field
have been analyzed using the mean estimates of &lt; B&gt; and
&lt; B 2&gt; of the observed magnetic field strength B
for various solar surface areas and at various B levels. We have
established that the cyclic variations of &lt;2&gt; at latitudes
below 30° are essentially similar to those of the total radio flux
F 10.7. A significant difference between the background
magnetic fields in the northern and southern solar hemispheres
persisting throughout the solar cycle has been detected. We have found
the effect of background magnetic field growth toward the solar limb and
concluded that the transversal component in the background magnetic
field is significant. The relatively weak small-scale background
magnetic fields are shown to form a special population with its own
special laws of cyclic variation.

---------------------------------------------------------
Title: About the role of the Sun magnetic field characteristics in
the long-term galactic cosmic rays modulation
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2009BRASP..73..334G Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Anomalies in the evolution of global and large-scale solar
magnetic fields as the precursors of several upcoming low solar cycles
Authors: Obridko, V. N.; Shelting, B. D.
2009AstL...35..247O Altcode: 2009PAZh...35..279O
Anomalies in the solar magnetic fields of various scales are
studied. The polar magnetic field strength is shown to have decreased
steadily during the last three solar cycles. This is because the
increase in the dipole magnetic moment observed from 1915 to 1976 has
changed into a decrease in the last three cycles. At the same time,
the medium scale magnetic fields (like those of isolated coronal
holes) have been unusually strong in the last cycle. As a result,
the tilt of the heliospheric current sheet is still about 30°. The
large effective contribution from the medium scale fields to the total
energy of the large-scale fields is also confirmed by our calculations
of the effective multipolarity index. The aa-index at the cycle minima
is correlated with the height of the succeeding maxima. The set of data
considered may be indicative of the possible approach of a sequence
of low solar cycles.

---------------------------------------------------------
Title: The role of cyclic solar magnetic field variations in the
long-term cosmic ray modulation
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2009AdSpR..43..673G Altcode:
Updating the semi-empirical model of cosmic rays (CR) modulation
proposed in our previous work has been discussed. In order to provide a
description of long-term variations, in which the CR modulation would
adequately reflect the complex interaction of global and local solar
magnetic fields, we have supplemented the model with the following
characteristics: the solar magnetic field polarity, the integral index,
the partial indices, the tilt of the current sheet, and the index
characterizing the X-ray flares. The role of each index in the CR
modulation has been determined. In the multi-parameter description of
long-term CR variations using the integral index or one of four partial
indices, the best fit for the period 1977-1999 has been obtained for
the integral index and the sector-odd index characterizing the inclined
dipole. The discrepancy between the model and observations increases
from the beginning of 2000. Therefore, the problematic features in the
behavior and modeling of CR during cycle 23 have been discussed. It
is suggested that the cycle-to-cycle decrease of the CR density in
the minimum epochs of the past solar activity (SA) cycles could be
explained by the decrease of the zone-odd index.

---------------------------------------------------------
Title: The reflection in the long-term cosmic rays modulation of
the cyclic variations of integral and partial indices of the solar
magnetic field
Authors: Gushehina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2009ecrs.conf..226G Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Manifestations of cyclic variations in the solar magnetic
field in long-term modulation of cosmic rays
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.
2008Ge&Ae..48..571G Altcode:
The possibilities of improving the semiempirical model of cosmic
ray (CR) modulation, proposed by us previously, are discussed. The
following characteristics have been considered as model parameters in
order to describe long-period CR variations using a unified model and
to more completely reflect solar cycles in CR modulation as a complex
interaction between two systems of fields (large-scale and local):
the value and sign of the polar solar field, the average strength
of the solar magnetic field (the B ss integral index),
partial indices (zone-even ( ZE) and zone-odd ( ZO) and sector-even
( SE) and sector-odd ( SO) indices), the tilt of the heliospheric
current sheet, and the special index ( F x ) taking into
account X ray flares. The role of each index in CR modulation has been
revealed. When we described the long-term CR variations using many
parameters and taking into account the integral index or one of four
partial indices, the best results of modulation modeling during 1976
1999 were obtained for the B ss total energetic index and
SO index. A difference between the model calculations and observations
increases beginning from the middle of 2000; the problem features of the
CR behavior and the specific features of modeling this behavior in cycle
23 of solar activity (SA) are discussed. It is assumed that a decrease
in the CR density at the last SA minimums (from cycle to cycle) can be
related to a decrease in the ZO index and to a recently detected similar
decrease in the vertical component of the solar dipole magnetic moment.

---------------------------------------------------------
Title: Predictions of the Magnitude of the Forthcoming Solar Cycles
using Knowledge on the Solar Dynamo and Singular Spectrum Analysis
Authors: Kuzanyan, K.; Obridko, V. N.; Kotlyarov, O. L.; Loskutov,
A. Y.; Istomin, I. A.
2008ESPM...12.2.69K Altcode:
We present results of a series of studies on revealing regularities
and predictions of the magnitude and duration of the solar cycle by
simultaneous use of the knowledge on the Solar Dynamo mechanism and
the arsenal of time series methods, such as Singular Spectrum Analysis
(SSA). The key properties of the solar dynamo have been obtained
by consideration of the nonlinear Parker dynamo waves in a thin shell,
which enables links between amplitude and phase of the solar magnetic
activity. Further, the sunspot index series have been analysed using
time series methods, and predictions on the magnitude of this activity
has been produced. On the basis of these computations we expect
the two forthcoming solar cycles to be a bit lower than the previous
ones, namely the maximum 12-month averaged Wolf number for the cycle 24
is expected in the second half of 2011 as approximately 106, and for
cycle 25 in 2021 about 99, given the uncertainties. Furthermore,
the theory of nonlinear dynamo waves establishes a link between the
growth rate of the solar activity in the phase of rise of the cycle
with its maximum value, supported by observational regularities. We
are going to refine our predictions of this cycle 24 maximum magnitude
shortly, once the stable cycle growth is indicated.

---------------------------------------------------------
Title: Temporal variations in the position of the heliospheric equator
Authors: Obridko, V. N.; Shelting, B. D.
2008ARep...52..676O Altcode: 2008AZh....85..750O
It is shown that the centroid of the heliospheric equator undergoes
quasi-periodic oscillations. During the minimum of the 11-year cycle,
the centroid shifts southwards (the so-called bashful-ballerina
effect). The direction of the shift reverses during the solar
maximum. The solar quadrupole is responsible for this effect. The
shift is compared with the tilt of the heliospheric current sheet.

---------------------------------------------------------
Title: Diagnostics of solar wind flows
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.
2008AstL...34..500L Altcode: 2008PAZh...34..551L
The formation of the solar wind, the plasma flows from the Sun,
is studied by new methods that have been developed in recent
years. Experiments on circumsolar plasma sounding at radial heliocentric
distances of ∼2.5 60 R ⊙ form their basis. Experimental
data are used to construct the correlation diagrams-the location of
the boundary of the transonic solar wind transition region versus
the magnetic field strength in the region of the flow sources. The
2000 2004 correlation diagrams reveal flows of six types that differ
by the magnetic field structure in their sources. During the decline
of solar activity in 2003 2004, the evolution of the slow solar wind
flows has been found to be determined not by the Wolf numbers, but by
the total strength of the global magnetic field in the solar corona.

---------------------------------------------------------
Title: On Prediction of the Strength of the 11-Year Solar Cycle No. 24
Authors: Obridko, V. N.; Shelting, B. D.
2008SoPh..248..191O Altcode: 2008SoPh..tmp...38O
Various forecast techniques have been analyzed with reference to solar
activity cycle 24. Three prediction indices have been proposed: the
intensity of the polar field, the mean field at the source surface,
and a recurrence index of geomagnetic disturbances. As a rule, the
forecast based on the polar field and extrapolation of local fields
gives a height for cycle 24 that is smaller than that of cycle 23. The
use of the recurrence index and the global field value leads us to the
conclusion that cycle 24 will be medium high: the same as or somewhat
higher than cycle 23.

---------------------------------------------------------
Title: Fractal properties of solar magnetic fields
Authors: Ioshpa, B. A.; Obridko, V. N.; Rudenchik, E. A.
2008AstL...34..210I Altcode: 2008PAZh...34..234I
We study the spatial properties of solar magnetic fields using data
from the Solar Vector Magnetograph of the Marshall Space Flight
Center (MSFC) (FeI 5250.2 Å) and SOHO/MDI longitudinal magnetic
field measurements (Ni 6767.8 Å) (96-min full-disk maps). Our study
is focused on two objects: the fractal properties of sunspots and
the fractal properties of the spatial magnetic field distribution
of active and quiet regions considered as global structures. To
study the spatial structure of sunspots, we use a well-known method
of determining the fractal dimension based on an analysis of the
perimeter—area relation. To analyze the fractal properties of the
spatial magnetic field distribution over the solar surface, we use a
technique developed by Higuchi. We have revealed the existence of three
families of self-similar contours corresponding to the sunspot umbra,
penumbra, and adjacent photosphere. The fractal coefficient has maxima
near the umbra—penumbra and penumbra—photosphere boundaries. The
fractal dependences of the longitudinal and transverse magnetic field
distributions are similar, but the fractal numbers themselves for the
transverse fields are larger than those for the longitudinal fields
approximately by a factor of 1.5. The fractal numbers decrease with
increasing mean magnetic field strength, implying that the magnetic
field distribution is more regular in active regions.

---------------------------------------------------------
Title: Current Helicity and Twist as Two Indicators of the Mirror
Asymmetry of Solar Magnetic Fields
Authors: Sokoloff, D.; Zhang, H.; Kuzanyan, K. M.; Obridko, V. N.;
Tomin, D. N.; Tutubalin, V. N.
2008SoPh..248...17S Altcode: 2008arXiv0802.3668S; 2008SoPh..tmp...19S
A comparison between the two tracers of magnetic field mirror asymmetry
in solar active regions - twist and current helicity - is presented. It
is shown that for individual active regions these tracers do not possess
visible similarity but averaging by time over the solar cycle, or by
latitude, reveals similarities in their behavior. The main property
of the data set is antisymmetry over the solar equator. Considering
the evolution of helical properties over the solar cycle we find
signatures of a possible sign change at the beginning of the cycle,
though more systematic observational data are required for a definite
confirmation. We discuss the role of both tracers in the context of
solar dynamo theory.

---------------------------------------------------------
Title: Quasi-Biennial Oscillations in the North - South Asymmetry
of Solar Activity
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2008SoPh..247..379B Altcode: 2008SoPh..tmp...13B
The north - south (N - S) asymmetry of solar activity is investigated
by using the data on coronal green-line brightness and total number and
total area of sunspots over the period of 1939 - 2001. Typical time
variations of the N - S asymmetry are found to be consonant in these
indices. Quasi-biennial oscillations (QBO) of solar activity are well
recognizable in the N - S asymmetry of the examined indices. Moreover,
the QBO are much better manifested in the N - S asymmetry of the
individual indices than in the original (N plus S) indices. The time
variations of relative QBO power are synchronous for the N - S asymmetry
of various solar activity indices whereas such a synchronization is
weaker for the indices themselves. It is revealed that the relative QBO
power found in the N - S asymmetry of the studied indices has a negative
correlation with the value of the N - S asymmetry itself. The findings
indicate that the N - S asymmetry should be regarded as a fundamental
phenomenon of solar activity similarly manifested in different activity
indices. These findings should be taken into account when any dynamo
theory of solar activity is constructed.

---------------------------------------------------------
Title: Manifestation of the solar global field changes in the
long-term cosmic rays modulation
Authors: Gushchina, R. T.; Belov, A. V.; Obridko, V. N.; Shelting,
B. D.; Balabin, Yu. V.
2008ICRC....1..473G Altcode: 2008ICRC...30a.473G
We discuss the improving of the semi-empirical model of cosmic ray (CR)
modulation proposed by us previously. In order to describe the long-term
variations with more complete reflection in the CR modulation of the
complex interaction of global and local solar magnetic fields it has
been proposed to introduce into the model the next characteristics:
the solar magnetic field polarity, the integral index iBr, the
partial indexes as well the tilt of the current sheet and the flare
index. The role of each index in the CR modulation is determined. For
the multi-parameter description of long-term CR variations by using
the integral index or one of four partial indexes the best fit for
1977-1999 period is obtained for the index iBr and the sector-odd index,
characterising an inclined dipole. It is proposed that decreasing
of density CR in minima of the last SA cycles (from cycle to cycle)
could be explained by decreasing of the zone-odd index and similar
decreasing of the vertical component of the total magnetic moment. The
discrepancy between the model and observations increases beginning from
the middle of 2000 therefore the problematic features of CR behavior
and modeling during the 23rd cycle are discussed.

---------------------------------------------------------
Title: Small-scale stochastic structure of the solar magnetic field
Authors: Ioshpa, B. A.; Obridko, V. N.; Chertoprud, V. E.
2007AstL...33..844I Altcode: 2007PAZh...33..941I
The small-scale (∼10″) stochastic properties of the solar magnetic
field B are analyzed in terms of the two-dimensional model of a fractal
Brownian process (the mean square of the difference between the field
strengths at two points separated by a distance D is proportional to D
2 H ). Digitized solar magnetograms with a 2″ resolution
are used to determine the standard deviation s of the magnetic field
and the exponents H at various levels of | B|. It has been established
that the transition from the background magnetic field to the fields
of an active region occurs near 25 50 G. A dependence of the exponent
H on the magnetic field amplitude has been derived. The exponent H
for the background magnetic field has been found to be much smaller
than that for the fields of an active region. The relationship of
the results obtained to certain fundamental properties of plasma in
a magnetic field is discussed.

---------------------------------------------------------
Title: Diagnostics of solar wind streams
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.
2007A&AT...26..501L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Asymmetry in the Inward-Outward Polarity in the Interplanetary
Magnetic Field
Authors: Asgarov, A. B.; Obridko, V. N.
2007SunGe...2...29A Altcode:
Distribution of the magnetic field of solar wind near the Earth
was investigated and compared with one expected from the classical
model. It is shown that the presence of two peaks in the distribution
of interplanetary magnetic field values, founded by Belov, Obridko
and Shelting (2006), is not an artefact of averaging but reflects
the real structure of magnetic field inside a sector. Moreover, the
magnetic field of the polarity corresponding to the leading sunspot
of the Northern Hemisphere is observed more frequently. With solar
activity rise the growth of both the module of a magnetic field and
the fields of each polarity separately were determined. The distance
between peaks increases from 6 nT to 10 nT. In alternate amplification
of peaks a quasi-22-year cycle was observed while in the intensity
of a field of each polarity there was revealed a 11-year cycle,
and in ratio of peaks to frequency of occurrence of zero values -
a quasi-2-year (2.6±0.3 year) cycle. Approximately in 25 % of all
cases the classical model is violated.

---------------------------------------------------------
Title: Magnetic cloud in the solar wind: A comparison with the
classical model
Authors: Askerov, A. B.; Obridko, V. N.
2007Ge&Ae..47..285A Altcode:
The solar wind magnetic field distribution near the Earth has been
studied and compared with the distribution anticipated according to the
classical model. It has been indicated that a two-hump distribution of
the IMF values discovered previously is not an artifact of averaging
but reflects the actual structure of the magnetic field within the
sector. In this case the magnetic field of polarity corresponding
to the leading spot in the Northern Hemisphere is encountered more
frequently. Not only the magnetic field magnitude but also the fields
of either polarity increase with increasing activity. The distance
between the peaks on the histogram of the magnetic field near the Earth
increases from 6 to 10 nT. The quasi-22-year, 11-year, and quasibiennial
(2.6 ± 0.3 years) cycles are observed in an alternate increase in
the peaks, in the strength of the fields of either polarity, and in
the ratio of the peaks to the occurrence frequency of zero values,
respectively. The classical model is violated in approximately 25%
of cases.

---------------------------------------------------------
Title: Some Structural Properties of Solar Magnetic Fields
Authors: Ioshpa, B.; Mogilevskii, E.; Obridko, V.
2007ASPC..368..245I Altcode:
We discuss some results of the study of spatial characteristics
of solar magnetic fields. The analysis is based on the magnetic
field data obtained with a new spectromagnetograph installed on the
IZMIRAN Tower Telescope (Fe I 6302.5 Å) (Kozhevatov et al., 2002),
the data of the MSFC solar vector magnetograph (Fe I 5250.2 Å)
and the data of longitudinal magnetic 96 m daily maps of SOHO/MDI
magnetograph (Ni I 6768 Å) downloaded through Internet. Our study was
directed in some different ways: the fractal properties of sunspots;
fractal properties of space distribution of the magnetic fields along
great distances comparable with the size of active regions or active
complexes; fractal properties of active and quiet regions as global
entities. To do it we used some different methods, particularly,
the well known method using the relation between the area and the
perimeter of magnetic field lines (see (Feder, 1988; Meunier, 1999;
Nesme-Ribes at al., 1996; Balke et al., 1993)) and technique developed
by Higuchi (1988), who applied it to the investigation of long time
series. Note also that magnetic structure in terms of the fractal
models was developed earlier in (Zelenyi &amp; Milovanov, 1991;
Milovanov &amp; Zelenyi, 1993; Mogilevskii, 1994; Mogilevskii, 2001;
Abramenko et al., 2002; Abramenko, 2005; Salakhudinova &amp; Golovko,
2005). The main results are: 1. Fractal analysis of sunspot
magnetic field indicated the existence of three families of self-similar
contour lines roughly belonging to the umbra, penumbra and the ambient
photosphere correspondingly. The greatest fractal dimension corresponds
to the regions of weakest fields (ambient photosphere), the least one
corresponds to the intermediate region (penumbra). 2. More detailed
analysis shows that the fractal coefficient has a maximum (about 1.50)
near the umbra--penumbra interface. 3. The global fractal numbers
of space distribution of magnetic field on solar surface is closely
connected with the mean absolute values of the longitudinal magnetic
field for this surface. The fractal numbers diminish with the rising
of mean magnetic field (from values about 2.0 for the relatively quiet
region to 1- 1.2 for very active regions). 4. The dependences
of fractal numbers of the space distribution of longitudinal and
transversal fields versus mean longitudinal field are similar by their
character but the fractal values for transversal field are higher than
the corresponding factor values for longitudinal field by factor about
1.5. This means that the distribution of transversal field along the
space is more chaotic than the distribution of longitudinal field.

---------------------------------------------------------
Title: A generalized polarity rule for solar magnetic fields
Authors: Obridko, V. N.; Shel'Ting, B. D.
2007ARep...51..339O Altcode: 2007AZh....84..380O
No abstract at ADS

---------------------------------------------------------
Title: To the problem of solar coronal heating
Authors: Badalyan, O. G.; Obridko, V. N.
2007AstL...33..182B Altcode: 2007PAZh...33..210B
We consider the adequacy of various solar coronal heating models. We
show that the correlation between the intensity of the coronal Fe XIV
530.5 nm green line and the calculated magnetic field strength in the
solar corona can be a useful tool for this purpose. We have established
this correlation for coronal structures and magnetic fields of large
spatial and temporal scales. The correlation found exhibits a strong
dependence on both solar cycle phase and heliolatitude. The efficiency
of a particular coronal heating mechanism is probably determined
by the relative area occupied by low and high loops (including open
structures). The direct current models based on slow field dissipation
(DC) and the wave models based on Alfvén and magnetosonic wave
dissipation (AC) are more efficient in the equatorial and polar zones,
respectively.

---------------------------------------------------------
Title: Occurrence of the 1.3-year periodicity in the large-scale
solar magnetic field for 8 solar cycles
Authors: Obridko, V. N.; Shelting, B. D.
2007AdSpR..40.1006O Altcode:
The data on solar magnetic fields since 1915 have been inferred from
H-alpha filament observations. We have used these data together with
direct magnetographic observations to study the cycle variation of
the large-scale field. Quasi-periodic oscillations with a period
of 1.3 years have been detected in the Sun during 8 cycles. They
are not present all the time, but are rather seen at maxima and in
declining phases of some cycles. No distinct correlation is revealed
with the height of the cycle and alternation of the even and odd
cycles. Oscillations with a period of 1.3 years are closely associated
with quasi-biennial oscillations (QBO) but, occasionally, they occur
in anti-phase.

---------------------------------------------------------
Title: Two Regularities in the Coronal Green-Line Brightness
Magnetic Field Coupling and the Heating of the Corona
Authors: Badalyan, O. G.; Obridko, V. N.
2006SoPh..238..271B Altcode: 2006SoPh..tmp...54B
To study the quantitative relationship between the brightness of the
coronal green line 530.5 nm Fe XIV and the strength of the magnetic
field in the corona, we have calculated the cross-correlation of
the corresponding synoptic maps for the period 1977 - 2001. The
maps of distribution of the green-line brightness I were plotted
using every-day monitoring data. The maps of the magnetic field
strength B and the tangential Bt and radial Br
field components at the distance 1.1 R⊙ were calculated
under potential approximation from the Wilcox Solar Observatory (WSO)
photospheric data. It is shown that the correlation I with the field
and its components calculated separately for the sunspot formation zone
±30° and the zone 40 - 70° has a cyclic character, the corresponding
correlation coefficients in these zones changing in anti-phase. In the
sunspot formation zone, all three coefficients are positive and have
the greatest values near the cycle minimum decreasing significantly by
the maximum. Above 40°, the coefficients are alternating in sign and
reach the greatest positive values at the maximum and the greatest
negative values, at the minimum of the cycle. It is inferred that
the green-line emission in the zone ±30° is mainly controlled by
Bt, probably due to the existence of low arch systems. In
the high-latitude zone, particularly at the minimum of the cycle,
an essential influence is exerted by Br, which may be a
manifestation of the dominant role of large-scale magnetic fields. Near
the activity minimum, when the magnetic field organization is relatively
simple, the relation between I and B for the two latitudinal zones
under consideration can be represented as a power-law function of the
type I ∝ Bq. In the sunspot formation zone, the power
index q is positive and varies from 0.75 to 1.00. In the zone 40 -
70°, it is negative and varies from −0.6 to −0.8. It is found
that there is a short time interval approximately at the middle of the
ascending branch of the cycle, when the relationship between I and B
vanishes. The results obtained are considered in relation to various
mechanisms of the corona heating.

---------------------------------------------------------
Title: Variations of the dipole magnetic moment of the sun during
the solar activity cycle
Authors: Livshits, I. M.; Obridko, V. N.
2006ARep...50..926L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: International Colloquium "Scattering and Scintillation in
Radio Astronomy" was held on June 19-23, 2006 in Pushchino, Moscow
region, Russia
Authors: Shishov, V. I.; Coles, W. A.; Rickett, B. J.; Bird,
M. K.; Efimov, A. I.; Samoznaev, L. N.; Rudash, V. K.; Chashei,
I. V.; Plettemeier, D.; Spangler, S. R.; Tokarev, Yu.; Belov, Yu.;
Boiko, G.; Komrakov, G.; Chau, J.; Harmon, J.; Sulzer, M.; Kojima,
M.; Tokumaru, M.; Fujiki, K.; Janardhan, P.; Jackson, B. V.; Hick,
P. P.; Buffington, A.; Olyak, M. R.; Fallows, R. A.; Nechaeva, M. B.;
Gavrilenko, V. G.; Gorshenkov, Yu. N.; Alimov, V. A.; Molotov, I. E.;
Pushkarev, A. B.; Shanks, R.; Tuccari, G.; Lotova, N. A.; Vladimirski,
K. V.; Obridko, V. N.; Gubenko, V. N.; Andreev, V. E.; Stinebring, D.;
Gwinn, C.; Lovell, J. E. J.; Jauncey, D. L.; Senkbeil, C.; Shabala, S.;
Bignall, H. E.; Macquart, J. -P.; Rickett, B. J.; Kedziora-Chudczer,
L.; Smirnova, T. V.; Rickett, B. J.; Malofeev, V. M.; Malov, O. I.;
Tyulbashev, S. A.; Jessner, A.; Sieber, W.; Wielebinski, R.
2006astro.ph..9517S Altcode:
Topics of the Colloquium: a) Interplanetary scintillation b)
Interstellar scintillation c) Modeling and physical origin of the
interplanetary and the interstellar plasma turbulence d) Scintillation
as a tool for investigation of radio sources e) Seeing through
interplanetary and interstellar turbulent media Ppt-presentations are
available on the Web-site: http://www.prao.ru/conf/Colloquium/main.html

---------------------------------------------------------
Title: Variation of the Dipole Magnetic Moment of the Sun during an
Activity Cycle
Authors: Livshits, I. M.; Obridko, V. N.
2006IAUJD...8E...6L Altcode:
Observations of large-scale solar magnetic fields (synoptic charts) and
the Sun as a star (general magnetic field) have been used to determine
the magnetic moment and direction of the dipole field for the past three
solar cycles. Both the magnitude of the magnetic moment and its vertical
and horizontal components proved to change regularly in the course of
a solar cycle never vanishing completely. A wavelet analysis has shown
that the amplitude of 27-day variations of the general magnetic field
of the Sun (GMF) is closely related to the magnitude of the horizontal
dipole. The sign reversal of the global dipole consists in the change
of inclination angle of its axis. The reversal process is not smooth
but occurs in steps lasting for 1-2 years. Before the reversal, the
dipole axis is precessing with respect to the solar rotation axis. Then,
it moves in the meridional plane to reach very low latitudes, where
it begins to shift significantly in longitude. These results are
discussed in the context of helioseismic inferences of the existence
of oscillations with a period of about 1.3 years and particularities
of the dynamo processes in the case of inclined rotator.

---------------------------------------------------------
Title: To the Problem of the Corona Heating
Authors: Badalyan, O. G.; Obridko, V. N.
2006IAUJD...3E..10B Altcode:
The adequacy of different models of the corona heating is discussed. The
correlation between the brightness of the coronal green line 530.5 nm
Fe XIV and the calculated strength of the magnetic field in the corona
is shown to be a very useful instrument to solve the problem. This
correlation manifests a very strong dependence both on the solar cycle
phase and heliolatitude. It seems reasonable that the effectiveness of
the mechanisms depends strongly on the relative area of low and high
(including open field) loops. The models based on slow field dissipation
(DC) are more effective in the low-latitude zone and the wave models
based on dissipation of Alfven waves (AC), in the high latitude zone.

---------------------------------------------------------
Title: Correlation between the near-Earth solar wind parameters and
the source surface magnetic field
Authors: Belov, A. V.; Obridko, V. N.; Shelting, B. D.
2006Ge&Ae..46..430B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Long-term variations of galactic cosmic rays in the past and
future from observations of various solar activity characteristics
Authors: Belov, A. V.; Gushchina, R. T.; Obridko, V. N.; Shelting,
B. D.; Yanke, V. G.
2006JASTP..68.1161B Altcode: 2006JATP...68.1161B
The previously proposed model of cosmic-ray (CR) modulation in the
heliosphere, which considers the relationship between long-term
CR variations and parameters of the solar magnetic field, has been
used to estimate the observed CR variations in the near-Earth space
with accuracy allowing their prediction. It is shown that there
are two possibilities: (1) to predict CR intensity for 1 6 months
by using the delay of CR variations relative to the solar-activity
(SA) effects and (2) to predict CR intensity for the next solar
cycle. In the second case, prediction of the global solar magnetic
field characteristics is crucial. Reliable long-term CR and SA data
are necessary in both cases. CR variations for the next solar cycle
are predicted by statistical method using solar magnetic field data
from two magnetographs (Stanford and Kitt Peak). The CR behavior during
centuries 17 20 has been reconstructed on the basis of a model relating
CR modulation to solar and geomagnetic activity indices.

---------------------------------------------------------
Title: The All-Russia conference on the Experimental and Theoretical
Basis of Forecasting Heliogeophysical Activity Organized by the Solar
Section of the Scientific Council of the Russian Academy of Ciences
on Astronomy and the Pushkov Institute of Terrestrial Magnetism,
Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences
(October 10 15, 2005, Troitsk)
Authors: Kuznetsov, V. D.; Obridko, V. N.
2006SoSyR..40..262K Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Calculation of the interplanetary magnetic field based on
its value in the solar photosphere
Authors: Obridko, V. N.; Shelting, B. D.; Kharshiladze, A. F.
2006Ge&Ae..46..294O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Cyclic variations in the differential rotation of the solar
corona
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2006ARep...50..312B Altcode:
The rotation of the solar corona is analyzed using the original
database on the brightness of the FeXIV 530.3 nm coronal green line
covering six recent activity cycles. The rate of the differential
rotation of the corona depends on the cycle phase. In decay phases,
there are only small differences in the rotation, which are similar
to that of a rigid body. The differences are more significant (though
less pronounced than in the photosphere) during rise phases, just
before maxima, and sometimes at maxima. The total rate of the coronal
rotation is represented as a superposition of two, i.e., fast and slow
modes. The synodic period of the fast mode is approximately 27 days
at the equator and varies slightly with time. This mode displays weak
differences in rotation and is most pronounced in the middle of decay
phases. The slow mode is manifested only at high latitudes during the
rise phases of activity, and displays a mean period of 31 days. The
relative contribution of each mode to the total rotational rate is
determined as a function of time and heliographic latitude. These
results indicate that the structure of the velocity field in the
convective zone must also vary with time. This conclusion can be
verified by helioseismology measurements in the near future.

---------------------------------------------------------
Title: Solar cycle according to mean magnetic field data
Authors: Obridko, V. N.; Sokoloff, D. D.; Kuzanyan, K. M.; Shelting,
B. D.; Zakharov, V. G.
2006MNRAS.365..827O Altcode: 2005MNRAS.tmp.1095O
To investigate the shape of the solar cycle, we have performed a
wavelet analysis of the large-scale magnetic field data for 1960-2000
for several latitudinal belts and have isolated the following
quasi-periodic components: ~22, 7 and 2 yr. The main 22-yr oscillation
dominates all latitudinal belts except the latitudes of +/-30° from
the equator. The butterfly diagram for the nominal 22-yr oscillation
shows a standing dipole wave in the low-latitude domain (|θ|&lt;=
30°) and another wave in the sub-polar domain (|θ|&gt;= 35°),
which migrates slowly polewards. The phase shift between these waves
is about π. The nominal 7-yr oscillation yields a butterfly diagram
with two domains. In the low-latitude domain (|θ|&lt;= 35°), the
dipole wave propagates equatorwards and in the sub-polar region,
polewards. The nominal 2-yr oscillation is much more chaotic than the
other two modes; however the waves propagate polewards whenever they
can be isolated. We conclude that the shape of the solar cycle
inferred from the large-scale magnetic field data differs significantly
from that inferred from sunspot data. Obviously, the dynamo models
for a solar cycle must be generalized to include large-scale magnetic
field data. We believe that sunspot data give adequate information
concerning the magnetic field configuration deep inside the convection
zone (say, in overshoot later), while the large-scale magnetic field is
strongly affected by meridional circulation in its upper layer. This
interpretation suggests that the poloidal magnetic field is affected
by the polewards meridional circulation, whose velocity is comparable
with that of the dynamo wave in the overshoot layer. The 7- and 2-yr
oscillations could be explained as a contribution of two sub-critical
dynamo modes with the corresponding frequencies.

---------------------------------------------------------
Title: Interplanetary Magnetic Field Calculated from Photospheric
Measurements
Authors: Obridko, V. N.; Belov, A. V.; Shelting, B. D.
2005ESASP.600E...5O Altcode: 2005dysu.confE...5O; 2005ESPM...11....5O
No abstract at ADS

---------------------------------------------------------
Title: Temporal Variations of the Solar Corona Rotation
Authors: Badalyan, O. G.; Obridko, V. N.; Kora, J. S.
2005ESASP.600E..50B Altcode: 2005dysu.confE..50B; 2005ESPM...11...50B
No abstract at ADS

---------------------------------------------------------
Title: Quasi-Biennial Oscillations in the N-S Asymmetry of Solar
Activity
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2005ESASP.600E.152B Altcode: 2005dysu.confE.152B; 2005ESPM...11..152B
No abstract at ADS

---------------------------------------------------------
Title: Some Fractal Properties of Solar Magnetic Fields
Authors: Ioshpa, B.; Mogilevskii, E.; Obridko, V.; Rudenchik, E.
2005ESASP.596E..68I Altcode: 2005ccmf.confE..68I
No abstract at ADS

---------------------------------------------------------
Title: Structure of Solar-Wind Streams at the Maximum of Solar
Cycle 23
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.; Filippov,
B. P.; Korelov, O. A.
2005AstL...31..546L Altcode:
We study the formation of solar-wind streams in the years of maximum
solar activity 2000 2002. We use observations of the scattering of radio
emission by solar-wind streams at distances of ∼4 60R S from the Sun,
data on the magnetic field structure and strength in the source region
(R ∼ 2.5R S), and observations with the LASCO coronagraph onboard
the SOHO spacecraft. Analysis of these data allowed us to investigate
the changes in the structure of circumsolar plasma streams during the
solar maximum. We constructed radio maps of the solar-wind transition,
transonic region in which the heliolatitudinal stream structure is
compared with the structure of the white-light corona. We show that
the heliolatitudinal structure of the white-light corona largely
determines the structure of the solar-wind transition region. We
analyze the correlation between the location of the inner boundary
of the transition region R in and the magnetic field strength on the
source surface |B R|. We discuss the peculiarities of the R in = F(|B
R|) correlation diagrams that distinguish them from similar diagrams
at previous phases of the solar cycle.

---------------------------------------------------------
Title: Quasibiennial Oscillations of the North-South Asymmetry
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
2005ARep...49..659B Altcode:
The north-south (N-S) asymmetry of the solar activity (A), which
reflects differences in the behavior of the northern and southern
hemispheres of the Sun, is studied using data on the brightness of the
coronal green line, the total number and area of sunspots, and the net
magnetic flux. The spatial and temporal distributions and correlations
between the A values represented by these indices are considered. The
characteristic time variations in A are similar for all the indices,
on both long and short time scales. Quasibiennial oscillations (QBOs)
can be traced in the asymmetries of all four indices. A detailed study
of the QBOs is carried out based on spectral-variation and wavelet
analyses. Long-term increases and decreases occur synchronously in
the asymmetries of various indices and are much more pronounced in A
than in the indices themselves. A negative correlation between the
power of the QBOs and the asymmetry of A can be traced; it is most
clearly manifest as a substantial diminishing of the QBOs during
the mid-1960s, which coincided with an especially strong increase in
A. Our analysis shows that the N-S asymmetry is probably a fundamental
property that controls the coupling and degree of coincidence between
the magnetic-field-generation mechanisms operating in the northern
and southern hemispheres.

---------------------------------------------------------
Title: Cyclic Variation in the Spatial Distribution of the Coronal
Green Line Brightness
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2005ARep...49..477B Altcode:
The spatial and temporal brightness distributions of the Fe XIV 530.3 nm
coronal green line (CGL) and cyclic variations of these distributions
are analyzed for a long time interval covering more than five 11-year
cycles (1943 2001). The database of line brightnesses is visually
represented in the form of a movie. Substantial restructuring of the
spatial distribution of the CGL brightness occur over fairly short
time intervals near the so-called reference points of the solar cycle;
such points can be identified based on various sets of solar-activity
indices. Active longitudes are observed in the CGL brightness over
1.5 3 yr. Antipodal and “alternating” active longitudes are also
detected. The movie can be used to compare the CGL brightness data with
other indicators of solar activity, such as magnetic fields. The movie
is available at http://helios.izmiran.rssi.ru/hellab/Badalyan/green/.

---------------------------------------------------------
Title: On a probable model of solar flares based on an `avalanche'
of self-organized criticality with energy and matter transport by
magnetohydrodynamic solitons
Authors: Mogilevskii, E. I.; Obridko, V. N.; Shilova, N. S.
2005A&AT...24...25M Altcode:
The problem of energy transport by magnetohydrodynamic (MHD) solitons
to the local region of a solar flare is considered within the framework
of a new concept on the nature of solar flares as an effect of the
unloading of matter and energy under self-organized criticality. The
high-resolution observations (±1?) by the TRACE spacecraft are
used. The characteristics of the small-scale discrete flare elements
are shown to correspond to the properties of MHD solitons. Therefore,
the above-mentioned concept represents conclusive evidence of the
fractal-cluster structure of the solar magnetized plasma.

---------------------------------------------------------
Title: Prediction of expected global climate change by forecasting
of galactic cosmic ray intensity time variation in near future based
on solar magnetic field data
Authors: Belov, A. V.; Dorman, L. I.; Gushchina, R. T.; Obridko,
V. N.; Shelting, B. D.; Yanke, V. G.
2005AdSpR..35..491B Altcode:
A method of prediction of expected part of global climate change caused
by cosmic ray (CR) by forecasting of galactic cosmic ray intensity time
variation in near future based on solar activity data prediction and
determined parameters of convection-diffusion and drift mechanisms is
presented. This gave possibility to make prediction of expected part
of global climate change, caused by long-term cosmic ray intensity
variation. In this paper, we use the model of cosmic ray modulation in
the Heliosphere, which considers a relation between long-term cosmic
ray variations with parameters of the solar magnetic field. The later
now can be predicted with good accuracy. By using this prediction,
the expected cosmic ray variations in the near Earth space also can
be estimated with a good accuracy. It is shown that there are two
possibilities: (1) to predict cosmic ray intensity for 1-6 months
by using a delay of long-term cosmic ray variations relatively to
effects of the solar activity and (2) to predict cosmic ray intensity
for the next solar cycle. For the second case, the prediction of the
global solar magnetic field characteristics is crucial. For both cases,
reliable long-term cosmic ray and solar activity data as well as solar
magnetic field are necessary. For solar magnetic field, we used results
of two magnetographs (from Stanford and Kitt Peak Observatories). The
obtained forecasting of long-term cosmic ray intensity variation we use
for estimation of the part of global climate change caused by cosmic
ray intensity changing (influenced on global cloudiness covering).

---------------------------------------------------------
Title: The relation of global magnetic solar field indices and solar
wind characteristics with long-term variations of galactic cosmic rays
Authors: Belov, A. V.; Gushchina, R.; Obridko, V. N.; Shelting, B. D.;
Yanke, V. G.
2005ICRC....2..235B Altcode: 2005ICRC...29b.235B
No abstract at ADS

---------------------------------------------------------
Title: Solar Magnetic Fields and the Intensity of the Green Coronal
Line
Authors: Badalyan, O. G.; Obridko, V. N.
2004ARep...48..678B Altcode:
Synoptic maps of the intensity of the λ530.5 nm FeXIV green coronal
line and maps of computed coronal magnetic fields for the period 1977
2001 are compared. For quantitative comparisons, the correlation
coefficients r for the correlation between these two parameters
at corresponding points of the synoptic maps are calculated. This
coefficient exhibits cyclic variations in the spot-formation zone,
±30° and the zone above 30° and is in antiphase in these two
zones. In the low-latitude zone, the correlation coefficient is
always positive, reaches its maximum at activity minimum, and strongly
decreases by activity maximum. Above 30°, r reaches maximum positive
values at activity maximum and then gradually decreases, passing
through zero near the beginning of the phase of activity minimum and
becoming negative during this phase. A Fourier analysis of r as a
function of time reveals a wavelike variation with a period close to
1.3 yr (known also from helioseismological data for the tachoclinic
region of magnetic-field generation), as well as a pronounced wave
with a period of about 5 yr. The latitude dependence of r seems to be
related to variations in the contributions from local, large-scale,
and global fields. Our analysis suggests an approach to studying the
complex problem of mechanisms for coronal heating.

---------------------------------------------------------
Title: Space-time distributions of the coronal green-line brightness
and solar magnetic fields
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2004A&AT...23..555B Altcode:
The space-time distribution of brightness of the Fe XIV, 530.3 nm
coronal green line and its cyclic variations are analysed for a long
time interval of more than five cycles (1943-2001). For this purpose
a special movie has been made. It is shown that a substantial spatial
reorganization of the coronal green-line brightness (CGLB) takes
a relatively short time and occurs close to the so-called reference
points of the cycle, as derived from the series of various solar
activity indices. The ‘active longitudes’ lasting for 1.5-3.0 years
are found to exist in the CGLB. The antipodal and ‘intermittent’
active longitudes are identified. For the time interval 1977-2001,
it has been corroborated that the CGLB is strongly influenced by the
magnetic field strength. An agreement is shown to exist between the
spatial structure on the CGLB synoptic charts and those of the magnetic
field strength. It is shown that the nature of the relationship between
the CGLB and the magnetic field strengths in the corona inside and
outside the sunspot formation zone differ significantly.

---------------------------------------------------------
Title: Reproducible Characteristics of the Solar Wind Acceleration
Authors: Lotova, N. A.; Vladimirskii, K. V.; Obridko, V. N.; Subaev,
I. A.
2004AstL...30..343L Altcode:
In experiments that were regularly carried out in 1999-2002 with
Pushchino radio telescopes (Russian Academy of Sciences), the study
of the radial dependence of the scattering of radio emission from
compact natural sources was extended to regions of circumsolar plasma
farther from the Sun. Based on a large body of data, we show that,
apart from the standard transonic acceleration region located at
distances of 10-40 Rsolar from the Sun, there is a region
of repeated acceleration at distances of 34-60 Rsolar
attributable to the equality between the solar wind velocity and the
Alfvenic velocity. The repetition in the trans-Alfvenic region of the
characteristic features of the radial stream structure observed in
the transonic region (the existence of a precursor, a narrow region of
reduced scattering that precedes a wide region of enhanced scattering)
suggests that the main characteristic features of the resonant
acceleration of solar wind streams are preserved up to distances of
the order of 60 Rsolar.

---------------------------------------------------------
Title: Multiparameter Computations of Solar Wind Characteristics in
the Near-Earth Space from the Data on the Solar Magnetic Field
Authors: Obridko, V. N.; Shelting, B. D.; Kharshiladze, A. F.
2004SoSyR..38..228O Altcode:
The solar wind parameters were analyzed using the concept which is
being developed by the authors and assumes the existence of several
systems of magnetic fields of different scales on the Sun. It was
demonstrated that the simplest model with one source surface and a
radial expansion does not describe the characteristics of the quiet
solar wind adequately. Different magnetic field subsystems on the Sun
affect the characteristics of the solar wind plasma in a different way,
even changing the sign of correlation. New multiparameter schemes were
developed to compute the velocity and the magnetic field components of
the solar wind. The radial component of the magnetic field in the solar
corona and the tilt of the heliospheric current sheet, which determines
the degree of divergence of field lines in the heliosphere, were taken
into account when calculating the magnetic field in the solar wind. Both
the divergence of field lines in the corona and the strength of the
solar magnetic field are allowed for in calculating the solar wind
speed. The suggested schemes provide a considerably higher computation
accuracy than that given by commonly used one-parameter models.

---------------------------------------------------------
Title: Relationship between the coronal green line brightness and
magnetic field strength
Authors: Badalyan, Olga G.; Obridko, V. N.
2004IAUS..223..371B Altcode: 2005IAUS..223..371B
The quantitative relation between the brightness of the coronal green
line 530.5 nm Fe XIV and the magnetic field strength is considered over
the 1977-2001 period. It is found that the correlation coefficients
between these two parameters calculated separately inside and outside
the sunspot formation zone pm 30^{circ} have cyclic variation and occur
in anti-phase. This suggests different mechanisms of formation of the
corona in the fields of small, medium, and large scales. These results
can be used for quantitative verification of the corona heating models.

---------------------------------------------------------
Title: Cyclic variations in distribution of the coronal green line
brightness and solar magnetic field
Authors: Badalyan, Olga G.; Obridko, V. N.; Sýkora, J.
2004IAUS..223...69B Altcode: 2005IAUS..223...69B
Cyclic variations of the coronal green line brightness (CGLB) are
investigated analysing a series of synoptic charts and a special
movie assembled of them, covering 1943-2001. Regular changes of
the large-scale CGLB distribution in dependence on the phase in
the solar cycle are presented. A quantitative relation between the
coronal green line intensity I and the total magnetic field strength
B is derived for the period 1977-2001; the B was calculated under
potential approximation. A simple exponential relation of type I
propto B^q was found to exist between the above two quantities. It is
shown that the q exponent may have opposite sign in the equatorial and
polar zones. During phases of the solar cycle maxima the I versus B
relation is much more complicated and cannot be expressed by such a
simple formula.

---------------------------------------------------------
Title: Magnetic Field Structure in Sunspots
Authors: Ioshpa, B. A.; Mogilevskii, E. I.; Obridko, V. N.; Rudenchik,
E. A.
2004IAUS..223..259I Altcode: 2005IAUS..223..259I
The paper deals with some structural characteristics of sunspot
magnetic fields.

---------------------------------------------------------
Title: Forecasting of galactic cosmic ray intensity based on solar
magnetic field data
Authors: Belov, A. V.; Dorman, L. I.; Gushchina, R. T.; Obridko,
V. N.; Shelting, B. D.; Yanke, V. G.
2004cosp...35.4184B Altcode: 2004cosp.meet.4184B
In Dorman (2004) it was made estimation of long-term cosmic ray
intensity variation in near future based on solar activity data
prediction and determined parameters of convection-diffusion and
drift mechanisms. In the present paper we use the model of cosmic
ray modulation in the Heliosphere which considers a relation between
long-term cosmic ray variations with parameters of the solar magnetic
field. The later now can be predicted with good accuracy. By using this
prediction, the expected cosmic ray variations in the near Earth space
also can be estimated with a good accuracy. It is shown that there are
two possibilities: 1) to predict cosmic ray intensity for 1-6 months by
using a delay of long-term cosmic ray variations relatively to effects
of the solar activity and 2) to predict cosmic ray intensity for the
next solar cycle. For the second case the prediction of the global
solar magnetic field characteristics is crucial. For both cases reliable
long-term cosmic ray and solar activity data as well as solar magnetic
field are necessary. For solar magnetic field we used results of two
magnetographs (Stanford and Kitt Peak). The obtained results we compare
with obtained by different method in Dorman (2004). References: Dorman
L.I. “Prediction of galactic cosmic ray intensity variation for few (up
to 10-12) years ahead on the basis of convection-diffusion/drift model
and data on solar activity”. Report on Session PSW1 of COSPAR-2004.

---------------------------------------------------------
Title: Regularities of formation of supersonic solar wind
Authors: Lotova, N.; Vladimirskii, K.; Obridko, V.; Subaev, I.
2004cosp...35.1244L Altcode: 2004cosp.meet.1244L
In the regular experiments carried out with the RAS radio telescopes
at Pushchino during 1999-2002, the study of the radial dependence of
scattering of compact natural radio sources was extended to remote
regions of the solar plasma environment. A vast statistical database
was accumulated. The analysis of the data shows that, in addition to
the well-known transonic acceleration region at a distance of 10-40 Rs
from the Sun, a secondary acceleration region exists at 34-60 Rs, being
due to the coincidence of the solar wind and Alfven velocities. The
stream in the transalfvenic region displays the same typical radial
structure as observed in the transonic region, i.e., the existence of
a "precursor" - a narrow band of reduced scattering preceding a wide
region of enhanced scattering. It implies that the main features of
resonance acceleration of the solar wind streams are conserved at the
distances of the order of 60 Rs.

---------------------------------------------------------
Title: Regularities of formation of supersonic solar wind
Authors: Lotova, N.; Vladimirskii, K.; Obridko, V.; Subaev, I.
2004cosp...35..352L Altcode: 2004cosp.meet..352L
In the regular experiments carried out with the RAS radio telescopes
at Pushchino during 1999-2002, the study of the radial dependence of
scattering of compact natural radio sources was extended to remote
regions of the solar plasma environment. A vast statistical database
was accumulated. The analysis of the data shows that, in addition to
the well-known transonic acceleration region at a distance of 10-40 Rs
from the Sun, a secondary acceleration region exists at 34-60 Rs, being
due to the coincidence of the solar wind and Alfven velocities. The
stream in the transalfvenic region displays the same typical radial
structure as observed in the transonic region, i.e., the existence of
a "precursor" - a narrow band of reduced scattering preceding a wide
region of enhanced scattering. It implies that the main features of
resonance acceleration of the solar wind streams are conserved at the
distances of the order of 60 Rs.

---------------------------------------------------------
Title: Prediction of expected global climate change by forecasting
of galactic cosmic ray intensity time variation in near future based
on solar magnetic field data
Authors: Belov, A. V.; Dorman, L. I.; Gushchina, R. T.; Obridko,
V. N.; Shelting, B. D.; Yanke, V. G.
2004cosp...35.3913B Altcode: 2004cosp.meet.3913B
In Dorman (2004) it was made estimation of long-term cosmic ray
intensity variation in near future based on solar activity data
prediction and determined parameters of convection-diffusion and drift
mechanisms. This gave possibility to made prediction of expected part
of global climate change, caused by long-term cosmic ray intensity
variation. In this paper we use the model of cosmic ray modulation in
the Heliosphere which considers a relation between long-term cosmic
ray variations with parameters of the solar magnetic field. The later
now can be predicted with good accuracy. By using this prediction,
the expected cosmic ray variations in the near Earth space also can
be estimated with a good accuracy. It is shown that there are two
possibilities: 1) to predict cosmic ray intensity for 1-6 months by
using a delay of long-term cosmic ray variations relatively to effects
of the solar activity and 2) to predict cosmic ray intensity for the
next solar cycle. For the second case the prediction of the global
solar magnetic field characteristics is crucial. For both cases reliable
long-term cosmic ray and solar activity data as well as solar magnetic
field are necessary. For solar magnetic field we used results of two
magnetographs (Stanford and Kitt Peak). The obtained by described method
prediction on long-term cosmic ray intensity variation we used for
estimation of expected part of global climate change caused by cosmic
rays. These results we compare with obtained by different method in
Dorman (2004). References: Dorman L.I. “Estimation of long-term cosmic
ray intensity variation in near future and prediction of expected global
climate change”. Report on Session D2.1/C2.2/E3.1 of COSPAR-2004.

---------------------------------------------------------
Title: Global Solar Magnetology and Reference Points of the Solar
Cycle
Authors: Obridko, V. N.; Shelting, B. D.
2003ARep...47..953O Altcode:
The solar cycle can be described as a complex interaction of
large-scale/global and local magnetic fields. In general, this approach
agrees with the traditional dynamo scheme, although there are numerous
discrepancies in the details. Integrated magnetic indices introduced
earlier are studied over long time intervals, and the epochs of the
main reference points of the solar cycles are refined. A hypothesis
proposed earlier concerning global magnetometry and the natural scale
of the cycles is verified. Variations of the heliospheric magnetic field
are determined by both the integrated photospheric i(B r )ph and source
surface i(B r )ss indices, however, their roles are different. Local
fields contribute significantly to the photospheric index determining
the total increase in the heliospheric magnetic field. The i(B r
)ss index (especially the partial index ZO, which is related to the
quasi-dipolar field) determines narrow extrema. These integrated indices
supply us with a “passport” for reference points, making it possible
to identify them precisely. A prominent dip in the integrated indices
is clearly visible at the cycle maximum, resulting in the typical
double-peak form (the Gnevyshev dip), with the succeeding maximum
always being higher than the preceding maximum. At the source surface,
this secondary maximum significantly exceeds the primary maximum. Using
these index data, we can estimate the progression expected for the 23rd
cycle and predict the dates of the ends of the 23rd and 24th cycles
(the middle of 2007 and December 2018, respectively).

---------------------------------------------------------
Title: Solar Wind Sources and Flow Structure Over the 1995-2000 Period
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirsky, K. V.
2003AIPC..679..110L Altcode:
Evolution of the large-scale stream structure of the solar wind flow
is studied in the main acceleration zone at 10 to 40 solar radii from
the Sun. Three independent sets of the experimental data were used:
observations of the radio wave scattering using the large radio
telescopes of the Lebedev Physical Institute, white solar corona
images obtained with the SOHO spacecraft, and solar magnetic field
strength computed from J.Wilcox Solar Observatory data. The positions
of the transonic region of the solar wind flow derived from the radio
astronomical observations data were used as a parameter reflecting
the intensity of the solar wind acceleration process. Correlation
studies of these data with the magnetic field strength in the solar
corona permit us to reveal several different types of the solar wind
streams. The 1995-2000 data show important changes in the solar corona
magnetic fields and corresponding changes of the solar wind flow.

---------------------------------------------------------
Title: The role of meridional circulation in generating the 22-year
solar cycle
Authors: Ivanov, E. V.; Obridko, V. N.; Shelting, B. D.
2003ESASP.535...37I Altcode: 2003iscs.symp...37I
The role of meridional circulation in generating the 22-year cycle
of solar magnetic fields and sunspots has been analysed. The proposed
model is based on the study of cyclic evolution of local and large-scale
fields: direction and duration of their heliolatitude drift, and phase
ratio of their maximum intensities. It is shown that the drift from the
equator to the poles occurs for 16-17 years, as well as the backward
drift from the poles to the equator at the base of the convection
zone. Thus, the total cycle of the meridional circulation of solar
magnetic fields is 32-34 years.

---------------------------------------------------------
Title: N-S asymmetry of solar activity and quasi-biennial oscillations
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
2003ESASP.535...63B Altcode: 2003iscs.symp...63B
Space-time distribution and mutual correlation of the N-S
asymmetry in various indices of solar activity are considered. It
is shown that changes in the N-S asymmetry variation both at short
and long time scales are consonant in all activity indices under
consideration. Quasi-biennial variations of the asymmetry index and
their space-time distribution are revealed and examined. The conclusion
can be drawn that the N-S asymmetry is a specific independent and very
promising tool for analysis of the solar activity variations.

---------------------------------------------------------
Title: Foreword (Solar variability as an input to the Earth's
environment)
Authors: Wu, T.; Obridko, V.; Schmieder, B.; Sykora, J.
2003ESASP.535D..17W Altcode: 2003iscs.sympD..17W
No abstract at ADS

---------------------------------------------------------
Title: Slow Solar Wind: Sources and Components of the Stream Structure
at the Solar Maximum
Authors: Vladimirsky, K. V.; Lotova, N. A.; Obridko, V. N.
2003AstL...29..629V Altcode:
We study the sources and components of the solar-wind spatial stream
structure at the maximum of the solar cycle 23. In our analysis, we
use several independent sets of experimental data: radio-astronomical
observations of scattered radiation from compact sources with the
determination of the distance from the Sun to the inner boundary of
the transonic-flow transition region (R_in); calculated data on the
magnetic-field intensity and structure in the solar corona, in the
solar-wind source region, obtained from optical measurements of the
photospheric magnetic-field intensity at the Stanford Solar Observatory
(USA); and observations of the white-light corona with the LASCO
coronograph onboard the SOHO spacecraft. We show that at the solar
maximum, low-speed streams with a transition region located far from
the Sun dominate in the solar-wind structure. A correlation analysis
of the location of the inner boundary R_in and the source-surface
magnetic-field intensity |B_R| on a sphere R = 2.5 R_solar is revealed
the previously unknown lowest-speed streams, which do not fit into
the regular relationship between the parameters R_in and |B_R|. In
the white-light corona, the sources of these streams are located near
the dark strip, a coronal region with a greatly reduced density;
the nonstandard parameters of the streams probably result from the
interaction of several discrete sources of different types.

---------------------------------------------------------
Title: The Global Cooperation in Solar-Terrestrial Physics as the
base for development of national programs in Russia: retrospect
and prospect.
Authors: Zaitzev, A.; Kozlov, A.; Obridko, V.
2003EAEJA....12781Z Altcode:
The International Geophysical Year (IGY, 1957-1958) was the global
coordination program that leads to develop of scientific collaboration
in the world. IGY was based on the previous experience gained during
International Polar Years. The most remarkable point for IGY was
the first Sputnik that opens the space era. Since that we count
direct outer space exploration. The combination of ground-based and
satellite observations lead to form of a new science Solar-Terrestrial
Physics. Since IGY we have the period of intensive development of STP
in Russia, which include many programs and projects. In 1957-1963
we gain two main results: the network of research institutes and
observatories as well as many space probes as COSMOS-49, COSMOS-321
etc. The leading role in developing of STP since IGY till nowadays
belongs to IZMIRAN (Institute of Terrestrial Magnetism, Ionosphere and
Radio Wave Propagation Russian Academy of Sciences). First director
of IZMIRAN Prof. Nikolay Pushkov (1903-1981) strongly advocate for
international cooperation and was one of the key figure in IGY. In May
2003 we celebrate his 100th birthday on special Symposium, which will be
held in IZMIRAN. During past 45 years it was built and sent into space
many space instruments including magnetometers, ionospheric sounders,
VLF sensors, etc. Last satellite is CORONAS-F , which launched at
July31, 2001 and successfully operate now. On the international
scene all experimental space research coordinated by COSPAR and
solar-terrestrial physics coordinated by SCOSTEP. In a new born Russia
the COSPAR partner is Space Research Institute and for SCOSTEP is
Sun-Earth Scientific Council. As the recent achievement in the area
of STP in Russia we might consider INTERBALL program. The progress in
STP based also on the usage of Internet as the data storage with remote
on-line access, with the system for search and exchange of information,
and with search engines in Russian language. At nowadays we have more
than 300 sites devoted to STP in Russian Internet among them as Space
Research Institute (www.iki.rssi.ru), IZMIRAN (www.izmiran.rssi.ru),
ISZF (www.iszf.irk.ru), NIIYAF (www.npi.msu.su). To refer a proposal
for IHY/IPY program we can confirm that in Russia we have a good
number of national projects, which might be considered as the starting
point. After governmental approval to take part in the IHY/IPY programs
Russian scientist will joint to the world community. From our personal
viewpoint we strongly advocate in favor to take part in IHY/IPY programs
on the base of previous experience. The part of this work was supported
by Russian Fund of Basic Research (grant # 02-07-90232).

---------------------------------------------------------
Title: Meridional Drift of Large-Scale Solar Magnetic Fields
Authors: Obridko, V. N.; Shelting, B. D.
2003ARep...47..333O Altcode:
It is shown that the meridional drift of large-scale fields starts
in the equatorial zone and continues over 15 16 yrs (16 17 according
to another estimate), i.e., during three fourths of the 22-year
cycle. There is an abrupt retardation of the drift at latitudes of 30°
50°, and a stagnation region where the drift rate does not exceed
several meters per second arises. The drift becomes rapid again at
higher latitudes. The stagnation region coincides with the area in which
the radial gradient of the rotational velocity is close to zero in the
convective zone. This drift is compared with helio-seismological data
on the rotation in the convective zone. A model taking into account
some elements of dynamo theory is proposed.

---------------------------------------------------------
Title: Integral Properties of Solar Active Regions
Authors: Chumak, O.; Obridko, V.; Zhang, H.; Ai, G.; Utrobin, V.;
Krasotkin, S.
2003A&AT...22..335C Altcode:
In the paper the results of investigations on ten solar active regions
are presented. The main results are as follows: firstly, the total
down-flow velocity exceeds the up-flow velocity by about two orders
of magnitude in all the active regions; secondly, no correlation was
found between the mean integral velocity flux and the mean integral
magnetic flux for all the active regions; thirdly, it was found that,
besides a direct correlation between the total sunspot area and the
total magnetic flux in active regions, occasionally there is an inverse
correlation between these parameters, and the inverse correlation
times often corresponded to the structural and topological rebuilding
of magnetic flux in the active regions; fourthly, a good correlation
was found between some parameters of integral fluxes (magnetic and
velocity) and X-ray flux variations.

---------------------------------------------------------
Title: Connections Between the White-Light Eclipse Corona and Magnetic
Fields over the Solar Cycle
Authors: Sýkora, J.; Badalyan, O. G.; Obridko, V. N.
2003SoPh..212..301S Altcode:
Observations of ten solar eclipses (1973-1999) enabled us to reveal and
describe mutual relations between the white-light corona structures
(e.g., global coronal forms and most conspicuous coronal features,
such as helmet streamers and coronal holes) and the coronal magnetic
field strength and topology. The magnetic field strength and topology
were extrapolated from the photospheric data under the current-free
assumption. In spite of this simplification the found correspondence
between the white-light corona structure and magnetic field organization
strongly suggests a governing role of the field in the appearance and
evolution of local and global structures. Our analysis shows that
the study of white-light corona structures over a long period of
time can provide valuable information on the magnetic field cyclic
variations. This is particularly important for the epoch when the
corresponding measurements of the photospheric magnetic field are
absent.

---------------------------------------------------------
Title: IZMIRAN Solar Spectromagnetograph
Authors: Kozhevatov, I. E.; Cheragin, N. P.; Kulikova, E. N.; Ioshpa,
B. A.; Obridko, V. N.; Rudenchik, E. A.; Nepomnyashchy, V. Yu.
2003ASPC..307...62K Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Quasi-biennial oscillations of the solar magnetic fields
Authors: Ivanov, E. V.; Obridko, V. N.; Shelting, B. D.
2002ESASP.506..847I Altcode: 2002svco.conf..847I; 2002ESPM...10..847I
Quasi-biennial oscillations (QBO) are mainly revealed in the structure
of large-scale solar magnetic fields (LSMF). In the medium-scale fields,
they are weak. QBO are well-pronounced in the time-latitude diagrams
and correlograms, as well as in the spectra of the source-surface
magnetic field sector structure. Thus, QBO are actually variations
of the equatorial dipole and quadrupole. QBO are also clearly seen in
the indices characterizing the asymmetry of the LSMF parameters. The
QBO intensity in LSMF changes with time, being maximum in the middle
of the 20th century. The relationship between QBO in LSMF
and the cycle reference points is investigated.

---------------------------------------------------------
Title: Meridional drifts of large-scale solar magnetic fields and
meridional circulation
Authors: Ivanov, E. V.; Obridko, V. N.; Shelting, B. D.
2002ESASP.506..851I Altcode: 2002svco.conf..851I; 2002ESPM...10..851I
The meridional drifts of local (LF) and large-scale (LSMF) solar
magnetic fields has been studied for the time interval 1960-2000. The
LSMF meridional drift velocity has been considered as a function of
latitude. Two modes have been discovered in the meridional poleward
drift of LSMF with the typical equator-to-pole travel times of 16-18 and
2-3 years. It is shown that the variation in the square values of the
solar field radial component on the time-latitude diagrams coincides
with the equatorward drift of local magnetic fields (LF). A shift by
5-5.5 years is observed in the intensity maxima of the global and local
fields. It is shown that the total period of meridional circulation
of solar plasma in the convection zone is ~22 years, i.e. is equal to
the Hale magnetic cycle.

---------------------------------------------------------
Title: New Izmiran solar spectromagnetograph
Authors: Kozhevatov, I. E.; Cheragin, N. P.; Ioshpa, B. A.; Kulikova,
E. H.; Obridko, V. N.; Rudenchik, E. A.
2002ESASP.506..951K Altcode: 2002svco.conf..951K; 2002ESPM...10..951K
A new solar spectromagnetograph for measuring the full magnetic-field
vector and line-of-sight velocities is described. A new version of a
polarization analyzer ensuring parallel measurements of six polarization
components of spectral lines is considered. The spectromagnetograph
allows the use of any algorithms for obtaining the magnetic fields
vector, in particular, the Babcock algorithm and the Fourier transform
technique. The sensitivity of the instrument for the longitudinal and
transverse magnetic field is 5-10 and 30-50 G, respectively, and ~10
m/s for the line-of-sight velocities.

---------------------------------------------------------
Title: Polarization in the 530.3nm emission line and coronal magnetic
field structure
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2002CoSka..32..175B Altcode:
To clarify the possible influence of the coronal magnetic field
on the degree of polarization p, direction of polarization β, and
line intensity Iλ measured during the 11 July 1991 total
solar eclipse, we have compared these quantities with different field
parameters. The structure of the coronal magnetic field on the eclipse
day was calculated using potential approximation. The relation of p and
Iλ as measured at 1.2 RSun from the centre of
the solar disk to the strength of the magnetic field and its different
components is discussed in detail. It is found that the points pertinent
to the large-scale coronal structures of different morphological
(physical) types (high-latitude streamers, bright equatorial regions,
regions in the vicinity of coronal holes, etc.) form isolated,
not overlapping clusters of points on the B -- p, B -- β and B --
log Iλ diagrams. Two classes of objects are distinct in
these diagrams. The first class comprises of high-latitude streamers
in which the degree of polarization increases with decreasing B. The
second class is represented by coronal condensations, moderately active
equatorial regions, and coronal holes. In the objects of this class, the
magnetic field strength is approximately three times as large as in the
streamers, and the degree of polarization depends only weakly on B. It
is shown that p, Iλ and β display a noticeable relationship
with the indices Q1 and Q2, which we introduced to
characterize the complexity (degree of inhomogeneity) of the magnetic
field at any given point in the solar corona. In fact, Q1
and Q2 represent the absolute and relative deviations of B
from its mean value measured in the neighbourhood of a given point. The
results of our investigation suggest that we are dealing with the direct
influence of the magnetic field on the generation of the polarized
radiation in the λ 530,3nm emission line. One can expect, therefore,
that the investigation of polarization characteristics would provide
a useful method for determining the magnetic field in the solar corona.

---------------------------------------------------------
Title: ASTRONOMY OF ANCIENT CIVILIZATIONS: The International
Conference of the European Society for Astronomy in Culture - SEAC,
Moscow, 2000
Authors: Obridko, V. N.; Potyomkina, T. M.; Lushnikova, A. V.;
Pustylnik, I. B.; Chepurova, V. M.
2002A&AT...21..279O Altcode:
Available from <A
href="http://taylorandfrancis.metapress.com/openurl.asp?genre=article&amp;issn=1055-6796&amp;volume=21&amp;issue=4&amp;spage=279">http://taylorandfrancis.metapress.com/openurl.asp?genre=article&amp;issn=1055-6796&amp;volume=21&amp;issue=4&amp;spage=279</A>

---------------------------------------------------------
Title: Three Types of Flows in the Structure of the Solar Wind
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.
2002ARep...46..339L Altcode:
An experimental study of the source and formation of large-scale
streams in the solar wind is presented. Radio-astronomical data from
1998 are compared with optical SOHO observations and solar coronal
magnetic fields calculated from Zeeman data obtained at the Wilcox
Observatory. A correlation between the geometry of the solar-wind
transition region and the strength of coronal magnetic fields is
revealed. For the moderate heliolatitudes studied, this correlation
divides into three branches corresponding to three types of coronal
magnetic-field structures: open structures with field lines escaping
into interplanetary space, closed structures with loop-like field
lines, and intermediate structures including both open and closed
configurations. High-speed streams of solar wind originate in regions
with open magnetic structures. These structures are connected with the
lateral lobes of streamers at moderate heliolatitudes. Low-speed flows
originate above closed magnetic structures, typical of the main bodies
of streamers. The lowest-speed solar-wind flows are not associated
with coronal streamer structures, and originate in coronal regions with
intermediate magnetic configurations simultaneously containing open and
closed field lines. In these regions, the white-light corona becomes
an extended and amorphous area with high luminosity, which stratifies
into a radial structure with narrow stripes at higher resolution.

---------------------------------------------------------
Title: Increase of the Magnetic Flux From Polar Zones of the sun in
the Last 120 Years
Authors: Makarov, V. I.; Tlatov, A. G.; Callebaut, D. K.; Obridko,
V. N.
2002SoPh..206..383M Altcode:
Lockwood, Stamper, and Wild (1999) argued that the average strength of
the magnetic field of the Sun has doubled in the last 100 years. They
used an analysis of the geomagnetic index «aa». We calculated the
area of polar zones of the Sun, Apz, occupied by unipolar
magnetic field on Hα synoptic magnetic charts, following Makarov
(1994), from 1878 to 2000. We found a gradual decrease of the annual
minimum latitude of the high-latitude zone boundaries, θ2m,
of the global magnetic field of the Sun at the minimum of activity from
53° in 1878 down to 38° in 1996, yielding an average decrease of 1.2°
per cycle. Consequently the area of polar zones Apz of the
Sun, occupied by unipolar magnetic field at the minimum activity, has
risen by a factor of 2 during 1878-1996. This means that the behavior
of the index «aa» and consequently the magnetic flux from the Sun
may be explained by an increase of the area of polar caps with roughly
the same value of the magnetic field in this period. The area of the
unipolar magnetic field at the poles (Apz) may be used as a
new index of magnetic activity of the Sun. We compared Apz
with the «aa», the Wolf number «W» and «A»* -index
(Makarov and Tlatov, 2000). Correlations based on `11-year' averages
are discussed. A temperature difference of about 1° between the
Maunder Minimum and the present time was deduced. We have found that
the highest latitude of the polar zone boundaries of the large-scale
magnetic field during very low solar activity reaches about 60°, cf.,
the Maunder Minimum. It is supposed that the θ2m-latitude
coincides with the latitude where ∂rω=0, with ω(r,θ)
being the angular frequency of the solar rotation. The causes of the
waxing and waning of the Sun's activity in conditions like Maunder
Minimum are discussed.

---------------------------------------------------------
Title: Direction of the coronal green line polarization as derived
from the eclipse measurements
Authors: Badalyan, O. G.; Obridko, V. N.; Sykora, J.
2002CoSka..32...49B Altcode:
Investigation of the polarization in the coronal FeXIV lambda
530.3 nm line is continued by exploiting the 11 July 1991 eclipse
observation. In this paper, we analyze the direction of the plane of
polarization represented by deviations of the magnetic vector from
the radial directions -- angle beta. The relation of this angle to the
other polarization charcteristics is discussed. It has been found that
beta is small in the coronal features characterized by a high degree
of polarization (streamers and coronal holes). With the decreasing
polarization (e.g., when the equatorial objects of enhanced activity are
considered) the magnitude of beta increases significantly. The extreme
values of beta are observed within the coronal features related to the
active regions in the photosphere. The distribution of beta in magnitude
is distinctly shifted from zero to positive values. This means that,
in the most part of the corona on July 11, 1991, the magnetic vector
deviates from radiality clockwise. In connection with the revealed
drastic discrepancy between the observed direction of the plane of
polarization and the generally accepted theoretical conceptions
(Badalyan et al., 2001; Badalyan, 2002), the obtained result may
be worth considering when developing a new theory of the origin of
polarized radiation in the coronal green line.

---------------------------------------------------------
Title: Secular and cycle variations of the IMF Bz component and some
associated geophysical effects
Authors: Obridko, V. N.; Golyshev, S.; Levitin, A. E.
2002ESASP.477..405O Altcode: 2002scsw.conf..405O
It is shown that the sign and amplitude of the annual mean Bz component
of the interplanetary magnetic field (IMF) conforms with the structure
of the large-scale solar magnetic field at the poles. Therefore, the
recurrence of geomagnetic activity is best pronounced in the cycles
when the polar field in the Sun is positive.

---------------------------------------------------------
Title: Zonal structure and meridional drift of large-scale solar
magnetic fields
Authors: Ivanov, E. V.; Obridko, V. N.
2002SoPh..206....1I Altcode:
Digitized synoptic charts of photospheric magnetic fields were analyzed
for the past 4 incomplete solar activity cycles (1969-2000). The
zonal structure and cyclic evolution of large-scale solar magnetic
fields were investigated using the calculated values of the
radial Br, |Br|, meridional Bθ,
|Bθ|, and azimuthal Bφ, |Bφ|
components of the solar magnetic field averaged over a Carrington
rotation (CR). The time-latitude diagrams of all 6 parameters and
their correlation analysis clearly reveal a zonal structure and two
types of the meridional poleward drift of magnetic fields with the
characteristic times of travel from the equator to the poles equal to
∼16-18 and ∼2-3 years. A conclusion is made that we observe two
different processes of reorganization of magnetic fields in the Sun
that are related to generation of magnetic fields and their subsequent
redistribution in the process of emergence from the field generation
region to the solar surface. Redistribution is supposed to be caused
by some external forces (presumably, by sub-surface plasma flows in
the convection zone).

---------------------------------------------------------
Title: Long-term variations of polar magnetic flux of the Sun and
terrestrial climate
Authors: Makarov, V. I.; Tlatov, A. G.; Callebaut, D. K.; Obridko,
V. N.
2002ESASP.477..563M Altcode: 2002scsw.conf..563M
We calculated the area of polar zones of the Sun, Apz, occupied by
unipolar magnetic field on Hα synoptic magnetic charts,
following Makarov (1994), from 1878 to 2000. We found a gradual decrease
of the annual latitude of the high-latitude zone boundaries of the
global magnetic field of the Sun at the minimum of activity from 53°
in 1878 down to 38° in 1996, yielding an average decrease of 1.2° per
cycle. We found that the area of polar zones of the Sun Apz has risen by
a factor of 2 during 1878-1996. The area of the unipolar magnetic field
at high-latitudes Apz may be used as a new index of magnetic activity of
the Sun. We compared Apz with the geomagnetic index and Wolf number. A
temperature difference of about 1.3° between the Maunder Minimum and
the present time was deduced. The causes of the waxing and waning of
the Sun's activity in conditions like Maunder Minimum are discussed.

---------------------------------------------------------
Title: The North-South asymmetry of solar activity
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
2002ESASP.477..201B Altcode: 2002scsw.conf..201B
In the present paper the North-South (N-S) asymmetry of four solar
activity indices is estimated and discussed. The coronal green line
intensity measurements, the Wolf numbers and the sunspot area data
- all of them were subjected to analysis over the 1943-1999 period,
together with the NSO/KP data on the total magnetic field flux measured
from 1975. The pair comparison of these four indices within different
zones of solar latitude allowed to reveal a number of features in
their mutual correlativness. As the coronal green line intensity as
the sunspot area display a long-termed wave in their N-S asymmetry -
about 40 years in duration. While during the first half of the interval
studied the N-hemisphere dominates (with a clear maximum around 1964-66)
then during the second half of the interval the activity measured over
the S-hemisphere prevails. Quasi-biennial variations were identified
both in the N-S asymmetry of the coronal green line brightness and
that of the total magnetic flux. The performed study indicates a close
relation between the global and local manifestations of solar activity,
which are governed by the magnetic fields of different scales.

---------------------------------------------------------
Title: Long-term Galactic Cosmic Rays Variations and Their Relation
With The Global Solar Magnetic Field Characteristics
Authors: Belov, A. V.; Gushchina, R. T.; Obridko, V. N.; Shelting,
B. D.; Yanke, V. G.
2002EGSGA..27.5528B Altcode:
The rigidity spectrum of CR variations is evaluated from data of
continuous monitor- ing of galactic cosmic rays (GCR), including ground
based observations of neutron and general ionizing components by the
network of CR stations, balloon and space- craft measurements of CR
intensity in the stratosphere and the near space, for the whole period
of the systematic CR ground based observations since 1953. Basing on
these results the multi-parametric model of large scale GCR modulation
by the solar activity in the heliosphere was elaborated (variations of
particle density with 10 GV rigidity were considered). Characteristics
of the global solar magnetic field on the so- lar wind source surface
are main parameters of the model. Analyzing the model results it is
possible to estimate a relative impact of each used indices accounting
its delay to the observed CR modulation. A special method was used to
account correctly the de- lay of solar-heliospheric characteristic
effect on CR. The effect reveals a dependence on primary cosmic ray
energy, an association with 11th and 22nd solar cycles. A solu- tion
of this problem allows calculate CR variations with better accuracy
and setup the problem of their prediction. A possibility of short-term
predictions of GCR intensity by observations of particular CR stations,
which data are available on Internet in real time, is considered in
this work. A quality of such a prediction is discussed.

---------------------------------------------------------
Title: The role of the solar magnetic field systems in modulating
the solar irradiance
Authors: Ivanov, E. V.; Obridko, V. N.
2002AdSpR..29.1951I Altcode:
Variations of indices that characterize various systems of the
large-scale solar magnetic field (LSSMF) - magnetic field multipoles
of different order, LSSMF energy index, index of the effective solar
multipole, etc.- are compared with variations of the solar irradiance
in different frequency ranges during 1978-1996. The role of the local
and global magnetic fields in modulating the solar irradiance is
investigated in various time intervals, in particular, in different
phases of the 11-year solar cycle.

---------------------------------------------------------
Title: Development the Internet - Resources in Solar-Terrestrial
Physics for the Science and Education
Authors: Zaistev, A.; Ishkov, V.; Kozlov, A.; Obridko, V.; Odintsov, V.
2002rict.confE..27Z Altcode:
Future development of research in the solar-terrestrial physics
(STP) will motivated by needs into fundamental knowledge and the
practical demands in the format of space weather. Public community
realized that outer space disturbances affects on the operation of
high technologies systems integrated into everyday life, so they
need into Internet resources of solar-terrestrial physics as the
open scientific and public domain. Recent achievements of STP lead
to burst of data sources and we have now many different types of
information available free in Internet: solar images from SOHO and
GOES-12 satellites, WIND and ACE interplanetary data, satellite
and ground-based magnetic field variations, aurora images in real
time, ionospheric data and many more. In this paper we present some
experience to establish in Russian language the open scientific and
public domain in Internet which can served for better understanding of
STP in wide scientific community and into the general public including
different media sources. Now we have more than one hundred sites which
present the STP data: Space Research Institute (www.iki.rssi.ru),
IZMIRAN (www.izmiran.rssi.ru), Institute of Solar-Terrestrial Physics
(www.iszf.irk.ru), Institute of Nuclear Physics in Moscow University
(http://alpha.npi.msu.su) &lt;A HREF="http://alpha.npi.msu.su"&gt;
Institute of Nuclear Physics in Moscow University &lt;/A&gt;) and
many more. Based on our own experience and our colleagues we decide
to create information resources in solar-terrestrial physics as the
open scientific and public domain. On this way the main directions
of our activity as follows: to produce the catalogues of resources
in Internet with detailed description of its content in Russian,
to publish the list of Russian institutes working in STP, to present
the biographical dictionary of Russian scientists in STP, to create
the interactive forum for discussion of latest scientific results, to
form the team of authors who willing to publish summarized analytical
papers on the STP problems, to establish the regular newsletter with
open circulation between professionals and people interested in STP,
and to provide the scientific coordination between Russian institutes
according rules of the road adopted by Solar-Terrestrial Scientific
Council. We strongly advocate in favor to construct such Internet
resources on native languages as it will served for national level due
to its basic funding source. On the other hand our experience might be
useful for other nations, as they are have the same aims. Our project
have one of the goal to establish a better public understanding of
STP through more open and wide public access to the latest scientific
results. The realization of this project is supported by Russian Fund of
Basic Research (grant N 02-07-90232) for period 2002-2004 and include
results also supported by RFBR before.

---------------------------------------------------------
Title: Relationship between the coronal shape and the magnetic field
topology during the solar cycle
Authors: Sýkora, J.; Badalyan, O. G.; Obridko, V. N.
2002AdSpR..29..395S Altcode:
We have observed ten solar eclipses during the 1973-1999 period, three
of them being recorded during the rising phase of the present solar
cycle 23. The observed shapes of the white-light corona are confronted
with the magnetic field topology, as calculated for the corresponding
eclipse days. A close relationship of the distinctive large-scale
coronal structures (coronal streamers, coronal holes, polar plumes,
etc.) with the calculated magnetic field structures and with the actual
position of the heliospheric current sheet (as derived for the source
surface at r = 2.5 R⊙) is evident. The found relations
suggest a new understanding of the coronal shape evolution during
the solar cycle. It is shown that "the isogausses" and the coronal
isophotes create two systems of mutually orthogonal curves. The nature
of this finding is also well confirmed by estimating of the magnetic
field strength inside the coronal holes observed during "our" eclipses.

---------------------------------------------------------
Title: Flow Sources and Formation Laws of Solar Wind Streams
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.; Bird,
M. K.; Janardhan, P.
2002SoPh..205..149L Altcode:
The large-scale stream structure of the solar wind flow is studied in
the main acceleration zone from 10 to 40 solar radii from the Sun. Three
independent sets of experimental data were used: radio astronomical
observations of radio wave scattering using the large radio telescopes
of the Lebedev Physical Institute; dual-frequency Doppler solar wind
speed measurements from the Ulysses Solar Corona Experiment during the
spacecraft's two solar conjunctions in summer 1991 and winter 1995;
solar magnetic field strength and configuration computed from Wilcox
Solar Observatory data. Both the experimental data on the position of
the transonic region of the solar wind flow and the solar wind speed
estimates were used as parameters reflecting the intensity of the solar
wind acceleration process. Correlation studies of these data with the
magnetic field strength in the solar corona revealed several types
of solar wind flow differing in their velocities and the location of
their primary acceleration region.

---------------------------------------------------------
Title: Global magnetic field of the Sun and long-term variations of
galactic cosmic rays
Authors: Belov, A. V.; Shelting, B. D.; Gushchina, R. T.; Obridko,
V. N.; Kharshiladze, A. F.; Yanke, V. G.
2001JASTP..63.1923B Altcode: 2001JATP...63.1923B
The paper deals with the relation of long-term variations of 10GV
galactic cosmic rays (GCR) to the global solar magnetic field and solar
wind parameters. This study continues previous works, where the tilt
of the heliospheric current sheet (HCS) and other solar-heliospheric
parameters are successfully used to describe long-term variations of
cosmic rays in the past two solar cycles. The novelty of the present
work is the use of the HCS tilt and other parameters reconstructed from
/Hα observations of filaments for the period when direct global solar
magnetic field observations were unavailable. Thus, we could extend the
GCR simulation interval back to 1953. The analysis of data for 1953-1999
revealed a good correlation (the correlation coefficient /&gt;0.88)
between the solar-heliospheric parameters and GCR in different cycles
of solar activity. Moreover, the approach applied makes it possible
to describe the behavior of cosmic rays in the epochs of solar maxima,
which could not be done before. This indicates both the adequacy of the
model and the reliability of the reconstructed global solar magnetic
field parameters.

---------------------------------------------------------
Title: Quasi-Biennial Oscillations of the Global Solar Magnetic Field
Authors: Obridko, V. N.; Shelting, B. D.
2001ARep...45.1012O Altcode:
Quasi-biennial oscillations (QBOs) can clearly be distinguished in
uniform series of data on the solar magnetic-field polarity derived
from Hα observations in 1915 1999. These have been proven to represent
oscillations of the global magnetic field of the Sun. This is verified
by spectral analyses executed using various methods: the QBOs are
clearly visible in low harmonics (l=1 3), but abruptly disappear for l=4
and higher. First and foremost, the QBOs are displayed in variations of
the sector structure of the large-scale magnetic field, demonstrating
that they correspond to variations of the horizontal multipoles.

---------------------------------------------------------
Title: Quasi-biennial oscillations of the solar global magnetic field
Authors: Shelting, B. D.; Obridko, V. N.
2001A&AT...20..491S Altcode:
This work continues the series of papers analyzing the nature
of the large-scale solar magnetic field (LSSMF) over a long time
interval (1915-1990). We used the data inferred from observations
of H filaments. SWAN and WAVELET analyses show that Quasibiennial
Oscillations are connected with the lowest multipoles, in other words,
with the global part of the LSSMF. For multipoles with number larger
than 4 the power of the spectrum in the range of 2-3 years decreases
abruptly. The LSSMF zonal and sectorial components (both odd and even)
were calculated and the Fourier spectra were obtained. This allowed
us to compare the amplitudes of different harmonics. Quasibiennial
oscillations are best pronounced in the odd sectorial structures. QBO
are absent at the cycle minima in the spectra based on the Stanford data
(i.e., with the field strength taken into account). Contrary to that,
QBO are of the same order over the entire time interval in the spectra
based on H data (i.e., where the field structure is emphasized).

---------------------------------------------------------
Title: The increase in the magnetic flux from the polar regions of
the Sun over the last 120 years
Authors: Makarov, V. I.; Obridko, V. N.; Tlatov, A. G.
2001ARep...45..746M Altcode:
The latitudes of the zonal boundaries of the global magnetic field of
the Sun are determined from the magnetic neutral lines on synoptic Hα
maps obtained during 1878 1999. The area of the polar zone occupied
by magnetic field of a single polarity at solar minima has doubled
over the last 120 years. This provides an explanation for the secular
increase in heliospheric characteristics, which differs from the
two-fold increase of the magnetic field strength predicted for this
period. The temporal variations of the magnetic flux from the polar
regions and their role in global changes of the Earth’s climate are
discussed in connection with secular variations in the structure of
the internal magnetic field of the Sun.

---------------------------------------------------------
Title: Flow Sources and Formation Laws of the Solar Wind Streams
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.; Bird,
M. K.; Janardhan, P.
2001hell.confE..18L Altcode:
The large-scale stream structure of the solar wind flow is studied in
the main acceleration zone from 10 to 40 solar radii from the Sun. Four
independent sets of experimental data were used: radio astronomical
observations of radio wave scattering using the large radio telescopes
of the Lebedev Physical Institute; dual-frequency Doppler solar wind
speed measurements from the Ulysses Solar Corona Experiment during
the spacecraft's solar conjunctions in summer 1991 and winter 1995;
solar magnetic field strength and configuration computed from Wilcox
Solar Observatory data; white-light coronagraph images obtained from
ground-based eclipse and SOHO observations. Both the experimental data
on the position of the transonic region of the solar wind flow and
the solar wind speed estimates were used as parameters reflecting the
intensity of the solar wind acceleration process. Correlation studies
of these data with the magnetic field strength in the solar corona
revealed several types of solar wind flow. Different types of streams
arise in coronal regions differing by their magnetic field strength
and structure. A total of four specific types, two of high-speed and
two of low-speed, were revealed.

---------------------------------------------------------
Title: Long-term variations of galactic cosmic rays and their relation
with the solar magnetic field parameters
Authors: Belov, A.; Gushchina, R.; Obridko, V.; Shelting, B.; Yanke, V.
2001ICRC...10.3911B Altcode: 2001ICRC...27.3911B
The paper deals with the relation of long-term variations of galactic
cosmic rays (CR) to the global solar magnetic field (GMF) and solar wind
(SW) parameters. This study continues the series of work, where the tilt
of the heliospheric current sheet (HCS) and other solarheliospheric
parameters are successfully used to describe long-term variations of
CR in the solar cycles. The novelty of the present work is the combined
use of the source surface magnetic field characteristics, including HCS
inclination, mean intensity of magnetic field and polarity of the global
magnetic field. We take into account both the direct effect of polarity
on CR variations and its effect on CR modulation related to the HCS tilt
changes. The combined use of different solar parameters allows us to
improve the model of long-term CR variations. The analysis of data for
1976-2000 has revealed a good correlation (the correlation coefficient
0.95) between the multi-parameter model and 10 GV galactic cosmic ray
behavior during long period, spanning several cycles of solar activity.

---------------------------------------------------------
Title: Rotation Characteristics of Large-Scale Solar Magnetic Fields
Authors: Obridko, V. N.; Shelting, B. D.
2001SoPh..201....1O Altcode:
The rotation characteristics of large-scale (global) magnetic fields
(GMF) and their relation to the activity of local fields (LMF) are
studied over a long time interval (1915-1996). The main results
are as follows. The GMF rotation rates and LMF activity vary in
anticorrelation. Both variations have similar periods (11 years and a
quasi-secular period of about 55-60 years), but are shifted relative
to each other by half an 11-year cycle. Therefore, (1) the GMF rotation
rate increases at the minimum of the 11-year cycle of LMF activity. (2)
The GMF rotation rate is faster in the less active hemisphere. (3)
The GMF rotation period slows down at the maximum of the secular LMF
activity (cycles 18 and 19).

---------------------------------------------------------
Title: The Structure of the Photospheric Velocity Field near Hα
Filaments
Authors: Ioshpa, B. A.; Obridko, V. N.
2001ARep...45..409I Altcode:
The velocity field of the plasma in the solar photosphere beneath
chromospheric Hα filaments is studied. Observations were conducted
in 1999 2000 using the magnetograph and tachometer of the tower
telescope of the Institute of Terrestrial Magnetism, Ionosphere, and
Radio Propagation, recently upgraded to improve both its sensitivity
and spatial resolution. The results confirm that, as noted earlier,
filaments are frequently found near velocity-inversion lines between
regions of upward and downward motion of solar material, and lie
predominantly above regions with upward motion of photospheric
material. This tendency is characteristic of both the stable filaments
of active regions and quiescent filaments far from active regions,
though it is more distinct for the former case. The upward motion of
photospheric material beneath filaments may play an important role in
supporting the filaments against gravity.

---------------------------------------------------------
Title: Brightness of the Coronal Green Line and Prediction for
Activity Cycles 23 and 24
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
2001SoPh..199..421B Altcode:
Cyclic variations of the mean semi-annual intensities Iλ
of the coronal green line λ530.3 nm are compared with the mean
semi-annual variations of the Wolf numbers W during the period of
1943-1999 (activity cycles 18-23). The values of Iλ in
the equatorial zone proved to correlate much better with the Wolf
numbers in a following cycle than in a given one (the correlation
coefficient r is 0.86 and 0.755, respectively). Such increase of the
correlation coefficient with a shift by one cycle differs in different
phases of the cycle, being the largest at the ascending branch. The
regularities revealed make it possible to predict the behaviour of
W in the following cycle on the basis of intensities of the coronal
green line in the preceding cycle. We predict the maximum semi-annual
W in cycle 23 to be 110-122 and the epoch of minimum between cycles 23
and 24 to take place at 2006-2007. A slow increase of Iλ
in the current cycle 23 permits us to forecast a low-Wolf-number cycle
24 with the maximum W∼50 at 2010-2011. A scheme is proposed on the
permanent transformation of the coronal magnetic fields of different
scales explaining the found phenomenon.

---------------------------------------------------------
Title: Sector Structure, Rotation, and Cyclic Evolution of Large-Scale
Solar Magnetic Fields
Authors: Ivanov, E. V.; Obridko, V. N.; Ananyev, I. V.
2001SoPh..199..405I Altcode:
Auto-correlation analysis was performed using digitized synoptic charts
of photospheric magnetic fields for the past three solar activity cycles
(1965-1994). The obtained correlograms were used to study the rotation
and the zonal-sector structure of large-scale solar magnetic fields
all over the observable region of heliolatitudes in various phases
of solar activity. It is shown that the large-scale system of solar
magnetic fields is rather complex and comprises at least three different
systems. One is a global rigidly rotating system. It determines the
cyclic variation of magnetic fields and is probably responsible for
the behavior of magnetic fields in the polar zones. Another is a
rigidly rotating 4-sector structure in the central (equatorial and
mid-latitude) zone. The third is a differentially rotating system
that determines the behavior of the LSSMF structure elements with a
size of ∼ 30-60° and less. This one is the most noticeable in the
central zone and absent in the polar zones. Various cyclic and rotation
parameters of the three field structures are discussed.

---------------------------------------------------------
Title: Large-Scale Magnetic Field and Sunspot Cycles
Authors: Makarov, V. I.; Tlatov, A. G.; Callebaut, D. K.; Obridko,
V. N.; Shelting, B. D.
2001SoPh..198..409M Altcode:
Hα magnetic synoptic charts of the Sun are processed for 1915-1999 and
the spherical harmonics are calculated. It is shown that the polarity
distribution of the magnetic field on Hα charts is similar to the
polarity distribution of the Stanford magnetic field observations
during 1975-1999. The index of activity of the large-scale magnetic
field A(t), representing the sum of the intensities of dipole and
octupole components, is introduced. It is shown that the cycle of
the large-scale magnetic field of the Sun precedes on the average by
5.5 years the sunspot activity cycle, W(t). This means that the weak
large-scale magnetic fields of the Sun do not result from decay and
diffusion of strong fields from active regions as it is supposed in
all modern theories of the solar cycle. On the basis of the new data
the intensity of the current solar cycle 23 is predicted and some
aspects of the theory of the solar cycle are discussed.

---------------------------------------------------------
Title: Cyclic Variations of CME Velocity
Authors: Ivanov, E. V.; Obridko, V. N.
2001SoPh..198..179I Altcode:
The semiannual mean CME velocities for the time interval of 1979-1989
have been analyzed to reveal a complex cyclic variation with a peak
at the solar cycle maximum and a secondary peak at the minimum of the
cycle. The growth of the mean CME width is accompanied by a growth
of the mean CME velocity. It is shown that the cyclic variations of
the mean CME velocity and the mean CME width are associated with the
cyclic variations of the large-scale magnetic field structure and that
the secondary peak of the semiannual mean CME velocity in 1985-1986 is
due to a significant contribution of fast CMEs with a width of ∼100°
at the minimum of the cycle. This peak is supposed to be due to the
increasing role of the global large-scale magnetic field system with a
characteristic size of cells of ∼ 70°-100° at the minimum of the
cycle and the respective particularities of the large-scale magnetic
field configuration in the corona.

---------------------------------------------------------
Title: Variations of the Solar-Wind Stream Structure in the Region
of Subsonic Flow during the 11-Year Solar Cycle
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskiĭ, K. V.
2000ARep...44..765L Altcode:
The large-scale stream structure of the solar wind near the Sun and its
evolution during the 11-year solar activity cycle are investigated. The
study is based on observations of scattering of the radiation from
compact natural radio sources at radial distances R≤14R S (R S is
the solar radius). Regular observations were conducted in 1981 1998
on the RT-22 and DKR-1000 radio telescopes of the Russian Academy of
Sciences at Pushchino, at λ=1.35 cm and 2.7 m, respectively. The radial
dependences of the interplanetary scintillations m(R) and the scattering
angle 2ϑ(R) are considered together with the structure of large-scale
magnetic fields in the solar corona at R=2.5R S. The entire range of
variations in the level of scattering and the associated heliolatitude
flow structures in the subsonic solar wind forms over the 11-year
solar cycle, as a direct result of the large-scale structure of the
evolving magnetic fields at the source of the solar-wind streamlines.

---------------------------------------------------------
Title: Seasonal Variations in Solar High-Energy Neutrino Flux and
Their Probable Source
Authors: Rivin, Yu. R.; Obridko, V. N.
2000SoSyR..34..501R Altcode: 2000AVest..34..501R
Cyclic variations of the solar neutrino flux (Homestake detector data)
have been analyzed both from season to season and within different
seasons and were compared with the corresponding variations of the
large-scale deep-layer solar magnetic field. The analysis revealed a
seasonal variation of the flux in the last twenty years with extremes
at equinox epochs. The mechanism of this variation can be due to the
asymmetry in magnitudes or to the twisting of the large-scale magnetic
fields in the southern and northern hemispheres of the Sun in the flux
modulation region.

---------------------------------------------------------
Title: Penetration of Coronal Magnetic Fields into Solar-Wind Streams
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.; Rushin, V.
2000AstL...26..539L Altcode:
The formation of solar-wind stream structure is
investigated. Characteristic features of the solar and coronal
magnetic-field structure, morphological features of the white-light
corona, and radio maps of the solar-wind transition (transonic) region
are compared. The solar-wind stream structure is detected and studied
by using radio maps of the transition region, the raggedness of its
boundaries, and their deviation from spherical symmetry. The radio
maps have been constructed from radioastronomical observations in
1995-1997. It is shown that the structural changes in the transition
region largely follow the changes occurring in regions closer to
the Sun, in the circumsolar magnetic-field structure, and in the
solar-corona structure. The correlations between the magnetic-field
strength in the solar corona and the location of the inner (nearest
the Sun) boundary of the transition region are analyzed. The distinct
anticorrelation between the coronal magnetic-field strength and the
distance of the transition region from the Sun is a crucial argument
for the penetration of solar magnetic fields into plasma streams far
from the Sun.

---------------------------------------------------------
Title: Amplitude and period of the dynamo wave and prediction of
the solar cycle
Authors: Dmitrieva, Isabella V.; Kuzanyan, Kirill M.; Obridko,
Vladimir N.
2000SoPh..195..209D Altcode:
The relation of the solar cycle period and its amplitude is a
complex problem as there is no direct correlation between these two
quantities. Nevertheless, the period of the cycle is of important
influence to the Earth's climate, which has been noted by many
authors. The present authors make an attempt to analyse the solar
indices data taking into account recent developments of the asymptotic
theory of the solar dynamo. The use of the WKB method enables us to
estimate the amplitude and the period of the cycle versus dynamo
wave parameters in the framework of the nonlinear development of
the one-dimensional Parker migratory dynamo. These estimates link
the period T and the amplitude a with dynamo number D and thickness
of the generation layer of the solar convective zone h. As previous
authors, we have not revealed any considerable correlation between
the above quantities calculated in the usual way. However, we have
found some similar dependences with good confidence using running cycle
periods. We have noticed statistically significant dependences between
the Wolf numbers and the running period of the magnetic cycle, as well
as between maximum sunspot number and duration of the phase of growth
of each sunspot cycle. The latter one supports asymptotic estimates of
the nonlinear dynamo wave suggested earlier. These dependences may be
useful for understanding the mechanism of the solar dynamo wave and
prediction of the average maximum amplitude of solar cycles. Besides
that, we have noted that the maximum amplitude of the cycle and the
temporal derivative of the monthly Wolf numbers at the very beginning
of the phase of growth of the cycle have high correlation coefficient
of order 0.95. The link between Wolf number data and their derivative
taken with a time shift enabled us to predict the dynamics of the
sunspot activity. For the current cycle 23 this yields Wolf numbers
of order 107±7.

---------------------------------------------------------
Title: Three types of solar wind flow
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.
2000A&A...357.1051L Altcode:
The origin of the large-scale stream structure of the solar wind
flow was studied using an experimental approach. Radio astronomy
data obtained in 1997 were compared with SOHO optical observations
of the solar corona and magnetic structures derived from the J.Wilcox
Observatory Zeeman data. A correlative relation was obtained between
the position of the transonic region of the solar wind and magnetic
field strength at the solar corona level. This relation falls into
three branches corresponding to three types of the magnetic field
structure: an open type with the field lines going in the interplanetary
space, closed loop-like type and intermediate type including both
configurations of field lines. The high-speed streams originate above
the open configurations, while closed and intermediate configurations
produce low-speed solar wind.

---------------------------------------------------------
Title: Large-Scale Solar Magnetic Field: Latitudinal Dependence
Authors: Obridko, V. N.; Shelting, B. D.
2000ARep...44..262O Altcode:
Large-scale solar magnetic fields in the latitude range 50° S 50°
N are analyzed in detail for a long time interval (1915 1990). We are
primarily concerned with the two types of large-scale fields forming
the two-and four-sector patterns on the Sun. The rotation parameters
of these structures are obtained for all latitudes considered. The
contribution of the two-sector structure grows and that of the
four-sector structure decreases toward high latitudes. The magnetic
field is activated simultaneously over a wide latitude range. Since
both magnetic-field systems exhibit quasi-rigid rotation, their
current systems must either be concentrated in a narrow latitude
range or be situated beneath the convection zone, where rotation is
only weakly differential. A period of about three years is manifest
in the difference between the rotation periods for the two types of
magnetic field. Physically, this may imply that these oscillations
are external with respect to any level, and there is some phase delay
due to their propagation from one level to another. We can conclude
with a fair degree of certainty that as the activity level rises,
the rotation speed decreases, and vice versa.

---------------------------------------------------------
Title: The Large-Scale Magnetic Field on the Sun: The Equatorial
Region
Authors: Obridko, V. N.; Shel'Ting, B. D.
2000ARep...44..103O Altcode:
The sector structure and variations in the large-scale magnetic
field of the Sun are studied in detail using solar magnetic-field
data taken over a long time interval (1915 1990). The two-sector and
four-sector structures are independent entities (i.e., their cross
correlation is very small), and they are manifest in different ways
during the main phases of the 11-year cycle. The contribution of the
two-sector structure increases toward the cycle minimum, whereas
that of the four-sector structure is larger near the maximum. The
magnetic-field sources determining the two-sector structure are
localized near the bottom of the convection zone. The well-known 2
3-year quasi-periodic oscillations are primarily associated with the
four-sector structure. The variations in the rotational characteristics
of these structures have a period of 55 60 years. The results obtained
are compared with the latest helioseismology data.

---------------------------------------------------------
Title: Coronal Holes (Recorded from 1943) - a Source of the
Solar-Induced Terrestrial Responses?
Authors: Sykora, J.; Badalyan, O. G.; Obridko, V. N.
2000ESASP.463...95S Altcode: 2000sctc.proc...95S
No abstract at ADS

---------------------------------------------------------
Title: Experimental confirmations of bioeffective effect of magnetic
storms.
Authors: Dmitrieva, I. D.; Khabarova, O. V.; Obridko, V. N.;
Ragulskaja, M. V.; Reznikov, A. E.
2000A&AT...19...67D Altcode:
The results of experiments for the determination of the influence of
geomagnetic field disturbances on a human organism are considered. We
used the method of electropuncture diagnostics by R. Voll for
this end. The method is based on measurements, of conductivity in
acupuncture points and is convenient because it allows us to estimate
deviations from the norm in the functioning of various organs in the
same units. The local A-index is used as an indicator of geomagnetic
field disturbance. The daily measurements of the group (27 persons) have
shown the presence of a synchronous mass response of inspected people on
magnetic storms. At first it is exhibited as a sharp (within 3-4 hours)
increase of conductivity of all the acupuncture points from normal
values, which corresponds to a maximum of adaptational capabilities
of an organism; and then a long duration (about 4 day) decrease of
conductivity that describes the depression of all organs and systems
of an organism. The reaction of adaptation on three magnetic storms of
identical intensity going with an interval per week was registered for
half of the inspected people. It was found that the duration of the
depression phase and the imbalance of an organism, intrinsic to this
phase, depends extremely on the wholeness of the organism (that is on
the power of ties between organs and coordination of their activity),
but not on the type of disease.

---------------------------------------------------------
Title: Analyses and modelling of coronal holes observed by
CORONAS-1. I. Morphology and magnetic field configuration
Authors: Obridko, V.; Formichev, V.; Kharshiladze, A. F.; Zhitnik,
I.; Slemzin, V.; Hathaway, D.; Wu, S. T.
2000A&AT...18..819O Altcode:
Two low-latitude coronal holes observed by CORONAS-1 in April and
June 1994 are analysed together with magnetic field measurements
obtained from Wilcox and Kitt Peak Solar Observatories. To estimate
the comparable temperature of these two coronal holes, the YOHKOH
observations are also utilized. Using this information, we have
constructed three-dimensional magnetic field lines to illustrate the
geometrical configuration of these coronal holes. The calculated
synoptic maps are used to determine the existence of closed and
open field regions of the hole. Finally, we have correlated the
characteristics of two coronal holes with the observed solar wind
speed. We found that the brighter coronal hole has a high-speed solar
wind, and the dimmer coronal hole has a low-speed solar wind.

---------------------------------------------------------
Title: Studies of the rotation periods of photospheric magnetic
fields in the 20th-22nd solar cycles
Authors: Anan'ev, I. V.; Obridko, V. N.
1999ARep...43..831A Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Velocity and Magnetic Field Structure in the Vicinity of
Hα Filaments
Authors: Ioshpa, B. A.; Obridko, V. N.
1999ESASP.448..497I Altcode: 1999mfsp.conf..497I; 1999ESPM....9..497I
No abstract at ADS

---------------------------------------------------------
Title: Long-Term Radio Scintillation Variations in the Circumsolar
Plasma
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirskii, K. V.; Bird,
M. K.; Pätzold, M.; Sieber, W.; Güsten, R.; Korelov, O. A.
1999SoPh..189..387L Altcode:
Long-term scintillation measurements of the solar wind formation zone
at solar elongations ranging from 1°-8° (Sun impact parameters: 4-30
R⊙) were recorded using the water maser source IRC-20431
at the wavelength λ=1.35 cm during its annual solar occultations
in December 1981-1998. Dramatic changes in the spatial dependence
of the scintillation index were recorded over the course of the
11-year solar cycle. Markedly diminished scattering, attributed to
a pronounced heliolatitude effect, was observed at the closest solar
approach distances in the years around solar activity minimum. From
parallel investigations of the solar magnetic field structure it was
determined that the field strength at the source of the solar wind
streamlines is the governing factor for the solar wind acceleration
process. Particularly apparent in the scintillation data during solar
activity minimum is the increasing role of the polar coronal holes
with their associated open magnetic field structure. The dependence
of the solar scattering intensity on heliolatitude fades in the years
of high solar activity as the level of scintillations increases at
polar latitudes.

---------------------------------------------------------
Title: Relation between the green-line polarization of the solar
corona and corona magnetic fields
Authors: Badalyan, O. G.; Obridko, V. N.; Sykora, J.
1999ARep...43..767B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Structure and magnetic field of the July 11, 1991 eclipse
corona from the solar cycle viewpoint
Authors: Sykora, J.; Badalyan, O. G.; Obridko, V. N.; Pinter, T.
1999CoSka..29...89S Altcode:
A set of the white-light images was used to perform relative photometry
of the July 11, 1991 eclipse corona. The observed global form of that
day corona was found to be rather unusual for the actual solar cycle
phase. In this relation, the recently calculated coronal magnetic field
structures and strengths are presented and discussed. An idea on the
close relation between the observed global form of the corona and the
presence of the individual coronal structures around the solar limb, on
the one hand, and the calculated magnetic field topology and strength,
on the other hand, is supported and found to be of great interest.

---------------------------------------------------------
Title: Long-term variations of the solar-geomagnetic correlation,
total solar irradiance, and northern hemispheric temperature
(1868-1997)
Authors: Kishcha, P. V.; Dmitrieva, I. V.; Obridko, V. N.
1999JASTP..61..799K Altcode: 1999JATP...61..799K
Time series for annual means of sunspot numbers, aa-indices of
geomagnetic activity and annual numbers of 3-h time intervals
with different values of aa-indices (aa&lt;=4 and aa&gt;=30) from
1868 to 1997 have been examined by the method of running-window
cross-correlation analysis. It has been found that the solar-geomagnetic
correlation varies over time. In particular, long-term variations of the
23-year running correlation appear to have a quasi periodicity of about
40-50 years, superposed on a linear trend, where the trend describes
a general decrease of the 23-year running-window correlation between
1868 and the present. Long-term variations of the solar-geomagnetic
correlation may result from the quasi-periodic fluctuations of
the time lag of geomagnetic indices relative to sunspot numbers,
superposed on an upward linear trend of time lag. Secular variations
of the northern hemisphere land-air surface temperature anomalies
and two solar indices that are potential proxy measures for the total
solar irradiance (i.e., the length of the sunspot cycle and the Hoyt
and Schatten (Hoyt, D.V., Schatten, K.V., 1993. Journal of Physical
Research 98, 18,895-18,906.) composite index) have been compared with
the long-term variations of the solar-geomagnetic correlation. The
extremum points (points where the derivative vanishes to zero) of these
variations are found to occur contemporaneously during the periods
of low solar-geomagnetic correlation, suggesting, perhaps, that the
long-term variations of solar-geomagnetic correlation are due to some
long-term processes on the Sun and that they have a measurable effect
on the Earth.

---------------------------------------------------------
Title: North-South asymmetry of the magnitude of large-scale solar
magnetic fields
Authors: Rivin, Yu. R.; Obridko, V. N.
1999ARep...43..479R Altcode:
An annual variation with its extrema at the equinoxes has been detected
in photospheric measurements of the magnitude of the large-scale solar
magnetic field near the equator. It is proposed that a hemispheric
asymmetry in the magnitudes of the large-scale magnetic fields in
the region of generation of the quadrupole field is responsible for
this variation.

---------------------------------------------------------
Title: Structure and Cyclic Variations of Open Magnetic Fields in
the sun
Authors: Obridko, V. N.; Shelting, B. D.
1999SoPh..187..185O Altcode:
The structure and variations of open field regions (OFRs) are analyzed
against the solar cycle for the time interval of 1970-1996. The cycle
of the large-scale magnetic field (LSMF) begins in the vicinity of
maximum Wolf numbers, i.e. during the polar field reversal. At the
beginning of the LSMF cycle, the polar and mid-latitude magnetic
field systems are connected by a narrow bridge, but later they evolve
independently. The polar field at the latitudes above 60° has a
completely open configuration and fills the whole area of the polar
caps near the cycle minimum of local fields. At this time, essentially
all of the open solar flux is from the polar caps. The mid-latitude
open field regions (OFRs) occur at a latitude of 30-40° away from
solar minimum and drift slowly towards the equator to form a typical
'butterfly diagram' at the periphery of the local field zone. This
supports the concept of a single complex - 'large-scale magnetic field
- active region - coronal hole'. The rotation characteristics of OFRs
have been analyzed to reveal a near solid-body rotation, much more
rigid than in the case of sunspots. The rotation characteristics are
shown to depend on the phase of the solar cycle.

---------------------------------------------------------
Title: Phenomenology of coronal mass ejections
Authors: Mogilevsky, E. I.; Obridko, V. N.; Shilova, N. S.
1999ARep...43..255M Altcode:
An attempt to describe the phenomenology of solar coronal mass ejections
(CMEs) at all wavelength bands is undertaken. The development of
several typical CMEs in 1996 and 1997 is considered in detail. Among the
properties revealed, we especially emphasize (1) the presence of initial
eruption prominences that are relatively distant from each other, (2)
the development of CMEs from two eruption sites, and (3) the connection
of CMEs with structural evolution, i.e., large-scale solar-activity
complexes. In addition to determining the basic properties of CMEs,
we compare scenarios for CMEs and flares and search for common features
in the natures of these phenomena, which have very different temporal
and spatial scales. A qualitative model for the above phenomena is
put forward.

---------------------------------------------------------
Title: Time variations of solar neutrino. The main arguments pro
and some inferences
Authors: Rivin, Yu. R.; Obridko, V. N.
1999astro.ph..2074R Altcode:
The paper contains some arguments in support of time variations of
the high-speed flux of solar neutrino

---------------------------------------------------------
Title: Relevance of CME to the Structure of Large-Scale Solar
Magnetic Fields
Authors: Ivanov, E. V.; Obridko, V. N.; Nepomnyashchaya, E. V.;
Kutilina, N. V.
1999SoPh..184..369I Altcode:
The relevance of the occurrence rate and location of CME events to two
main systems (giant and supergiant) of the large-scale solar magnetic
field structure has been investigated. The clustering of CME events
and solar flares toward the neutral line of the global field system
(neutral line of the source surface field) corroborates the finding
by Hundhausen that CME locations track the heliomagnetic equator. A
good correlation has been revealed between the CME occurrence rate
and variations of the index of the effective solar multipole, that
characterizes the typical scale of the global solar magnetic field. The
CME rate exhibits sharp jumps/decreases when the index of the effective
solar multipole passes through n=4. The observations of X-ray 'blow-out'
effects have been analyzed as probable manifestations of CMEs on
the disk and have been compared with the large-scale magnetic field
structure. As shown by the analysis, the X-ray arcades straddle the
neutral line and occur, or at least tend to occur, where the neutral
line exhibits a sharp bend. A conclusion is made that CME events are
caused by interaction of two large-scale field systems, one of them
(the global field system) determining the location of CMEs and another
(the system of closed magnetic fields) their occurrence rate.

---------------------------------------------------------
Title: Structure of the Heliospheric Current Sheet derived for the
interval 1915 -1916
Authors: Obridko, V. N.; Shelting, B. D.
1999SoPh..184..187O Altcode:
Hα observations of solar large-scale fields were used to reconstruct
the heliosphere structure for the time interval of 1915-1996. A special
method of polar correction was developed. The expansion coefficients
in Legendre polynomials were calculated. An atlas of the heliosphere
structure was compiled. `Inferred' strength of the polar and equatorial
field in 1915-1996 years was calculated. Cyclic variations of the
polar field and the number of polar plages were compared to show a
satisfactory agreement. The q parameter, characterizing the divergence
of the polar plumes in the epochs of the solar minimum, was calculated
and its quasi-periodic behaviour with a period of the order of 70
years was revealed. Our calculations were tentatively compared with
the interplanetary magnetic field structure.

---------------------------------------------------------
Title: Relationship between the green-line corona polarization and
coronal magnetic fields
Authors: Badalyan, O. G.; Obridko, V. N.; Sýkora, J.
1999ASSL..243..373B Altcode: 1999sopo.conf..373B
No abstract at ADS

---------------------------------------------------------
Title: Variations of the total solar radiation flux and magnetic
field with 2 to 10-day periods
Authors: Obridko, V. N.; Anan'ev, I. V.; Arlt, K.; Pflug, K.
1998ARep...42..534O Altcode:
A joint spectral analysis of cyclic variations of the total solar
radiation flux and magnetic field is presented. In the period range
from 2-10 days, the solar-constant and magnetic-field spectra are
determined not only by harmonics of the solar rotation, but also by the
structure of active regions and the lifetime and variation time scales
for magnetic fields on various scales. Up to a period of nine days,
all harmonics have a rotational nature. Beginning from a period of seven
days, the spectra are determined by variations of the solar activity.

---------------------------------------------------------
Title: Effects of the solar magnetic field on the solar wind stream
structure
Authors: Lotova, N. A.; Obridko, V. N.; Vladimirsky, K. V.
1998ARep...42..553L Altcode:
We carry out a comprehensive analysis of experimental data on the solar
surface magnetic field and the scattering properties of the circumsolar
plasma in the subsonic region at R ~= (4-12) R_solar to study the forma-
tion mechanism of the solar wind stream structure. We use the data on
the radial dependence of the scattering angle of radio waves obtained in
1985-1996 during radio occultation experiments in the circumsolar plasma
with the source 3C 144. These data are compared with the helio-latitude
structure of the solar surface magnetic field. We have established
that the typical deviations of the relation between the scattering
and the radial distance from a regular power law and the decrease in
scattering at small distances from the Sun correlate with the open
structure of magnetic field lines and with the penetration of the
fields from coronal holes and other local sources in the plasma streams.

---------------------------------------------------------
Title: Natural Disasters and Solar Activity (Based on Chronicles
and Annals)
Authors: Dmitrieva, I. V.; Zaborova, E. P.; Obridko, V. N.
1998A&AT...17...29D Altcode:
The chronicle data on natural phenomena observed in Europe and in
Russia from the year 0 to 1600 were analysed. We compared droughts,
cold-spells, epidemics, epizootics and famines with solar activity
data (sunspots visible to the naked eye). As shown by the analysis,
the maximum occurrence of droughts, epidemics and epizootics either
coincides with the sunspot maximum or is observed in the growth phase
of solar activity. For very cold winters the correlation with solar
activity was not so pronounced. As to famines, they do not reveal
noticeable correlation with any natural factors.

---------------------------------------------------------
Title: White-light polar plumes from three 'minimum-like' solar
eclipses
Authors: Sykora, J.; Ambrovz, P.; Minarovjech, M.; Obridko, V. N.;
Pinter, Th.; Rybansky, M.
1998ESASP.421...79S Altcode: 1998sjcp.conf...79S
No abstract at ADS

---------------------------------------------------------
Title: Evolution of the Filament/CH/Magnetic Field Complex
Authors: Ioshpa, B. A.; Mogilevsky, E. I.; Obridko, V. N.
1998ASPC..150..393I Altcode: 1998npsp.conf..393I; 1998IAUCo.167..393I
No abstract at ADS

---------------------------------------------------------
Title: Some Investigations of Coronal Holes and Large-scale Solar
Magnetic Fields Using Coronas, Yohkoh, SOHO and Ground-based Data
(invited)
Authors: Obridko, Vladimir N.
1998asct.conf...41O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Analyses and Modeling of Coronal Holes Observed by Coronas-I:
II. MHD Simulation
Authors: Wang, A. H.; Wu, S. T.; Dryer, M.; Hathaway, D.; Obridko,
V.; Fomichev, V.; Kharshiladze, A. F.; Zhitnik, L.; Slemzin, V.
1998asct.conf..273W Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Variations of Solar Irradiance, 10.7 CM Radio Flux, He I 10830
Angstroms Equivalent Width and Global Magnetic Field Intensity and
Their Relation to Large-Scale Solar Magnetic Field Structure
Authors: Ivanov, E. V.; Obridko, V. N.; Ananyev, I. V.
1998SoPh..177..217I Altcode:
Variations of total solar irradiance, 10.7 cm radio emission, the Hei
10830 Ú equivalent width and the solar magnetic field flux measured
for the entire Sun are compared with variations of the energy index of
the global solar magnetic field and the index of the effective solar
multipole for years 1979-1992. It is shown that photospheric radiation
and that generated in the upper chromosphere and corona display
different relationships with the global magnetic field of the Sun, and
that interaction between the magnetic field and the solar irradiance
is much more complicated than the traditional blocking effect.

---------------------------------------------------------
Title: Solar activity-climate coupling and atmospheric circulation
Authors: Dmitrieva, I. V.; Zaborova, R. P.; Obridko, V. N.
1998A&AT...16..133D Altcode:
Long series of various climate parameters and their relation to solar
activity have been analysed. A sudden variation in the character of
the solar activity-climate coupling has been revealed during the change
of the global circulation epochs in the North hemisphere.

---------------------------------------------------------
Title: Cyclic Variation of the Solar Wind Velocity and Energy of
the Large-Scale Magnetic Field of the Sun
Authors: Shelting, Bertha D.; Obridko, Vladimir N.
1998asct.conf..447S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Variations of Solar Irradiance, 10.7 CM Radio Flux, He I
10830 Å Equivalent Width and Global Magnetic Field Intensity and
their Relation to Large-Scale Solar Magnetic Field Structure
Authors: Ivanov, E. V.; Obridko, V. N.; Ananyev, I. V.
1998sers.conf..217I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Relation of the CME Rate to the Large-scale Solar Magnetic
Fields Structure
Authors: Ivanov, Evgeny V.; Obridko, Vladimir N.; Shelting, Bertha D.
1998asct.conf..365I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Structure and Cyclic Variations of Open Magnetic Fields in
the Sun
Authors: Obridko, V. N.; Shelting, B. D.
1997ESASP.415..357O Altcode: 1997cpsh.conf..357O
No abstract at ADS

---------------------------------------------------------
Title: International Solar Cycle Studies - ISCS (1998-2002)
Authors: Obridko, V. N.
1997ESASP.415..267O Altcode: 1997cpsh.conf..267O
No abstract at ADS

---------------------------------------------------------
Title: Large-Scale Magnetic Field Structures and Coronal Holes on
the Sun
Authors: Mogilevsky, E. I.; Obridko, V. N.; Shilova, N. S.
1997SoPh..176..107M Altcode:
This paper is aimed at establishing the relationship between
the large-scale magnetic fields (LSMF), coronal holes (CH), and
active regions (AR) in the Sun. The LSMF structure was analyzed
by calculating the vector photospheric magnetic field under a
potential approximation. Synoptic maps were drawn to study the
distribution of the B⊥ field component and to isolate
regions where the open field lines of the unipolar magnetic field
are most radial. These are the sites of occurrence of X-ray and Hei
10830 Å coronal holes detected from the SXT/Yohkoh images. It is
shown that coronal holes are usually located in LSMF regions with a
typical pattern of divergentB⊥ vectors and a so-called
`saddle' configuration.B⊥ vectors from the `conjugate'
(spaced by 90°) coronal holes converge towards the active regions
between CH. Variations in AR distort coronal holes and change their
boundaries. This implies that the energy regime in CH depends on the
energy supply from the active region. The LSMF structure is more
stable than coronal holes, remaining practically unchanged during
tens of rotations of the Sun. Thus, a peculiar magnetically coupled
system of LSMF/CH/AR has been revealed. A model has been suggested
to describe the interaction of the emerging toroids in the convection
zone and in the photosphere. The cellular convection, that develops at
the center of the toroids, is responsible for the occurrence of active
regions. The model qualitatively describes the observed particularities
of the LSMF/CH/AR system.

---------------------------------------------------------
Title: Dependence of the Density of the Upper Atmosphere on Solar
Activity from Satellite Drag Data
Authors: Shubin, V. N.; Deminov, M. G.; Nepomnyashchaya, E. V.;
Obridko, V. N.; Shelting, B. D.; Chizhenkov, V. A.
1997CosRe..35..114S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Large-scale structure of solar magnetic fields and coronal
mass ejections
Authors: Ivanov, E. V.; Obridko, V. N.; Shel'Ting, B. D.
1997ARep...41..236I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Relation between DIFOS "irradiance" data and solar activity.
Authors: Pflug, K.; Obridko, V. N.; Arlt, K.; Lebedev, N. I.
1997A&A...317..925P Altcode:
Solar irradiance measurements with the DIFOS-photometer aboard
the satellite CORONAS-I were compared with short term variations
of solar activity. The sunspot blocking effect was confirmed
and an anticorrelation with the 2600 MHz radio flux is very
pronounced. Furthermore a close relation to the large scale structure
of the magnetic field existed during the observational period from 1994,
March 16 to May 7.

---------------------------------------------------------
Title: Cyclic variation of the high-energy solar neutrino flux
Authors: Rivin, Yu. R.; Obridko, V. N.
1997ARep...41...76R Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Evolution of the Filament/CH/ Magnetic Field Complex
Authors: Ioshpa, B. A.; Mogilevskij, E. I.; Obridko, V. N.
1997jena.confE..41I Altcode:
The SOHO and Yohkoh images, as well as the H-alpha filtergrams and
magnetograms from IZMIRAN have been used to analyze the evolution of the
complex of related phenomena - filament, active region, and accompanying
pair of coronal holes - during two solar rotations in August-September,
1996. The whole complex has been considered against the large-scale
magnetic field, calculated under potential approximation. Peculiar
points have been isolated along the changing filament. It is shown
that the phenomena under investigation (filament, active region,
and coronal hole) form a single complex, connected with the magnetic
field structure.

---------------------------------------------------------
Title: The magnetic field in the near-equatorial zone of the solar
photosphere
Authors: Obridko, V. N.; Rivin, Yu. R.
1996ARep...40..740O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Forecasting the time series of Wolf numbers for the 23rd
solar cycle
Authors: Bondar', T. N.; Rotanova, N. M.; Obridko, V. N.
1996AstL...22..562B Altcode: 1996PAZh...22..628B
No abstract at ADS

---------------------------------------------------------
Title: The role of solar magnetic field in the neutrino flux
modulation.
Authors: Obridko, V. N.; Rivin, Y. R.
1996A&A...308..951O Altcode:
The flux of solar neutrino coming to the Earth is shown to be modulated
by the magnetic field on its propagation route. This explains the
11-year periodicity in the neutrino flux variation. Quasi-biennial
variations of the flux are claimed to have a different origin, i.e. to
be due to processes in the solar interior. Various indices used to
describe solar magnetic field variations are discussed, as well as
some implications of the obtained results.

---------------------------------------------------------
Title: Fourier Parameters and Moments of Polarization Profiles of
Magnetically Active Lines. Fourier Vector Magnetograph
Authors: Ioshpa, B.; Obridko, V.; Kozhevatov, I.
1996SoPh..164..373I Altcode:
A new method is proposed to determine all components of the solar
magnetic fields using the cumulants of the profile of a magnetic
sensitive line. The method is based on polarization measurements in
a number of points of the line profile and subsequent calculation of
the amplitudes and phases of its two first Fourier-harmonics.

---------------------------------------------------------
Title: Is Our Knowledge of Solar Indices Enough to Explain Satellite
Drag?
Authors: Deminov, M. G.; Nepomnyashchaya, E. V.; Obridko, V. N.;
Shelting, D. B.; Shubin, V. N.; Chizhenkov, V. A.
1996ASPC...95..421D Altcode: 1996sdit.conf..421D
No abstract at ADS

---------------------------------------------------------
Title: Calculating Solar Wind Parameters from Solar Magnetic
Field Data
Authors: Obridko, V. N.; Kharshiladze, A. F.; Shelting, D. B.
1996ASPC...95..366O Altcode: 1996sdit.conf..366O
No abstract at ADS

---------------------------------------------------------
Title: What Are the Solar Drivers Responsible for Helio-Meteorological
Effects?
Authors: Dmitrieva, I. V.; Obridko, V. N.; Zaborova, E. P.
1996ASPC...95..497D Altcode: 1996sdit.conf..497D
No abstract at ADS

---------------------------------------------------------
Title: On calculating the solar wind parameters from the solar
magnetic field data
Authors: Obridko, V. N.; Kharshiladze, A. F.; Shelting, B. D.
1996A&AT...11...65O Altcode:
It is shown that the expansion factor of the solar magnetic field
is insufficient to calculate the solar wind velocity. Moreover, the
magnetic field structure cannot unambiguously determine the solar
wind velocity field in therms of the source surface concept and the
potential magnetic field approximation in the corona. It is shown
that characteristics relating the solar and near-Earth interplanetary
magnetic field undergo cyclic variations.

---------------------------------------------------------
Title: Some aspects of heliometeorologic coupling
Authors: Obridko, V. N.; Oraevsky, V. N.; Dmitrieva, I. V.; Zaborova,
E. P.
1996A&AT....9..149O Altcode:
Solar activity events that influence the lower atmosphere of the
Earth have been considered as a function of various geographical
factors. Certain regions have been isolated, where meteorologic
characteristics are closely related to solar activity. The summer
duration in one of these regions is shown to correlate well with solar
activity characteristics, such as the Wolf number and the geomagnetic
aa-index. A hypothesis is suggested that there are certain zones through
which solar activity controls the entire Earth's atmosphere. The ways
to locate such zones are discussed.

---------------------------------------------------------
Title: Global magnetic studies of the sun - Properties of the polar
and equatorial fields
Authors: Ermakov, F. A.; Obridko, V. N.; Shel'Ting, B. D.
1995AZh....72..753E Altcode:
The odd-zone potential of the induction field B at the poles and
equator is considered. Extrema of the components Br and Bv fall in
phase minima and maxima, respectively, with the anomalous (non-dipole)
part substantially exceeding the normal (dipole) part. Behavior of the
empirical observational parameter q supports this fact for the poles.

---------------------------------------------------------
Title: Global magnetic studies of the Sun: Properties of the polar
and equatorial fields
Authors: Ermakov, F. A.; Obridko, V. N.; Shel'Ting, B. D.
1995ARep...39..672E Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The index of recurrence of planetary geomagnetic activity
and its connection with the solar cycle.
Authors: Levitin, A. E.; Obridko, V. N.; Val'Chuk, T. E.; Golyshev,
S. A.; Dremukhina, L. A.
1995Ge&Ae..35..137L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar Magnetic Field Modulation of the Neutrino Flux
Authors: Obridko, V. N.; Rivin, Yu. R.
1995IBVS.4160....1O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Some Comments on the Problem of Solar Cycle Prediction
Authors: Obridko, V. N.
1995SoPh..156..179O Altcode:
The paper provides a number of regression equations that can be
used to calculate the height of the odd Wolf number cycle. The
feasibility of the rule of Gnevyshev-Ohl is analyzed as applied to
the geomagneticaa-index. A modified rule of Gnevyshev-Ohl has been
formulated to describe the behaviour ofaa-indices. A new method is
suggested for early prediction of the next solar cycle. In this method,
the angular coefficient (straightline slope) of linear dependence
ofaa-indices on the Wolf number at the descending branch of the cycle
has been used as a prediction index. It is shown to a high degree of
certainty that the new prediction index is related to the height of
the forthcoming cycle. While the methods based on the ratio of the
even-odd cycles in a pair give very high values of cycle 23 maximum
(203.2 ± 10.7), our new index, on the contrary, gives very low values
(74.7 ± 6.9). There are some contradictory symptoms indicating that the
forthcoming cycle 23 is likely to violate the regularities established
for the past 125 years.

---------------------------------------------------------
Title: Stochastic autoregression modeling and forecasting of the
Wolf-number time series
Authors: Bondar', T. N.; Rotanova, N. M.; Obridko, V. N.
1995ARep...39..115B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the confidence level of the correlation between the
divergence factor of the lines of force on the sun and the solar-wind
velocity
Authors: Obridko, V. N.; Kharshiladze, A. F.; Shel'Ting, B. D.
1995ARep...39...95O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Global magnetology of the sun: Complementary fluxes and the
natural scale of cycles
Authors: Ermakov, F. A.; Obridko, V. N.; Shel'Ting, B. D.
1995ARep...39...86E Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Neutrino flux variations and solar magnetic fields.
Authors: Obridko, V. N.; Rivin, Yu. R.
1995BRASP..59.1562O Altcode:
It is shown that the neutrino flux emerging from the solar core is
modulated by a magnetic field, conditioning an 11-year cyclicity of the
flux. A quasi-two-year flux variation is related to another source,
i.e., the core processes. Various indices are considered to describe
heliomagnetic field variations as well as some consequences of this
consideration.

---------------------------------------------------------
Title: Cyclic variations of large-scale solar magnetic fields
Authors: Obridko, V. N.
1995BCrAO..92...67O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: International Decade of Solar Cycle Studies (IDSCS)
Authors: Obridko, V. N.; Oraevsky, V. N.; Allen, J. H.
1994step.conf..557O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Results of the Russian FLARES 22 Campaign
Authors: Obridko, V. N.; Ishkov, V. N.
1994step.conf...57O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: International studies of solar activity.
Authors: Obridko, V. N.; Oraevskij, V. N.
1993ZemVs...5...12O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Simulation of the Chain "Solar Activity-Weather-Ecology"
Authors: Obridko, V.; Dmitrieva, I.; Zaborova, E.
1993stp1.conf..243O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The Main Features of Solar Cycle 22 and Some Forecasts of
Cycle 23
Authors: Obridko, V.; Belov, A.; Ishkov, V.; Rivin, Y.; Kuklin, G.;
Vitinsky, Y.
1993stp2.conf..261O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar Cycle-Predictions Based on Solar Cycles Phases
Authors: Obridko, V.; Kuklin, G.
1993stp2.conf..273O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Frequency Composition of Multiyear Variations of the Magnetic
Field of the Sun as a Whole
Authors: Rivin, Y. R.; Obridko, V. N.
1992SvA....36..557R Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Frequency composition of long-period magnetic field variations
of the sun as a star
Authors: Rivin, Yu. R.; Obridko, V. N.
1992AZh....69.1083R Altcode:
The frequency composition of the general magnetic field of the sun as
a star is determined on the basis of Stanford observations, as well
as linear and square-law detection of the field during the period
June 1975-December 1990. Four groups of significant harmonics are
identified: long-period (greater than about 1 yr), and 27-, 13-, and 9-d
variations. A detailed analysis of the spectrum of diurnal values of
B(s), B(s)-parallel, and B(s)-squared, as well as of their semiannual
mean values and dispersions reveals a complex structure of long-period
B(s) variations (about 20-, 6-, 2-, and 1-yr variations). The agreement
of frequency characteristics of long-period B(s) variations with those
of the interplanetary magnetic field is discussed. The cause of the
11-yr cyclicity appearing in the detected B(s) values is analyzed.

---------------------------------------------------------
Title: Cyclic Variation of the Global Magnetic Field Indices
Authors: Obridko, V. N.; Shelting, B. D.
1992SoPh..137..167O Altcode:
The energetical aspect of solar phenomena of different spatial and
time scales has been studied with special attention to global magnetic
fields. Cyclic regularities in the heliosphere are determined by
energetics of global magnetic fields. The energy variation of global
fields consists of a number of maxima and minima coinciding with
reference points of the sunspot cycle. The correlations of a number of
well-known indices in the heliosphere with Wolf numbers and with indices
of energetics of the global magnetic field have been investigated. The
results can be used to identify more exactly the reference points of
the cycle.

---------------------------------------------------------
Title: Some Comments to the Problem of Extended Cycles in Large-Scale
Magnetic Fields
Authors: Obridko, Vladimir; Gaziev, Gulu
1992ASPC...27..410O Altcode: 1992socy.work..410O
No abstract at ADS

---------------------------------------------------------
Title: Coronal holes and photospheric magnetic fields
Authors: Obridko, V. N.; Shelting, B. D.
1990AZh....67..890O Altcode:
Magnetic field observations reported by Hoeksema and Scherrer (1986)
were used to examine the mutual arrangement of coronal holes recorded
in the 10830 He I line during the fall-off phase (1982-1985) of the
21st solar cycle, relative to the large-scale photospheric and coronal
magnetic fields. Results show that the coronal holes change in phase
with the total solar radiation flux in the Ca II line, indicating
their common nature. A mechanism for heating coronal holes, similar
to that proposed by Pikel'ner (1960), is discussed.

---------------------------------------------------------
Title: Some problems of investigation of the Sun within the STEP
program.
Authors: Kuklin, G. V.; Obridko, V. N.
1990Ge&Ae..30..529K Altcode:
The basic objectives of solar investigations in the framework of
the Solar-Terrestrial Energy Progam (STEP) are examined. Particular
attention is given to energy transfer from the inner layers outward
to the corona and heliosphere. Also considered are the generation of
magnetic fields and helioseismological methods for investigating the
inner structure of the sun. The interaction between local and global
fields is considered.

---------------------------------------------------------
Title: Coronal Holes and Photospheric Magnetic Fields
Authors: Obridko, V. N.; Shelting, B. D.
1990SvA....34..449O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Some problems of the investigation of the Sun within the
framework of the STEP project.
Authors: Kuklin, G. V.; Obridko, V. N.
1990Ge&Ae..30..449K Altcode:
The main problems of investigation of the Sun within the framework
of the international program Energy in the Sun-Earth System (STEP)
are formulated. The problems of energy transport from the inner layers
outwards right to the corona and heliosphere are discussed. The problems
of generation of magnetic fields and helioseismological methods
of studying the inner structure of the Sun are discussed. Special
attention is devoted to the interrelation of local and global fields.

---------------------------------------------------------
Title: Fine Structure of the Solar Cycle
Authors: Shelting, B. D.; Obridko, V. N.; Yermakov, F. A.
1989ATsir1540...23S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: SOLAR-CYCLE-21 in Heliomagnetic Indices
Authors: Obridko, V. N.; Yermakov, F. A.
1989ATsir1539...24O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Coronal holes as indicators of large-scale magnetic fields
in the corona
Authors: Obridko, V. N.; Shelting, B. D.
1989SoPh..124...73O Altcode:
It is shown that coronal holes may be used as indicators to trace the
location of the neutral line on the source surface in the corona. At
the same time, coronal holes are shown to concentrate in regions of
enhanced magnetic field at the source surface. This provides us with
a simple method for predicting the interplanetary current sheet and
sector structure which, in turn, determine the location of the proton
complexes and the outflow regions of high-velocity streams. Rotation of
coronal holes has been studied. Rather than being rigid, it displays
the same reduced differentiallity as the rest of the corona. However,
there are particular periods 2 or 3 years before the cycle minimum
when the solid-body type of rotation is settled for both the coronal
holes and the corona as a whole.

---------------------------------------------------------
Title: The Spacetime Polarity Distribution of the Largescale Solar
Magnetic Field
Authors: Obridko, V. N.; Makarov, V. I.; Tavastsherna, K. S.; Gaziev,
G. A.
1989ATsir1536...31O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The Sun as a Source of Energy and Mass
Authors: Kuklin, G. V.; Obridko, V. N.
1989step.conf....7K Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar/terrestrial physics
Authors: Ivanov-Kholodnyi, G. S.; Lotova, N. A.; Obridko, V. N.;
Fel'Dshtein, Ia. I.; Fomichev, V. V.
1989epps.book...36I Altcode:
The history of the development of solar/terrestrial physics research at
IZMIRAN (the Soviet Institute for the Study of Terrestrial Magnetism,
the Ionosphere, and the Propagation of Radio Waves) is reviewed, and the
activity of the Institute in organizing international solar/terrestrial
physics research is examined. Particular attention is given to
investigations of solar corpuscular radiation and its effect on the
ionosphere; and to studies of auroras and the interplanetary medium.

---------------------------------------------------------
Title: Dispersion of monthly mean Wolf's numbers as a prediction
index.
Authors: Obridko, V. N.
1989BSolD..11..106O Altcode:
It is shown that at the decreasing branch of the cycle the
r.m.s. deviation of monthly mean Wolf's numbers from their smoothed
values correlates with the height of the next maximum (the correlation
coefficient is 0.649). This gives predicted W22 = 138±20.9.

---------------------------------------------------------
Title: Book Review: The solar wind and the earth. / Reidel, 1987
Authors: Obridko, V.; Obridko, V.
1988SoPh..116..409O Altcode: 1988SoPh..116..409A
No abstract at ADS

---------------------------------------------------------
Title: Coronal holes and prediction of recurrent high-velocity
streams.
Authors: Shel'Ting, B. D.; Obridko, V. N.
1988KFNT....4...29S Altcode:
Data for 1973 - 1979 have been used to study the relationships between
the large-scale solar magnetic field, coronal holes, the IMF sector
structure and high-velocity streams by applying the cross-correlation
analysis and direct comparison. Remarkably high time and space
correlations have been obtained.

---------------------------------------------------------
Title: Book-Review - Solar Maximum Analysis - Proceedings
International Workshop - Irkutsk U.S.S.R. - 1985JUN17-24
Authors: Stepanov, V. E.; Obridko, V. N.
1988S&T....75R.498S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: A two-component working model for the atmosphere of a large
sunspot umbra
Authors: Obridko, V. N.; Staude, J.
1988A&A...189..232O Altcode:
A two-component working model for the atmosphere of the umbra of a
typical large sunspot is proposed which represents an improvement
over the earlier Wroclaw-Ondrejov sunspot model. The main component
is assumed to consist of cold matter at photospheric levels, a thin
chromosphere, a shallow transition region, and a deep-set corona. The
secondary component in the model has a volume filling factor of
5-10 percent at all heights and is suggested to consist of thin
fine-structure elements which are elongated parallel to the magnetic
field. The present model is able to account for the basic features of
sunspot observations at frequencies from X-rays up to microwaves.

---------------------------------------------------------
Title: Differential rotation of the sun
Authors: Obridko, V. N.; Shel'Ting, B. D.
1988IGAFS..83....3O Altcode:
Recent results on the differential rotation of the sun are reviewed. It
is shown that the concept of the differential rotation of tracers
is supported by a large body of observational evidence; most of the
tracers display maximum equatorial velocity at the end of a cycle and
an abrupt decrease of differentiality several years prior to that. A
number of sharp narrow peaks have been revealed in the frequency
spectrum, suggesting the existence of separate (perhaps rigid-body)
modes with synodic periods of 27.2 and 28.4 days.

---------------------------------------------------------
Title: On the differential rotation of coronal holes.
Authors: Obridko, V. N.; Shel'Ting, B. D.
1988BSolD1988...89O Altcode:
It is shown that the differential character of rotation of coronal
holes is weakly pronounced (B ≡ 0.4) only near the solar minimum,
i.e., in the period when the green corona also rotates rigidly. In
other periods, coronal holes as well as the entire corona display a
noticeable differential rotation (B ⪆ 1.0).

---------------------------------------------------------
Title: Rotation of the sector structure of the interplanetary magnetic
field(1926 - 1980).
Authors: Kuklin, G. V.; Obridko, V. N.
1988BSolD1988...78K Altcode:
Dynamics of the rotation of the interplanetary magnetic field sector
structure is analysed for 1926 - 1980. Discrete rotation periods,
coexistence of not more than two rotation systems, presence of
acceleration and deceleration of rotation, influence of the places
and parity of the 11 year solar cycle and phases of the secular cycle
are detected. Some peculiarities of rotation are suspected to be due
to the presence of zonal winds in the solar corona, influencing the
outflowing magnetic field.

---------------------------------------------------------
Title: Prognozirovanie ionosfernykh, magnitosfernykh vozmushchenij
i solnechnoj aktivnosti (Prediction of ionospheric, magnetospheric
disturbances and of solar activity).
Authors: Zevakina, R. A.; Obridko, V. N.
1988pimv.book.....Z Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Reciprocal space-time localization of the sector structure
of the interplanetary magnetic field and the large-scale field of
the Sun.
Authors: Obridko, V. N.; Shel'Ting, B. D.
1987Ge&Ae..27..660O Altcode:
The statistical correlation between the large-scale solar magnetic
field and the IMF sector structure is examined. It is shown that,
despite a close interrelationship, there can be slight divergences
between the two, connected with the inadequacy of their determination
and the presence of short-term perturbations. A refined determination
is made of the boundary-zone width between the beginning of the coronal
hole and the boundary of the large-scale solar magnetic field; a value
of 40-50 heliographic degrees is obtained.

---------------------------------------------------------
Title: Energetics of activity of flare stars and the Sun: a
synergetical approach.
Authors: Gershberg, R. E.; Mogilevskii, E. I.; Obridko, V. N.
1987KFNT....3R...3G Altcode: 1987KNFT....3R...3G; 1987KFNT....3e...3G
The analysis of the energy spectra of flares on flare stars and on
the Sun shows that the maximum energy of optical radiation of stellar
flares is close to 1029J and of solar flares is several
units of 1025J; taken into account the electromagnetic
emission in other wavelength ranges, losses on particle acceleration
and hydrodynamic losses, it is concluded that the total energy
released in such flares must exceed the above estimates by an order
of magnitude. Difficulties of the standard model of current sheets in
providing a high energy release in powerful solar and stellar flares
are discussed and the necessity of a synergetical approach to analyse
structural and kinematic properties of convective zones in the stars
with a magnetic field is substantiated. The model of soliton gas as a
mechanism of rapid transport of large portions of magnetic energy from
deep convection layers into the atmosphere is suggested and discussed
in brief. This mechanism seems to be able to provide the energetics
of the most powerful solar and stellar flares.

---------------------------------------------------------
Title: Relationship between coronal holes, high-velocity streams
and the sector structure of the interplanetary magnetic field.
Authors: Obridko, V. N.; Shel'Ting, B. D.
1987Ge&Ae..27..197O Altcode:
A statistical analysis of a large volume of data shows that most
high-speed streams of the solar wind are generated right after passage
through the sector structure (SS) of the IMF and just before passage
through the coronal-hole (CH) boundary. About 74 to 87 percent of the
CH is located within sectors of the same polarity, and the width of
the boundary zone between the SS and CH commencement amounts to 20-40
heliographic degrees. About 38-57 percent of all high-speed streams
connected with CHs commence in this zone.

---------------------------------------------------------
Title: Solar Maximum Analysis. Proceedings of the International
Workshop, held in Irkutsk, USSR, June 17-24, 1985.
Authors: Stepanov, V. E.; Obridko, V. N.
1987sman.work.....S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Prediction of ionospheric and magnetospheric disturbances
and solar activity
Authors: Zevakina, R. A.; Obridko, V. N.
1987pimd.conf.....Z Altcode:
Papers are presented on such topics as the short-term forecasting
of solar activity, the use of radio emission for the diagnostics of
proton flares and geoefficient phenomena on the sun, the geomagnetic
diagnostics of the parameters of the solar wind and the magnetosphere,
and the prediction of ionospheric disturbances. Attention is also given
to the forecasting of F2-layer electron density during disturbances,
mathematical methods for the short-term forecasting of F2-layer critical
frequencies, and the use of numerical models of the ionosphere for
ionospheric forecasting.

---------------------------------------------------------
Title: Solar-terrestrial physics: problems and perspectives.
Authors: Migulin, V. V.; Miroshnichenko, L. I.; Obridko, V. N.
1987VeSSR...9...83M Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Book-Review - Sunspots and Activity Complexes
Authors: Obridko, V. N.; Hejna, L.
1986BAICz..37..316O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Cyclic variations of a connection between the interplanetary
magneticfield sector structure, high-velocity streams and geomagnetic
disturbances.
Authors: Obridko, V. N.; Konstantinova, L. Iu.; Konakh, M. M.;
Mansurov, G. S.
1986Ge&Ae..26..313O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Cyclic Variations of the Solar Radio Flux at 10.7-CM and
3.2-CM and Their Prognostic Implications
Authors: Danilchev, B. V.; Morozova, L. P.; Obridko, V. N.
1986BSolD...4...69D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Cyclic variations of the solar radio flux at 10.7 and 3.2 cm
and their prognostic implications.
Authors: Danil'Chev, B. V.; Morozova, L. P.; Obridko, V. N.
1986BSolD1986...69D Altcode:
Cyclic variations of the solar radio flux at 3 and 10 cm wavelengths
have been investigated. A phenomenon of pre-minimum has been discovered
to take place in 1971, when a number of indices indicated the sun-earth
conditions similar to those that are usually registered at the minimum
of Wolf numbers. Prognostic implications of the deviation from a
regression dependence between the 3 and 10 cm fluxes are discussed.

---------------------------------------------------------
Title: On principal phases of the solar cycle.
Authors: Vitinskij, Yu. I.; Kuklin, G. V.; Obridko, V. N.
1986BSolD1986...53V Altcode:
The necessity of revision in traditional concepts of the solar cycle
is argued. A new description of principal phases of the solar cycle
using a set of different observational data is given. An approach to
a further detailed analysis of this problem is determined.

---------------------------------------------------------
Title: Fluctuation characteristics of the interplanetary magnetic
field in the frequency range 3×10-4 - 10-2Hz.
Authors: Obridko, V. N.; Shelting, B. D.
1985Ge&Ae..25..881O Altcode:
The fluctuation characteristics of the IMF for a series of proton events
were studied on the basis of measurements of IMF components carried
out on the Explorer 33 and 34 satellites with a time resolution of 5
sec and a measurement accuracy of 0.1 nT. The fluctuations are shown
to be mainly determined by Alfven waves; the contribution of other
types of waves increases during disturbed periods. The fluctuation
spectrum in the whole frequency range studied cannot be described by a
power law with the same exponent alpha. The value of alpha is 1.2-1.5
at the low-frequency end of the spectrum, and falls to 0.5-0.8 at the
high-frequency end.

---------------------------------------------------------
Title: Solnechnye piatna i kompleksy aktivnosti
Authors: Obridko, V. N.
1985spka.book.....O Altcode: 1985QB525.O27......
No abstract at ADS

---------------------------------------------------------
Title: Sunspots and activity complexes.
Authors: Obridko, V. N.
1985sac..book.....O Altcode:
The physics of sunspots is treated, with attention given to
observational aspects and to the related theory. The structure and
models of sunspot umbras and penumbras are examined from a unified
point of view as well as the magnetic-field structure, wave processes,
energy transfer, and the corona and chromosphere of sunspots. Analogous
phenomena occurring in stars are also analyzed. It is noted that a
global-type of organization is another characteristic of solar plasma.

---------------------------------------------------------
Title: The evolution of the IMF sector structure for the period of
1926 - 1980.
Authors: Obridko, V. N.
1985BSolD1984...54O Altcode:
The evolution of the IMF sector structure has been studied using an
objective method with application of autocorrelation functions. It is
shown that the main state of the IMF is the two-sector structure. The
four-sector structure appears at the descending branch of the solar
cycle and has a short life time.

---------------------------------------------------------
Title: The Behaviour of the Interplanetary Magnetic Field Fluctuations
in the Frequency Interval of 10/-3-HZ to 10/-5-HZ
Authors: Obridko, V. N.; Shelting, B. D.
1985BSolD...9...91O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On Principal Phases of the Solar Cycle
Authors: Vitinsky, Y. I.; Kuklin, G. V.; Obridko, V. N.
1985BSolD...3...53V Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The behaviour of the interplanetary magnetic field fluctuations
in the frequency interval of 10-3 - 10-5Hz.
Authors: Obridko, V. N.; Shel'Ting, B. D.
1985BSolD1985...91O Altcode:
The fluctuations of the interplanetary magnetic field in the frequency
interval of 10-3 - 10-5Hz for the quiet period
(14 - 20 July 1965) and the weak activity period (5 - 7 June 1965)
are investigated. Periods of 20 - 22h, 4 - 8h
and 2 - 3h are detected. The interpretation of these periods
is given.

---------------------------------------------------------
Title: The Atmosphere of a Sunspot Based on Observations in the
X-Ray Extreme Ultraviolet Optical and Radio Ranges
Authors: Staude, J.; Furstenberg, F.; Hildebrandt, J.; Kruger,
A.; Jakimiec, J.; Obridko, V. N.; Siarkowski, M.; Sylwester, B.;
Sylwester, J.
1984SvA....28..557S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Comparative Characteristics of Stellar and Sunspot Spectra
Authors: Badalyan, O. G.; Obridko, V. N.
1984SvA....28..564B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The atmosphere of a sunspot based on observations in the X-ray,
extreme ultraviolet, optical, and radio ranges
Authors: Staude, J.; Furstenberg, F.; Hildebrandt, J.; Kruger,
A.; Jakimiec, J.; Obridko, V. N.; Siarkowski, M.; Sylwester, B.;
Sylwester, J.
1984AZh....61..956S Altcode:
A model of the solar atmosphere above a sunspot umbra is developed on
the basis of published X-ray, EUV, optical, and radio observations,
summarizing the findings of working conferences held at Wroclaw in
November-December 1979 (Bromboszcz et al. 1981) and at Ondrejov in
September-October 1981 (Bromboszcz et al., 1982). A lower-chromosphere
model like that of Teplitskaya et al. (1977 and 1978) is extended
upward by applying a strong temperature gradient, with T = 40,000 K
and n(e) = 4 x 10 to the 10th/cu cm at z = 2000 km above the umbral
chromosphere. At z = 3000-5000 km, cool loops with T = (1-100) x 10
to the 4th k are surrounded by hot (1.8 x 10 to the 6th K) coronal
matter with a narrow transition layer and n(e) = 5 x 10 to the 8th/cu
cm which occupies 0.8-0.9 of the total volume.

---------------------------------------------------------
Title: Comparative spectral characteristics of stars and sunspot
spectra.
Authors: Badalyan, O. G.; Obridko, V. N.
1984AZh....61..968B Altcode:
A comparative analysis of the spectra of dwarf stars and a sunspot is
made. It is shown that the spectral class of a sunspot depends on the
index used: A sunspot has the class M0 based on the continuous spectrum,
about K5 based on weak lines, and G8-K0 based on strong lines. From this
it follows that the atmosphere of a sunspot cannot be likened to the
average standard atmosphere of a star of any spectral class. This may be
connected with the specific role of magnetic fields, the inhomogeneous
structure of the atmospehre, horizontal energy transfer in a sunspot,
and the force of gravity, which is different from that of a star with
the same effective temperature.

---------------------------------------------------------
Title: Fluctuations of the interplanetary and geomagnetic fields in
connection with proton bursts.
Authors: Shelting, B. D.; Valchuk, T. E.; Feldshtein, Ia. I.; Obridko,
V. N.
1984Ge&Ae..24..557S Altcode:
A spectral analysis is made of oscillations in the interplanetary
magnetic field (IMF) and geomagnetic field (GF) before, during,
and after the solar flares of April 3, June 9, and October 30,
1968. Fluctuations with periods of several minutes to tens of minutes
are shown to exist in the IMF and GF.

---------------------------------------------------------
Title: The Evolution of the IMF Sector for the Period of 1926-1980
Authors: Obridko, V. N.
1984BSolD..11...54O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: A working model of sunspot structure in photosphere,
chromosphere and corona, derived from X-ray, EUV, optical and radio
observations
Authors: Staude, J.; Hildebrandt, J.; Fuerstenberg, F.; Krueger,
A.; Jakimiec, J.; Obridko, V. N.; Siarkowski, M.; Sylwester, B.;
Sylwester, J.
1983AcA....33..441S Altcode:
The presented sunspot model consists of several parts which have been
consistently put together: the umbral model describing the spatial
distribution of thermodynamic quantities up to the transition region as
derived from EUV and optical observations, the magnetic field model,
the model of X-ray emission, and the S-component emission model. The
model assumptions have been tested and corroborated by recently
published observations with high spatial resolution obtained in the
X-ray and EUV spectral range from Skylab, HRTS, and SMM, at centimeter
wavelengths from RATAN, VLA, and WSRT, and by ground-based magnetograms.

---------------------------------------------------------
Title: Some trends in modern solar physics.
Authors: Obridko, V. N.
1983PDHO....5...25O Altcode: 1984PDHO....5...25O
Discussed are the main three trends in modern solar physics i.e.,
the study of solar plasmas as a set of discrete structural elements
in time and space, the study of global organization of solar activity,
and the closer relationships between solar and stellar investigations.

---------------------------------------------------------
Title: Solar Image Properties at a Site Near Norilsk
Authors: Bojarskij, D. A.; Kononovich, E. V.; Kupriakov, Y. A.;
Kononov, E. Y.; Smirnova, O. B.; Obridko, V. N.
1983ATsir1289....1B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Characteristics of IMF Fluctuation Spectrum and the Level of
Solar Activity
Authors: Obridko, V. N.; Shelting, B. D.
1983BSolD...9...80O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar image properties at a site near Norilsk.
Authors: Boyarskij, Ya.; Kononovich, Eh. V.; Kupryakov, Yu. A.;
Kononov, Eh. Ya.; Smirnova, O. B.; Obridko, V. N.
1983ATsir1289....3B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Characteristics of the spectrum of fluctuations of the
interplanetarymagnetic field and the level of solar activity.
Authors: Obridko, V. N.; Shel'Ting, B. D.
1983BSolD1983...80O Altcode:
The IMF fluctuation spectrum has been analyzed for different solar
activity conditions. It has been shown that the fluctuation power in the
frequency range of 10-3 - 10-4 Hz increases before
flares with a simultaneous decrease of the energy spectrum inclination.

---------------------------------------------------------
Title: Analysis of cyclic variations of the sector structure of the
interplanetary magnetic field during the period from 1926 to 1980.
Authors: Obridko, V. N.
1981pkem.conf...21O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Structure of the atmosphere above sunspots
Authors: Obridko, V. N.
1979SvA....23...38O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Structure of the atmosphere above sunspots
Authors: Obridko, V. N.
1979AZh....56...67O Altcode:
A comparison of optical, radio, UV, and X-ray observations reveals
the necessity of an improved model for the atmosphere above sunspot. A
two-component model is suggested consisting of a double loop system. The
loops connected with local fields in the vicinity of a sunspot have a
temperature up to 700,000 K, and those connected with large-scale fields
far away in the active region or with the fields of other active regions
have a temperature of at least 2 million K. The relative volume occupied
by the loops of both types varies with height. The model accounts for
the main characteristics of all the kinds of emission considered.

---------------------------------------------------------
Title: Isolating protective shell around a sunspot umbra.
Authors: Obridko, V. N.
1979BSolD1979...96O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The Origin of Bright Umbral Elements and Forced Oscillatory
Convection
Authors: Obridko, V. N.
1979BSolD...3..101O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Temperature distribution in an inhomogeneous medium with
radiative equilibrium.
Authors: Obridko, V. N.; Dashevskij, V. M.; Badalyan, O. G.
1979fsif.conf...16O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Insulating Protective Shell around the Sunspot Umbra
Authors: Obridko, V. N.
1979BSolD...4...96O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Fizika Solntsa
Authors: Obridko, V. N.; Teplitskaia, R. B.; Dubov, E. E.
1978fiso.book.....O Altcode: 1978QB3.I88t14.....
No abstract at ADS

---------------------------------------------------------
Title: Physical conditions in sunspots.
Authors: Obridko, V. N.; Teplitskaya, R. B.
1978pos..conf....7O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Physical conditions in a sunspot penumbra.
Authors: Obridko, V. N.; Badalyan, O. G.
1977BSolD1977...98O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Index of compactness of solar active regions and
characteristics of proton events.
Authors: Kasinskij, V. V.; Ivanov, E. V.; Obridko, V. N.
1977IGAFS..42...34K Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Physical conditions in sunspots.
Authors: Obridko, V. N.; Teplitskaya, R. B.
1976fsp..conf....3O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Anomalies in the Zeeman triplet in a sunspot spectrum.
Authors: Demkina, L. B.; Obridko, V. N.
1976fsp..conf...58D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Temperature distribution in a non-homogeneous medium with
radiative equilibrium.
Authors: Obridko, V. N.; Dashevskij, V. M.; Badalyan, O. G.
1976fsp..conf...54O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Variations in the intensity of photospheric lines and the
continuum due to small changes of the physical parameters
Authors: Badalian, O. G.; Obridko, V. N.
1976SvA....19..342B Altcode: 1975SvA....19..342B
Formulas are derived which associate intensity variations of
the solar Fraunhofer lines and continuum with small changes in
model parameters. It is shown that application of these formulas to
observations of facula spectra confirms the presence of a superheated
region in faculae.

---------------------------------------------------------
Title: Origin of bright umbral dots in sunspots
Authors: Obridko, V. N.
1975SvA....18..758O Altcode:
'Bright umbral dots' are investigated on the basis of a model in
which they are considered the result of an instability in deep sunspot
layers. A mathematical model of convective instability in the presence
of a magnetic field is analyzed to obtain an overall picture of the
excitation, development, and decomposition of the structures. These
stages are delineated: raising of matter into a low-magnetic cavity
resulting from the formation of a convective cell in deep layers
of a sunspot; convective transfer of energy into the cavity, which
sustains the brightness of the structure; decreases in the temperature
gradient of the cavity and in the convective energy and strengthening
of the magnetic field, which cuts off the influx of energy from below;
gradual deexcitation and decomposition of the bright structures. The
lifetime of the structures is briefly noted along with the possible
use of this mechanism to determine the fine structure of the magnetic
field of a sunspot.

---------------------------------------------------------
Title: Variations in the intensity of photospheric lines and the
continuum due to small changes of the physical parameters
Authors: Badalian, O. G.; Obridko, V. N.
1975AZh....52..561B Altcode:
Formulas are derived which associate intensity variations of
the solar Fraunhofer lines and continuum with small changes in
model parameters. It is shown that application of these formulas to
observations of facula spectra confirms the presence of a superheated
region in faculae.

---------------------------------------------------------
Title: Catalog of solar particles events, 1955 - 1969.
Authors: Dodson, H. W.; Hedeman, E. R.; Kreplin, R. W.; Martres,
M. -J.; Obridko, V. N.; Shea, M. A.; Smart, D.; Tanaka, H.; Svestka,
Z.; Simon, P.; Fritzová-Svestková, L.; Guitart, A.
1975cspe.book.....D Altcode: 1975QB505.C37......
No abstract at ADS

---------------------------------------------------------
Title: Origin of bright umbral dots in sunspots
Authors: Obridko, V. N.
1974AZh....51.1272O Altcode:
'Bright umbral dots' are investigated on the basis of a model in
which they are considered the result of an instability in deep sunspot
layers. A mathematical model of convective instability in the presence
of a magnetic field is analyzed to obtain an overall picture of the
excitation, development, and decomposition of the structures. These
stages are delineated: raising of matter into a low-magnetic cavity
resulting from the formation of a convective cell in deep layers
of a sunspot; convective transfer of energy into the cavity, which
sustains the brightness of the structure; decreases in the temperature
gradient of the cavity and in the convective energy and strengthening
of the magnetic field, which cuts off the influx of energy from below;
gradual deexcitation and decomposition of the bright structures. The
lifetime of the structures is briefly noted along with the possible
use of this mechanism to determine the fine structure of the magnetic
field of a sunspot.

---------------------------------------------------------
Title: Solar Proton Flares and the Sector Structure of the
Interplanetary Magnetic Field
Authors: Obridko, V. N.; Mansurov, S. M.; Mansurova, L. G.
1974Ge&Ae..14....1O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar proton flares and the sectorial structure of the
interplanetary magnetic field.
Authors: Obridko, V. N.; Mansurov, S. M.; Mansurova, L. G.
1974GeA....14....3O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: An inhomogeneous sunspot model. II. Spectral line
intensification in a spot.
Authors: Obridko, V. N.
1974BSolD1974...72O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: An inhomogeneous sunspot model. I. The effect of inhomogeneity
on the evaluation of "empirical" models.
Authors: Obridko, V. N.
1974BSolD1974...73O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the Polarization of the Solar Coronal Emission Lines
Authors: Mogilevsky, E.; Ioshpa, B.; Obridko, V.
1973SoPh...33..169M Altcode:
The results of the spectrophotometrical measurements of the
polarization in the coronal lines Fe xiv 5303 Å and Fe × 6374 Å are
given. Polarization spectrograms were obtained by two spectrographs
(prism and echelle types) during the solar eclipse in Mexico on 7 March,
1970 near the region of the second contact at the heights 0.06 to 0.12
R⊙ above the limb. The polarization in the green line is
about 30% (for averaged height 1.08 R⊙). The polarization
in the red line is close to the errors of the measurement and does
not exceed 6%. A brief discussion of the results is also given.

---------------------------------------------------------
Title: The Spectrum of Low-Frequency Oscillations of the Magnetic
Field of Sunspots, and Low-Frequency Modulation of the Radioemission
from the Active Regions of the Sun
Authors: Mogilevskii, É. I.; Obridko, V. N.; Shel'Ting, B. D.
1973R&QE...16.1043M Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Polarization of the Radiation of Magnetic Stars.
Authors: Demkina, L. B.; Obridko, V. N.
1973SvA....16..853D Altcode: 1973SvA....16..852D
No abstract at ADS

---------------------------------------------------------
Title: Short-Periodic Oscillations of the Magnetic Field of the Sun
as a Star
Authors: Ioshpa, B. A.; Obridko, V. N.; Shelting, B. D.
1973SoPh...29..385I Altcode:
lCorrelation analysis applied to recordings of the magnetic field and
velocity of the Sun as a star reveals oscillations close to 300 s. The
power spectrum of these oscillations is discussed.

---------------------------------------------------------
Title: Temperature Distribution in an Irregularity in Radiative
Equilibrium.
Authors: Dashevskii, V. M.; Obridko, V. N.
1973SvA....16..651D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The spectrum of low-frequency oscillations of the magnetic
field of sunspots and low-frequency modulation of radio emission of
solar active regions.
Authors: Mogilevskij, Eh. I.; Obridko, V. N.; Shel'Ting, B. D.
1973IzVUZ..16.1357M Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Polarization of the Radiation of Magnetic Stars.
Authors: Demkina, L. B.; Obridko, V. N.
1972AZh....49.1046D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the Interpretation of the π-Component Splitting in
Sunspot Spectra
Authors: Obridko, V. N.; Demkina, L. B.
1972SoPh...24..336O Altcode:
It is shown that in order to explain the observed splitting of the
π-component in the sunspot umbra spectrum by the hypothesis of
the coexistence in sunspots of weak- and strong-field regions with
opposite polarities, one has to admit the additional assumption that
in the weak-field regions the Doppler halfwidth (ΔλD) and
the ratio between line opacity and continuum opacity (η0)
are both less than those in the strong-field regions.

---------------------------------------------------------
Title: On the wings of the sigma -components of magnetically sensitive
lines in sunspots.
Authors: Demkina, L. B.; Obridko, V. N.
1972BSolD1972..101D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Large-Scale Mutual Relations of Spot Groups in Proton Complex
Authors: Křivský, L.; Obridko, V.
1969SoPh....6..418K Altcode:
The large-scale configuration of spot groups was investigated within a
complex proton region. The probability of occurrence of accompanying
spot groups (satellites) was studied according to the classification
types, the direction of their occurrence, and the distance with
respect to the proton spot group. The results obtained indicate that
the condition for the generation of a proton spot group will not only
rest with the known small-scale interaction of a few magnetic systems
and the creation of a single group, but also with the existence of
`satellites' in the neighbourhood of the proton group up to a distance
of several tens of degrees.

---------------------------------------------------------
Title: Problems of solar-terrestrial physics (Symposium at Crimea).
Authors: Zhulin, I. A.; Obridko, V. N.
1969VeSSR...4...95Z Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Magnetic field decay in the group 21034 during the proton
flare period of July 1966.
Authors: Mogilevsky, E. I.; Demkina, L. B.; Dolginova, Yu. N.; Ioshpa,
B. A.; Obridko, V. N.; Shelting, B. D.; Zhulin, I. A.
1969AIQSY...3..222M Altcode:
No abstract at ADS

---------------------------------------------------------
Title: `Bartels' active longitudes', sector boundaries and flare
activity
Authors: Bumba, V.; Obridko, V. N.
1969SoPh....6..104B Altcode:
The flare activity and especially the proton-flare activity is
concentrated in the zones of `Bartels' active longitudes' and in the
neighbourhood closest to the sector boundaries of the interplanetary
magnetic field. This concentration seems to be greater if the importance
of the event increases.

---------------------------------------------------------
Title: Some comments on the long-term forecasts of proton flares
Authors: Obridko, V. N.
1969BAICz..20...37O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the Energy Release by Magnetic Field Dissipation in the
Solar Atmosphere
Authors: Kopecký, M.; Obridko, V.
1968SoPh....5..354K Altcode:
The energy release by Joule magnetic-field dissipation in the solar
atmosphere is discussed. It is shown that the heating is unimportant
in the case of granulation and intergranular space. In the case of spot
features the additional temperatures ΔTr with the accounting
of the radiation losses are no more than 30° for small new spots,
≈ 1° for the large umbrae and 300° for bright points in large
umbrae. This effect gives the possibility to suggest a hypothesis on
the source of temperature inhomogeneity in the spot umbra and the nature
of bright points. In the chromosphere the dissipation is negligible.

---------------------------------------------------------
Title: On the Structure of the Magnetic Field of Sunspots
Authors: Mogilevsky, E. I.; Demkina, L. B.; Ioshpa, B. A.; Obridko,
V. N.
1968IAUS...35..215M Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the two-component structure of the sunspot magnetic field
Authors: Obridko, V. N.
1968BAICz..19..183O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Applicability of the Existing Theories of the Formation of
Spectral Lines in a Magnetic Field for Quantitative Interpretation
of Solar Magnetograph Readings
Authors: Obridko, V. N.
1968soac.conf...86O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the two-component sunspot model
Authors: Obridko, V. N.
1968BAICz..19..186O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Simultaneous Measurement of Magnetic Fields on Two Levels in
the Sun's Atmosphere
Authors: Zhulin, I. A.; Ioshpa, B. A.; Mogilevsky, E. I.; Obridko,
V. N.
1968soac.conf...39Z Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Magnetic-Field Radiation-Scattering Matrix Derived With
Allowance for the Phase Couplings of the Upper-Level Wave Function
Authors: Obridko, V. N.
1968soac.conf...77O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Radio Emission and Atmospheric Structure above Sunspots
Authors: Livshits, M. A.; Obridko, V. N.; Pikel'Ner, S. B.
1967SvA....10..909L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Development of a Solar Absorption Line with a Split Upper
Level in a Magnetic Field
Authors: Obridko, V. N.
1965SvA.....9..398O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Scattering Matrix for Radiation in a Magnetic Field
Authors: Obridko, V. N.
1965SvA.....9...77O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Computation of the Components of the Total Vector from
Observations with a Solar Magnetograph
Authors: Karnitskaya, Ye. A.; Obridko, V. N.
1965Ge&Ae...5..257K Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Scattering Matrix for Radiation in a Magnetic Field
Authors: Obridko, V. N.
1965AZh....42..102O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Measurement of the Magnitude and Direction of the Magnetic
Field in the Region of Sunspots
Authors: Ioshpa, B. A.; Obridko, V. N.
1964SvA.....7..776I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Measurement of the Magnitude of the Magnetic Field on the Sun
Authors: Ioshpa, B. A.; Obridko, V. N.
1964Ge&Ae...4...12I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The K232 Line Profile and the Structure of the
Solar Atmosphere
Authors: Obridko, V. N.
1963SvA.....7..342O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Problem of Measuring the Absolute Magnitude of the Magnetic
Field on the Sun with a Photoelectric Magnetometer
Authors: Ioshpa, B. A.; Obridko, V. N.
1962Ge&Ae...2..451I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Low-Noise Receiver for an Ionospheric Station
Authors: Iospha, B. A.; Obridko, V. N.
1962Ge&Ae...2..454I Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Excitation of the Ca II K Line in the Solar Chromosphere
Authors: Obridko, V. N.
1961SvA.....4..961O Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Excitation of the Ca II K Line in the Solar Chromosphere
Authors: Obridko, V. N.
1960AZh....37.1028O Altcode:
No abstract at ADS