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Author name code: november
ADS astronomy entries on 2022-09-14
author:"November, Laurence J."
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Title: The Astrophysical Corona as the Minimum Atmosphere Surrounding
Embedded Non-Force-Free Flux Tubes
Authors: November, Laurence J.
2019arXiv190309993N Altcode:
The equilibrium of current-carrying magnetic fields (e.g. flux tubes)
embedded in a large-scale background field is developed and discussed
in the astrophysical context. Embedded non-force-free current-carrying
fields require a minimum surrounding atmosphere, which by direct
pressure balance has a gas pressure everywhere proportional to the
background magnetic pressure. Formally, the MHD equations, with flows
and gravity as part of a wide class of physical processes, separate
into independent local and global relations representing an equilibrium
solution for embedded current-carrying fields. The local pressure
relation for the embedded field is a 3D Grad-Shafranov equation with
finite-sheath solutions. The global relation reproduces the ambient
MHD pressure equation without the embedded fields, but instead with
the constraint that the ambient gas and magnetic pressures vary in
proportion, as with the direct pressure balance. A coupled gas pressure
in magnetically dominant regimes necessitates refilling outflows in a
depleted atmosphere (actualized by flux-tube Lorentz forces) providing
a compressively heated equilibrium corona with a specific global
distribution of density, temperature, and steady accelerated outflow,
all defined by the large-scale background magnetic field. Magnetic
footpoint compression and twisting in a high-gas-pressure field-forming
region (e.g. convection zone) outside, as below, the magnetically
dominant regime, can introduce and sustain non-force-free embedded
fields, thereby providing the energy for the coronal atmosphere. Such
coronae may be relevant on very different astrophysical scales:
around the sun and stars, and ranging from planets, to neutron stars,
black holes, and spiral galaxies. Predicted coronal temperatures are
corroborated.
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Title: Magnetohydrostatic (MHS) atmospheres
Authors: November, L. J.
2004A&A...417..333N Altcode: 2003astro.ph..4486N
We show that the atmospheric and magnetic height variations are
coupled in general MHS equilibria with gravity when isolated thin
non-force-free flux tubes are present. In gas-dominated environments,
as in stellar photospheres, flux tubes must expand rapidly with
height to maintain pressure balance with the cool surroundings. But
in magnetically dominated environments, as in stellar coronae,
the large-scale background magnetic field determines the average
spreading of embedded flux tubes, and rigidly held flux tubes require a
specific surrounding atmosphere with a unique temperature profile for
equilibrium. The solar static equilibrium atmosphere exhibits correct
transition-region properties and the accepted base coronal temperature
for the sun's main magnetic spherical harmonic. Steady flows contribute
to the overall pressure, so equilibria with accelerated wind outflows
are possible as well. Flux tubes reflect a mathematical degeneracy in
the form of non-force-free fields, which leads to coupling in general
equilibrium conditions. The equilibrium state characterizes the system
average in usual circumstances and dynamics tend to maintain the MHS
atmosphere. Outflows are produced everywhere external to rigidly held
flux tubes that refill a depleted or cool atmosphere to the equilibrium
gas profile, heating the gas compressively. <P />All Appendices are
only available in electronic form at http://www.edpsciences.org
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Title: Magnetic Compression in Current Sheets for Generating the
Coronal Temperature Structure and Wind Acceleration
Authors: November, Laurence J.
1997SPD....28.0268N Altcode: 1997BAAS...29..905N
A magnetostatic model for current sheets between oppositely directed
potential fields predicts positive and negative pressure fluctuations,
demonstrating the power of the static magnetic field to modify the
ambient gas pressure. The predicted gas pressure fluctuations are
consistent with our observation of 1-5 Mm dark and bright threads, made
at the July 11 1991 eclipse made with the Canada-France-Hawaii Telescope
(November and Koutchmy 1996). The remarkable property that dark threads
are fully evacuated structures indicates that the static magnetic field
is doing work on the overall ambient gas outside of the dark threads
and current-sheet regions. It is straightforward to characterize
the radial pressure function with an added term that contains the
normal radial ambient magnetic-field variation. In the photosphere
the gas pressure is dominated by the nominal atmosphere which we
take as a polytrope in this demonstration of the effect. However
the exponentially decaying polytropic form is soon overtaken by the
magnetic pressure term. The modified atmosphere exhibits the salient
features of the quiet solar atmosphere: a chromospheric temperature
rise, a sharp transition region 1000 to 3000 km above the photosphere,
and a 1.5-2.5 M(deg) K corona whose radial variation closely agrees with
coronal temperature observations. In addition the model can account for
spreading of fields, a magnetic canopy in the chromosphere, a static
outward wind acceleration, and provides an explanation for prominences
as topologically isolated magnetically unmodified atmospheres.
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Title: Intergranular plumes and formation of network bright points.
Authors: Roudier, T.; Malherbe, J. M.; November, L.; Vigneau, J.;
Coupinot, G.; Lafon, M.; Muller, R.
1997A&A...320..605R Altcode:
We discuss the temporal evolution of the photospheric intergranular
lanes using a 1 hour time sequence of white-light images of solar
granulation. The time series was obtained with the 50 cm refractor at
the turret dome of the Pic du Midi Observatory. Analysis reveals the
existence of singularities in the intergranular lanes that we call
“intergranular holes”. Intergranular holes, which have diameters
between 0.24arcsec and 0.45arcsec, are continuously visible for more
than 45 minutes. The holes appear to be systematically distributed at
the periphery of mesogranular and supergranular cells. Our study reveals
the formation of bright points (BPs) in 4 out of 14 cases studied very
close to the intergranular holes, suggesting that intergranular holes
may be the locations where magnetic flux tubes are formed.
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Title: White-Light Coronal Dark Threads and Density Fine Structure
Authors: November, Laurence J.; Koutchmy, Serge
1996ApJ...466..512N Altcode:
High spatial resolution white-light coronal observations from the
eclipse of 1991 July 11 taken with the 3.6 m Canada-France-Hawaii
Telescope on Mauna Kea are the best ever achieved because of the
unique opportunity of observing the totally eclipsed Sun with a large
aperture telescope. Photometric calibration of the photographic data is
verified by the average radial intensity variation, which agrees with
the classical function. Dividing out the average radial variation, we
identify relatively dark and bright fine "threads" with enhanced spatial
power in the range of 1-5 Mm. Spatial filtering using unsharp masking
or "mad-max" algorithms clearly shows relatively dark and bright radial
threads in loops as fine as the resolution limit of about 1 Mm. The main
feature is an arcade of concentric dark and bright threads that extend
above a small prominence just above the limb. A small coronal cavity
near the prominence contains numerous fine dark threads. The relative
electron-density depletion and enhancement required to explain the
observed thread contrast, assuming that they are isolated cylindrically
symmetric structures, is found to be ΔN<SUB>e</SUB>/N<SUB>e</SUB>
∼ ± 100%, indicating that the dark threads are fully evacuated. An
excess of approximately 1 G field strength in stationary non-force-free
magnetic fields can produce the observed thread contrast. Evacuated
threads representing non-force-free magnetic fields introduce special
constraints on the coronal thermodynamics.
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Title: SOLIS - A Modern Facility for Synoptic Solar Observations
Authors: Harvey, J.; Keller, C.; November, L.; NSO Staff
1996AAS...188.6703H Altcode: 1996BAAS...28..934H
SOLIS (Synoptic Optical Long-term Investigations of the Sun) is
a proposed suite of instruments that will modernize and greatly
improve synoptic solar observations carried out by the National
Solar Observatory on behalf the solar and solar-terrestrial physics
communities. The primary scientific goal is to provide fundamental data
necessary to understand the solar activity cycle, sudden energy releases
in the solar atmosphere, and solar spectral irradiance changes. An
operational goal is to produce real-time and near real-time data
for forecasting space weather, and to augment the scientific yield
from space mission such as SOHO and TRACE, and ground-based projects
including RISE and GONG. State-of-the-art instrumentation and data
collection techniques will be employed to enhance both the quality
and quantity of data. A high degree of automation and remote control
will provide faster user access to data and flexible interaction
with the data-collection process. The instruments include a vector
spectromagnetograph that will measure the magnetic field strength and
direction over the full solar disk in 15 minutes, a full disk patrol
delivering digital images in various spectral lines at a high cadence,
a coronal emission line imager and photometer that will provide
photometric and velocity images in at least five spectral lines,
and a Sun-as-a-star precision spectrometer to measure changes in
many spectral lines. The choice of sites for the instruments depends
on potential partnerships with other observatories and the level of
funding that can be obtained. The goal is to place the instruments at
sites with large amounts of sunshine and coronal observing conditions
as appropriate. The SOLIS proposal is currently under review by the
National Science Foundation.
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Title: Dark-Thread Thermodynamics and the Coronal Temperature
Structure
Authors: November, Laurence J.
1996ASPC...95..375N Altcode: 1996sdit.conf..375N
No abstract at ADS
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Title: Observations of a Quiescent Prominence Straddling the Solar
Limb during the Total Eclipse of 11 July 1991
Authors: Gaizauskas, V.; Deluca, E.; Golub, L.; Jones, H. P.;
November, L.
1996mpsa.conf..491G Altcode: 1996IAUCo.153..491G
No abstract at ADS
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Title: Dark Threads and the Coronal Temperature Structure
Authors: November, L. J.
1995AAS...18712205N Altcode: 1995BAAS...27.1454N
High spatial resolution white-light coronal observations from the
eclipse of July 11 1991 taken with the 3.6 m Canada-France-Hawaii
Telescope on Mauna Kea are the best ever achieved because of the unique
opportunity of observing the totally eclipsed sun with a large aperture
telescope. Fine relatively dark and bright threads are found in the
range of sizes of 1-5 Mm. The relative electron-density depletion and
enhancement required to explain the observed thread contrast, assuming
that they are isolated cylindrically symmetric structures, is found
to be 100%, indicating that the dark threads are fully evacuated. They
appear to trace out field lines and probably lie in current sheets. The
threads probably indicate directly the presence of non force-free
magnetic fields requiring approximately 1 gauss strength to produce
their observed contrast. Dark threads having nearly zero internal gas
pressure must map the radial variation of the external gas pressure
and ambient magnetic field strength. Their radial diameter variation
must follow the gas pressure variation near the beta 1 level of the
low corona, and the ambient field higher up where the beta is less than
1. If dark threads are constrained from expansion, they will impose an
isobaric condition on the ambient which leads to a rapid temperature
increase in a hydrostatic corona in thermodynamic balance.
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Title: Warning: Local Correlation Tracking may BE Dangerous to your
(scientific) Health
Authors: Simon, G. W.; Brandt, P. N.; November, L. J.; Shine, R. A.;
Strous, L. H.
1995ESASP.376b.223S Altcode: 1995soho....2..223S; 1995help.confP.223S
No abstract at ADS
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Title: White-Light Coronal Fine Structure and Implications for a
Hot Corona
Authors: November, L. J.
1995SPD....26..912N Altcode: 1995BAAS...27Q.976N
No abstract at ADS
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Title: White-Light Coronal Fine Structure
Authors: November, L. J.; Koutchmy, S.
1995itsa.conf...37N Altcode:
No abstract at ADS
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Title: About small plasmoids propagating in the solar corona
Authors: Koutchmy, S.; Bouchard, O.; Grib, S.; November, L.; Vial,
J. -C.; Gouttebrone, P.; Koutvitsky, V.; Molodensky, M.; Solov'iev,
L.; Veselovsky, I.
1994ESASP.373..139K Altcode: 1994soho....3..139K
No abstract at ADS
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Title: White-Light Coronal Fine Structure
Authors: November, L. J.; Koutchmy, S.
1994AAS...185.9204N Altcode: 1994BAAS...26.1472N
No abstract at ADS
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Title: Inferring the Depth Extent of the Horizontal Supergranular Flow
Authors: November, Laurence J.
1994SoPh..154....1N Altcode:
The 2D horizontal velocity field determined from local correlation
tracking of granulation and its divergence have remarkably different
appearances. The 2D horizontal velocity shows the classical 32 Mm
supergranular cellular outflow bounded by the chromospheric network,
whereas the divergence is dominated by distinct long-lived sources
and sinks of about 7 Mm size. The 2D horizontal velocity shows no
obvious evidence for ≈7 Mm cells, and the divergence exhibits
little power with the ≈32 Mm scale. However, by mass continuity
for a steady 3D flow in a stratified atmosphere, the divergence of
the 2D horizontal component is equal to the vertical velocity divided
by a height scale. Thus the 3D steady solar flow field at the bottom
of the photosphere has a vertical component consisting primarily of
≈7 Mm sources and sinks, which define the 2D cellular-like ≈32 Mm
continuous horizontal outflows.
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Title: Design of precise ultraviolet imaging polarimeters that rely
on in situ calibration
Authors: November, Laurence J.
1994SPIE.2010..192N Altcode:
A telescope design based upon oblique reflections can give an efficient
UV, EUV, or X-ray imaging complete-Stokes polarimeter. Oblique
reflections from mirror surfaces can be efficient giving both
retardation and polarization-analyzing effects. In situ methods using
a linearly polarized source can determine the Jones matrix for the
optical system uniquely. Rotation of the purely polarized source
provides a direct method for calibrating any nondepolarizing optical
system to high accuracy.
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Title: Very High Resolution Analysis of the Dynamics of a Coronal
Plasmoid
Authors: Bouchard, O.; Koutchmy, S.; November, L.; Vial, J. -C.;
Zirker, J. B.
1994scs..conf..593B Altcode: 1994IAUCo.144..593B
The authors present the results of the analysis of a movie taken over a
small field of view in the intermediate corona at a spatial resolution
of 0.5", a temporal resolution of 1 s and a spectral passband of 7
nm. These CCD observations were made at the prime focus of the 3.6 m
aperture CFHT telescope during the 1991 total solar eclipse.
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Title: Long-Lived Convective Flows in Quiet and Active Regions
Authors: November, Laurence J.
1994ASPC...68...78N Altcode: 1994sare.conf...78N
No abstract at ADS
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Title: CFHT eclipse observation of the very fine-scale solar corona
Authors: Koutchmy, S.; Belmahdi, M.; Coulter, R. L.; Demoulin, P.;
Gaizauskas, V.; MacQueen, R. M.; Monnet, G.; Mouette, J.; Noens,
J. C.; November, L. J.
1994A&A...281..249K Altcode:
At the July 11, 1991 solar total eclipse, a modern large optical
telescope, Canada-France-Hawaii telescope (CFHT), was used to
probe the solar corona. The best possible pictures were obtained
with the CFHT, using fast imaging techniques and post-facto image
selection and processing. Several cameras were run during totality
to acquire sub-arcsec spatial resolution white-light images, with
both narrow-band and broad-band filters. The setup and the observing
procedure are described. Preliminary results, together with an
evaluation of the merits of the experiment, are given, as well as a
sample of images. Fine-scale coronal features were observed for the
first time in a time series, confirming the importance of plasmoid-like
activity in the inner corona. The observation of the smallest coronal
feature ever reported is analyzed, giving a typical cross-section of
0.4 +/- 0.1 arcsec. On a larger scale, dark loops around a foreground
prominence are resolved for the first time, suggesting that sheet-like
voids exist above a filament channel.
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Title: Large-scale photospheric motions: first results from an
extraordinary eleven-hour granulation observation
Authors: Simon, G. W.; Brandt, P. N.; November, L. J.; Scharmer,
G. B.; Shine, R. A.
1994ASIC..433..261S Altcode:
No abstract at ADS
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Title: Local-Coherence Averaging for Nonisoplanatic Imaging
Authors: November, L.
1993rtpf.conf..135N Altcode:
No abstract at ADS
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Title: Recovery of the matrix operators in the similarity and
congruency transformations: applications in polarimetry
Authors: November, Laurence J.
1993JOSAA..10..719N Altcode: 1993OSAJ...10..719N
No abstract at ADS
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Title: White-light movies of the solar photosphere from the SOUP
instrument on Spacelab 2 (Advances in Space Research 1986)
Authors: Title, A. M.; Tarbell, T. D.; Simon, G. W.; Acton, L.;
Duncan, D.; Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren,
R.; Morrill, M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Topka,
K.; Harvey, J.; Leibacher, J.; Livingston, W.; November, L.
1993inas.book..100T Altcode:
No abstract at ADS
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Title: The liquid crystal polarimeter for solid-state imaging of
solar vector magnetic fields
Authors: November, Laurence J.; Wilkins, Lawrence M.
1992spo..rept.....N Altcode:
The Liquid Crystal Polarimeter (LCP) is a low-voltage complete
Stokes polarimeter and spectral analyzer designed for measuring solar
vector magnetic fields. The polarimeter consists of polarization and
spectral analyzer sections each containing multiple commercially
available nematic and ferro-electric liquid crystals that are
modulated in phase at up to 31.5 kHz frequency. Used in conjunction
with a Lyot birefringent filter and 2 CCD's, the system provides a
complete polarization/spectral measurement for solid-state direct
imaging of the vector magnetic flux, Doppler velocity, intensity,
and line width in a spectral line. Simultaneous 2 CCD imaging gives
reduced atmospheric seeing systematics, and automatic CCD gain
and dark-current correction. The liquid-crystal design provides a
considerable simplification to previous designs with greatly improved
speed, sensitivity, reliability, and accuracy. The system is used with
a universally tunable Lyot filter (of conventional rotating-element
design) to provide sequential observations in a number of solar lines
to permit calibration of field strength and measurements as a function
of height in the solar atmosphere. An example vector magnetogram is
shown as a proof of concept.
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Title: Evidence of plasmoid ejection in the corona from 1991 eclipse
observations with the Canada-France-Hawaii telescope
Authors: Vial, J. -C.; Koutchmy, S.; Monnet, G.; Sovka, J.; Clark,
C.; Salmon, D.; Purves, N.; Sydserff, P.; Coulder, R.; November, L.
1992ESASP.344...87V Altcode: 1992spai.rept...87V
Observations of the solar corona with a large telescope at high
altitude was fully exploited with the 3.60 m CFHT (Canada France
Hawaii Telescope) in Hawaii, during the 11 Jul. 1991 eclipse,
are reported. Different instruments set up for the eclipse and
preliminary results are given. The moving feature in the corona is
focused upon. Physical conditions in this plasmoid and its origins
are discussed. One of the four cameras installed in the primary focus
was a video charge coupled device camera with a red filter at 637
nm selecting the red line. The power of the telescope allowed for a
good signal in a pixel as small as 0.12 arcsec and a very good time
resolution. The spectral resolution as measured at the Moon limb
was better than one arcsec. During the three minute long sequence,
6000 video images were obtained. Among the fine structures recorded,
a plasmoid about 1500 km wide was seen to ascend and dilute in the
corona. Possible emission mechanisms are discussed. It was found that
both low and relatively high temperature plasmas can be confined in this
ejected plasmoid. Such a small scale phenomenon could be important for
the heating of the corona and should be observed in UV emission lines
in a wide range of temperatures. The high spatial resolution achieved
by Solar Interferometric Mission for Ultrahigh Resolution Imaging and
Spectroscopy (SIMURIS) allows to study the shape, stability and the
diagnostics of such plasmoids in the corona.
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Title: FITS Library: FITS Interactive Task and Shell-Script Library.
Authors: November, L. J.
1992lest.rept..111N Altcode:
The FITS Interactive Task and Shell-Script Library, or just FITS
Library, is a complete image processing that operates within a
normal computer operating system environment. It consists of a few
well-designed specific procedures that work together as task image
"filters" to provide a complete mathematical and graphical capability.
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Title: Eclipse Plans for NSO/SP
Authors: Zirker, J. B.; Koutchmy, S.; Coulter, R. L.; November, L. J.;
Smartt, R. N.
1991BAAS...23.1063Z Altcode:
No abstract at ADS
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Title: Solar polarimetry. Proceedings.
Authors: November, L. J.
1991sopo.work.....N Altcode:
Contents: 1. Instrumentation and techniques. 2. Polarimetric
observations - solar fine structure, flares, coronal measurements,
solar/stellar polarimetry. 3. Polarimetry in the IR. 4. Physical
interpretation.
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Title: Using the Zeeman spectral-polarization symmetry for telescope
calibration.
Authors: November, L. J.
1991sopo.work..149N Altcode:
No abstract at ADS
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Title: Spatial Power Spectra of Mesogranulation and Supergranulation
Velocity
Authors: November, L. J.
1990BAAS...22..840N Altcode:
No abstract at ADS
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Title: On the Location of Footpoints of Sub-Arc Magnetic Structures
in the Quiet Solar Photosphere
Authors: Sivaraman, K. R.; Bagare, S. P.; November, L. J.
1990IAUS..142..192S Altcode:
No abstract at ADS
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Title: Helium resonance lines in the flare of 15 June, 1973
Authors: Porter, Jason G.; Gebbie, Katharine B.; November, Laurence J.
1989SoPh..120..309P Altcode:
Time sequences of He I and He II resonance line intensities at
several sites within the flare of 15 June, 1973 are derived from
observations obtained with the Naval Research Laboratory's Slitless
Spectroheliograph on Skylab. The data are compared with predictions in
six model flare atmospheres based on two values for the heating rate
and three for the flux of photoionizing coronal X-rays and EUV. A
peak ionizing flux more than 10<SUP>3</SUP> times that in the quiet
Sun is indicated. For most conditions in flare kernels the He II
Lα and Lβ lines are found to be formed by collisional excitation,
thereby contributing to the local cooling of the plasma at temperatures
above 6 × 10<SUP>4</SUP> K. Emission in the higher Lyman lines is
generally the result of a mixture of collisional excitation at these
temperatures and photoionization and recombination at temperatures
near 2.5 × 10<SUP>4</SUP> K. We discuss implications for the common
practice of deriving stellar coronal fluxes from He II 1640 Å fluxes
assuming dominance of the recombination mechanism.
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Title: The Vertical Component of the Supergranular Convection
Authors: November, Laurence J.
1989ApJ...344..494N Altcode:
Proper motion measurements of solar granulation made by local
cross-correlation analysis of a 190 minute time series of
white-light images reveal persistent flows with scales of 5-50
Mm. The two-dimensional horizontal flow shows mainly the horizontal
supergranulation, and the divergence of the flow, of the 5-10 Mm
mesogranulation. Time-averaged Doppler vertical velocities in the
photospheric Fe I 5576 A and in the temperature minimum Mg I b2 5173
A lines are correlated with the flow divergence. The time-averaged
chromospheric intensity in Mg I b2 is correlated with the flow
divergence. Fourier spectrum and autocorrelation analyses of the flow
divergence gives a measure of 6.6 Mm in the principal component and
indicates little power at scales larger than 15 Mm.
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Title: Proper motion measurements of solar granulation: the case
for mesogranulation
Authors: November, L. J.
1989hsrs.conf..457N Altcode:
No abstract at ADS
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Title: Line asymmetries and vertical velocities observed with a
narrow-band filter
Authors: Keil, S. L.; Bonaccini, D.; Tamblyn, P.; November, L. J.
1989hsrs.conf..272K Altcode:
No abstract at ADS
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Title: Determination of the Jones matrix for the Sacramento Peak
Vacuum Tower Telescope
Authors: November, Laurence J.
1989OptEn..28..107N Altcode:
The study is concerned with the sampling that is required to determine
the matrix of the unknown device uniquely as a function of its
distinguishable parameters. A unique determination of the device matrix
for an n-element serial system of rotationally distinguishable elements
is given with a number of measurements that scales like n. This number
is much less than is required in a general system having n independent
variables and reflects the separable nature of the serial-device
matrix. A numerical method is used to model a system containing three
rotatable elements, the Sacramento Peak Vacuum Tower Telescope. The
solution accuracy is 2.5 percent and is a general function of all of
the telescope pointing parameters. The matrix solution permits the
recovery of the incoming state of polarization to the system to this
degree of accuracy.
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Title: National Solar Observatory polarimeter
Authors: Dunn, Richard B.; November, Laurence J.; Colley, Stephen A.;
Streander, George W.
1989OptEn..28..126D Altcode:
A general polarimeter for the precise measurement of Stokes intensities
was developed and was used for testing the Sacramento Peak Vacuum Tower
Telescope and other optical instrumentation. The design is based upon
the polarimeter described by Orrall (1971) and Makita et al.(1982),
with some simplifications. A control computer sets parameters in the
integration electronics and provides a simple readout for an experiment
control or analysis computer. Calibration of the polarimeter is defined
by a Mueller matrix for the system; the calibration matrix compensates
for the systematics of the polarimeter. The calibration matrix was
derived using an optical wheel containing many orientations of sheet
polarizers, partial polarizers, and insertable wave plates. The rms of
the calibration solution is about 0.6 percent. The calibration procedure
as it is presently defined limits the accuracy of the polarimeter.
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Title: Details of Large Scale Solar Motions Revealed by Granulation
Test Particles
Authors: Simon, G. W.; November, L. J.; Ferguson, S. H.; Shine, R. A.;
Tarbell, T. D.; Title, A. M.; Topka, K. P.; Zirin, H.
1989ASIC..263..371S Altcode: 1989ssg..conf..371S
No abstract at ADS
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Title: Precise Proper-Motion Measurement of Solar Granulation
Authors: November, Laurence J.; Simon, George W.
1988ApJ...333..427N Altcode:
A powerful cross-correlation method for the precise measurement of the
proper motion of tracers seen on successive images of a time series
of solar granulation is proposed. The time average of the spatially
localized cross correlation is shown to provide a measure of the
displacement that is not biased by atmospheric seeing. The technique is
applied to the analysis of an 80-minute run of white-light observations
made with the Sacramento Peak Vacuum Tower Telescope. From the vector
displacements, solar mesogranulations and supergranulation flows having
spatial scales from 10 to 40 arcsec are found, and it is noted that
the measured flow amplitudes are much larger that the rms 100 m/s
noise which is attributed principally to solar granulation evolution.
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Title: Variability of solar mesogranulation
Authors: Simon, G. W.; November, L. J.; Acton, L. W.; Ferguson, S. H.;
Shine, R. A.; Tarbell, T. D.; Title, A. M.; Topka, K. P.; Zirin, H.
1988AdSpR...8g.169S Altcode: 1988AdSpR...8..169S
From white-light photographs of solar granulation obtained with the
SOUP instrument on Space Shuttle Flight STS-19 we have measured the
motions of granules using local correlation tracking techniques. The
granules are organized into larger-scale structures (mesogranular and
supergranular) which exhibit outflow from upwellings, convergence into
sinks, as well as significant vorticity. Magnetic fields follow these
same flow patterns. We describe these velocity structures, and suggest
that their effect on magnetic field structures may be important to
the solar flare buildup process.
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Title: Correlation Lifetimes of Quiet and Magnetic Granulation from
the SOUP Instrument on Spacelab 2
Authors: Title, A.; Tarbell, T.; Topka, K.; Acton, L.; Duncan, D.;
Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren, R.; Morrill,
M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Simon, G.; Harvey,
J.; Leibacher, J.; Livingston, W.; November, L.; Zirker, J.
1988ApL&C..27..141T Altcode:
The time sequences of diffraction limited granulation images obtained by
the Solar Optical Universal Polarimeter on Spacelab 2 are presented. The
uncorrection autocorrelation limetime in magnetic regions is dominated
by the 5-min oscillation. The removal of this oscillation causes the
autocorrelation lifetime to increase by more than a factor of 2. The
results suggest that a significant fraction of granule lifetimes are
terminated by nearby explosions. Horizontal displacements and transverse
velocities in the intensity field are measured. Lower limits to the
lifetime in the quiet and magnetic sun are set at 440 s and 950 s,
respectively.
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Title: The relation between convection flows and magnetic structure
at the solar surface
Authors: Simon, G. W.; November, L. J.; Acton, L. W.; Title, A. M.;
Tarbell, T. D.; Topka, K. P.; Shine, R. A.; Ferguson, S. H.; Weiss,
N. O.; Zirin, H.
1988AdSpR...8k.133S Altcode: 1988AdSpR...8..133S
We describe recent results from the comparison of data from the Solar
Optical Universal Polarimeter instrument on Spacelab 2 and magnetograms
from Big Bear Solar Observatory. We show that the Sun's surface velocity
field governs the structure of the observed magnetic field over the
entire solar surface outside sunspots and pores. We attempt to describe
the observed flows by a simple axisymmetric plume model. Finally,
we suggest that these observations may have important implications
for the prediction of solar flares, mass ejections, and coronal heating.
---------------------------------------------------------
Title: Photometric photography. I - The multiple-filter method for
characteristic curve measurement
Authors: November, Laurence J.
1988JOSAA...5..351N Altcode: 1988OSAJ....5..351N
A simple method for determining the calibrated response function for
a photographic film is presented; it is called the multiple-filter
method. The measurement is defined by two or more images made of
the same scene with differing attenuations, i.e., different aperture
settings. With known attenuations between the images, the photographic
response function (characteristic curve) can be reconstructed from
these images over the range of intensity available in the scene. A
method for this reconstruction is presented. The method shows an
accuracy of 0.2 millidensity (about 0.00005 intensity) in certain
limits of applicability in numerical simulations. Tests made of actual
photographic samples give internal consistency in their solutions to
about 8 millidensities rms (about 0.002). The photographic tests are
limited by granularity, development uniformity, and defect noise in
the samples.
---------------------------------------------------------
Title: Measurement of a multiple-component serial device of partial
polarizing and retarding elements.
Authors: November, L. J.
1988SPIE..891...91N Altcode:
Remote testing by measurement of the output polarization states
given known input polarization states is used to determine the
matrix of a serial system consisting of n spatially uniform,
nonscattering, rotatable, polarization-modification devices of
constant parameters. With a particular measurement procedure, 6n +3
polarization measurements are sufficient to determine uniquely the
polarization modification matrix of the serial system in all of its
rotational degrees of freedom. A numerical procedure is demonstrated for
inverting measurements taken in a way which did not strictly conform
to the nominal procedure. The numerical procedure is applied to the
Sacramento Peak Vacuum Tower Telescope. The telescope contains three
intermediate and rotationally distinguishable elements which represent
oblique mirror reflections combined with vacuum stressed windows.
---------------------------------------------------------
Title: Large-scale horizontal flows from SOUP observations of solar
granulation.
Authors: November, L. J.; Simon, G. W.; Tarbell, T. D.; Title, A. M.;
Ferguson, S. H.
1987NASCP2483..121N Altcode: 1987tphr.conf..121N
Using high-resolution time-sequence photographs of solar granulation
from the SOUP experiment on Spacelab 2 the authors observed large-scale
horizontal flows in the solar surface. The measurement method is
based upon a local spatial cross correlation analysis. The horizontal
motions have amplitudes in the range 300 to 1000 m/s. Radial outflow of
granulation from a sunspot penumbra into the surrounding photosphere is
a striking new discovery. Both the supergranulation pattern and cellular
structures having the scale of mesogranulation are seen. The vertical
flows that are inferred by continuity of mass from these observed
horizontal flows have larger upflow amplitudes in cell centers than
downflow amplitudes at cell boundaries.
---------------------------------------------------------
Title: Measurement of the Polarization Properties of the NSO/Sunspot
Vacuum Tower Telescope
Authors: November, L. J.; Elmore, D. F.
1987BAAS...19..944N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: On the Relation Between Large-Scale Granular Flows and
Supergranules and Mesogranules
Authors: Simon, G.; Ferguson, S.; Tarbell, T.; Title, A.; Topka, K.;
November, L.; Zirin, H.
1987BAAS...19R.935S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Simultaneous Observations of Emerging Flux from the Big Bear
Solar Observatory and the SOUP Instrument on Spacelab 2
Authors: Topka, K.; Ferguson, S.; Title, A.; Tarbell, T.; Zirin, H.;
Simon, G.; November, L.
1987BAAS...19R.927T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Measurements of Transverse Flows in the Solar Photosphere
from Spacelab 2 SOUP Images
Authors: Tarbell, T. D.; Title, A. M.; Ferguson, S. H.; November,
L. J.; Simon, G. W.
1986BAAS...18R.992T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Precise Proper Motion Measurement of Solar Granulation
Authors: November, L. J.
1986BAAS...18..932N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Image Enhancement Techniques Applied to Solar Granulation Data
Authors: von der Luehe, O.; Dunn, R. B.; November, L. J.
1986BAAS...18..663V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Precise Proper Motion Measurement of Solar Granulation
Authors: November, L. J.; Simon, G. W.; Tarbell, T. D.; Title, A. M.
1986BAAS...18..665N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Measurement of geometric distortion in a turbulent atmosphere
Authors: November, Laurence J.
1986ApOpt..25..392N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The excitation of helium resonance lines in solar flares.
Authors: Porter, J. G.; Gebbie, K. B.; November, L. J.
1986lasf.conf...84P Altcode:
The authors have calculated helium resonance line intensities for
a set of six flare models corresponding to two rates of heating and
three widely varying incident fluxes of soft X-rays. They examine the
differing ionization and excitation equilibria produced by these models,
the processes which dominate the various cases, and the predicted helium
line spectra. The line intensities and their ratios are compared with
values derived from Skylab NRL spectroheliograms for a class M flare,
thus determining (1) which of these models most nearly represents the
density vs. temperature structure and soft X-ray flux in the flaring
solar transition region, and (2) the temperature and dominant mechanism
of formation of the helium line spectrum during a flare.
---------------------------------------------------------
Title: Influence of spatial filtering on possible anisotropies in
solar oscillations.
Authors: Hill, Frank; Haber, Deborah A.; Toomre, Juri; November,
Laurence J.
1986ASIC..169...85H Altcode: 1986ssds.proc...85H
The authors have used full disk Doppler observations of solar
oscillations to compare the amplitudes of sectoral modes propagating
along the equator with those of similar modes propagating along a
great circle aligned with the poles. They find that the amplitudes are
generally not equal for the two classes of modes, but the results are
sensitive to analysis procedures attempting to isolate the different
modes of oscillation. Spatial filtering of the data using spherical
harmonics suggests that greater amplitudes are associated with "polar"
sectoral modes than with "equatorial" sectoral modes.
---------------------------------------------------------
Title: White-light movies of the solar photosphere from the soup
instrument on spacelab 2
Authors: Title, A. M.; Tarbell, T. D.; Simon, G. W.; Acton, L.;
Duncan, D.; Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren,
R.; Morrill, M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Topka,
K.; Harvey, J.; Leibacher, J.; Livingston, W.; November, L.
1986AdSpR...6h.253T Altcode: 1986AdSpR...6..253T
We present initial results on solar granulation, pores and sunspots
from the white-light films obtained by the Solar Optical Universal
Polarimeter (SOUP) instrument on Spacelab 2. SOUP contains a
30-cm Cassegrain telescope, an active secondary mirror for image
stabilization, and a white-light optical system with 35-mm film
and video cameras. Outputs from the fine guidance servo provided
engineering data on the performance of the ESA Instrument Pointing
System (IPS). Several hours of movies were taken at various
disk and limb positions in quiet and active regions. The images
are diffraction-limited at 0.5 arc second resolution and are, of
course, free of atmospheric seeing and distortion. Properties of the
granulation in magnetic and non-magnetic regions are compared and are
found to differ significantly in size, rate of intensity variation,
and lifetime. In quiet sun on the order of fifty percent of the area
has at least one “exploding granule” occurring in it during a 25
minute period. Local correlation tracking has detected several types
of transverse flows, including systematic outflow from the penumbral
boundary of a spot, motion of penumbral filaments, and cellular flow
patterns of supergranular and mesogranular size. Feature tracking has
shown that in quiet sun the average granule fragment has a velocity
of about one kilometer per second.
---------------------------------------------------------
Title: Solar Granulation Movie
Authors: Dunn, R.; November, L. J.
1985tphr.conf...27D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The excitation of helium resonance lines in solar flares
Authors: Porter, J. G.; Gebbie, K. B.; November, L. J.
1985smm..conf.....P Altcode:
Helium resonance line intensities are calculated for a set of six
flare models corresponding to two rates of heating and three widely
varying incident fluxes of soft X-rays. The differing ionization and
excitation equilibria produced by these models, the processes which
dominate the various cases, and the predicted helium line spectra
are examined. The line intensities and their ratios are compared with
values derived from Skylab NRL spectroheliograms for a class M flare,
thus determining which of these models most nearly represents the
density vs temperature structure and soft X-ray flux in the flaring
solar transition region, and the temperature and dominant mechanaism
of formation of the helium line spectrum during a flare.
---------------------------------------------------------
Title: Atmospheric Distortion and Blurring
Authors: November, L. J.; Dunn, R. B.
1985BAAS...17..640N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar granulation movie.
Authors: Dunn, R. B.; November, L. J.
1985MPARp.212...27D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Collages of Granulation Pictures
Authors: Dunn, R. B.; November, L. J.
1985LNP...233...85D Altcode: 1985hrsp.proc...85D
Two small-area selection schemes are applied to CCD observations of
solar granulation. One procedure, referred to as mosaic, divides a
128 x 128 array into 64 subarrays of 16 x 16 pixels; the rms contrast
of the fine structure is measured and compared in order to develop
a mosaic of the subarrays. The second technique, collage, involves
calculating rms values within a sliding Gaussian window and gating
the pixel into the final image. Methods for assessing seeing quality,
which involve the calculation of rms after high-pass filtering,
are examined; a simple high-pass filter or an edge-locating function
can be utilized for filtering. The rms map is then formed from the
convolution of a Gaussian with either the high-pass or the Laplacian
filters. The usefulness of the two procedures is demonstrated by
applying the mosaic and collage processes to data recorded on July 17,
1983 with a CCD device on the NSO/Sac Peak Vacuum Tower Telescope.
---------------------------------------------------------
Title: Helium Resonance Lines in the Solar Flare of 15 June 1973
Authors: Porter, J. G.; Gebbie, K. B.; November, L. J.
1984BAAS...16Q.891P Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Derivation of the universal wavelength tuning formula for a
Lyot birefringent filter
Authors: November, L. J.; Stauffer, F. R.
1984ApOpt..23.2333N Altcode:
A technique for accurate configuration of the spectral tuning model
for a Lyot birefringent filter (LBF) for use in solar astronomy
is presented. The LBF is composed of a series of rotatable tuning
elements, each comprising an entrance polarizer, a birefringent
crystal, and a quarter-wave plate. Entering light is split into
two beams to retain the temporal phase and make the wave phase
accessible. The quarter-wave plate after the birefringent crystal
alters the phase lag into a specific linear polarization angle. It is
shown that the retardation from each tuning element can be resolved by
extrapolating to the retardation of the next spectrally coarser tuning
element if the assumption is made that the effective ratio of tuning
element thicknesses slowly varies in wavelength. The model, applied
to instrumentation at the Sacramento Peak Observatory, results in a
tuning element angular positioning accuracy better than 1 deg and a
spectral positioning better than 0.010 A.
---------------------------------------------------------
Title: The Sacramento Peak Fast Microphotometer.
Authors: Arrambide, M. R.; Dunn, R. B.; Healy, A. W.; Porter, R.;
Widener, A. L.; November, L. J.; Spence, G. E.
1984NASCP2317..243A Altcode:
The Sacramento Peak Observatory Fast Microphotometer translates an
optical system that includes a laser and photodiode detector across
the film to scan the Y direction. A stepping motor moves the film gate
in the X direction. This arrangement affords high positional accuracy,
low noise (0.002 RMS density units), modest speed (5000 points/second),
large dynamic range (4.5 density units), high stability (0.005 density
units), and low scattered light. The Fast Microphotometer is interfaced
to the host computer by a 6502 microprocessor.
---------------------------------------------------------
Title: On the Determination of the Lifetime of Vertical Velocity
Patterns in Mesogranulation and Supergranulation
Authors: Hill, F.; Toomri, J.; November, L. J.; Gebbie, K. B.
1984ssdp.conf..160H Altcode:
Observational studies of the vertical velocities of mesogranulation
and supergranulation provide conflicting results for the lifetimes
of these patterns when analyzed by two different methods. Visual
inspection of the velocity images suggests that mesogranulation has
a lifetime in excess of 2 hours, while cross-correlation methods
imply a lifetime of only about 40 min. For supergranulation, the
correlation technique yields a lifetime of 2.7 hours, far short of the
24 hours found by many other studies considering network structures
or horizontal velocities. The authors consider the possible reasons
for such discrepancies.
---------------------------------------------------------
Title: Radial Velocity Measurements of the Sun Made with a
Birefringent Filter
Authors: November, L. J.
1984ssdp.conf...74N Altcode:
A simple technique is presented for making velocity measurements on
the sun. This uses two simultaneous images formed at the exit of a
Lyot birefringent filter made by substituting the final polarizer in
the filter with a Wollaston polarizing beam splitter.
---------------------------------------------------------
Title: Variability in the power spectrum of solar five-minute
oscillations
Authors: Hill, F.; Toomre, J.; November, L. J.
1983SoPh...82..411H Altcode: 1983IAUCo..66..411H
Two-dimensional power spectra of solar five-minute oscillations
display prominent ridge structures in (k, ω) space, where k is the
horizontal wavenumber and ω is the temporal frequency. The positions
of these ridges in k and ω can be used to probe temperature and
velocity structures in the subphotosphere. We have been carrying out a
continuing program of observations of five-minute oscillations with the
diode array instrument on the vacuum tower telescope at Sacramento Peak
Observatory (SPO). We have sought to establish whether power spectra
taken on separate days show shifts in ridge locations; these may arise
from different velocity and temperature patterns having been brought
into our sampling region by solar rotation. Power spectra have been
obtained for six days of observations of Doppler velocities using the
MgIλ5173 and FeIλ5434 spectral lines. Each data set covers 8 to 11
hr in time and samples a region 256″ × 1024″ in spatial extent,
with a spatial resolution of 2″ and temporal sampling of 65 s. We have
detected shifts in ridge locations between certain data sets which are
statistically significant. The character of these displacements when
analyzed in terms of eastward and westward propagating waves implies
that changes have occurred in both temperature and horizontal velocity
fields underlying our observing window. We estimate the magnitude of
the velocity changes to be on the order of 100 m s<SUP>-1</SUP>; we may
be detecting the effects of large-scale convection akin to giant cells.
---------------------------------------------------------
Title: Precision Tuning and Improved Stability of a Universal
Birefringent Filter
Authors: Stauffer, F. R.; Smith, G. H.; Streander, G. W.; Wilkins,
L. M.; November, L. J.; Smartt, R. N.
1983SPIE..380...77S Altcode:
Basic modifications of the Sacramento Peak Observatory Universal
Birefringent Filter system and resultant major improvements in its
performance are described. Spectral tuning is accomplished by rotating
the nine birefringent elements that comprise the filter. For this,
stepper motors are used under computer control, where one step is
equivalent to a precision of 0.0025 Å (at 7000 A) for the narrowest
bandpass element. The element angles are accurately set for an arbitrary
wavelength by an algorithm derived from known tune solutions. Absolute
wavelength calibration is provided by a He-Ne laser source, while
an integrated monochromator can be used for the same purpose, though
less accurately, throughout the 4100 A to 7000 A spectral range of the
filter. The filter is maintained in a thermally stable environment
controlled to a precision of 0.05° C; any incremental temperature
change in the filter itself can be detected and its effects compensated
by means of a laser calibration. In operation, the filter can typically
be tuned to a selected wavelength in less than is with a precision of
1 mÅ.
---------------------------------------------------------
Title: Relation of Ephemeral Magnetic Regions to the Low Amplitude
Branch of Persistent Vertical Velocities
Authors: Gebbie, K. B.; Toomre, J.; Haber, D. A.; Hill, F.; Simon,
G. W.; November, L. J.; Gurman, J. B.; Shine, R. A.
1982BAAS...14R.939G Altcode: 1982BAAS...14..939G
No abstract at ADS
---------------------------------------------------------
Title: Vertical flows of supergranular and mesogranular scale observed
on the sun with OSO 8
Authors: November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.
1982ApJ...258..846N Altcode:
A program of observations was carried out in order to study the
penetration of supergranular flows over a broad range of heights in
the solar atmosphere. Steady Doppler velocities are determined from
observations of a Si II spectral line using the Ultraviolet Spectrometer
on the Orbiting Solar Observatory 8 (OSO 8) satellite and Fe I and
Mg I lines with the diode-array instrument on the vacuum telescope at
Sacramento Peak Observatory (SPO). The heights of formation of these
spectral lines span about 1400 km or nearly 11 density scale heights
from the photosphere to the middle chromosphere. Steady vertical flows
on spatial scales typical of supergranulation and mesogranulation have
been detected in the middle chromosphere with OSO 8. The patterns of
intensity and steady velocity of granular scale are reproducible in
successive data sets. The patterns appear to evolve slowly over the
9 hr period spanned by six orbits.
---------------------------------------------------------
Title: Solar 5-MINUTE Oscillations as Probes of Structure in the
Subphotosphere
Authors: Hill, F.; Toomre, J.; November, L. J.
1982pccv.conf..139H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Steady flows in the solar transition region observed with SMM
Authors: Gebbie, K. B.; Hill, F.; November, L. J.; Gurman, J. B.;
Shine, R. A.; Woodgate, B. E.; Athay, R. G.; Tandberg-Hanssen, E. A.;
Toomre, J.; Simon, G. W.
1981ApJ...251L.115G Altcode:
Steady flows in the quiet solar transition region have been observed
with the Ultraviolet Spectrometer and Polarimeter experiment on the
Solar Maximum Mission (SMM) satellite. The persistent vertical motions
seen at disk center have spatial rms amplitudes of 1.4 km/s in the C
II line, 3.9 km/s in Si IV, and 4.2 km/s in C IV. The amplitudes of
the more horizontal flows seen toward the limb tend to be somewhat
higher. Plots of steady vertical velocity versus intensity seen at
disk center in Si IV and C IV show two distinct branches.
---------------------------------------------------------
Title: The detection of mesogranulation on the sun.
Authors: November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.
1981ApJ...245L.123N Altcode:
Time averages of velocity measurements at disk center on the quiet sun
reveal the presence of a fairly stationary pattern of cellular flow
with a spatial scale of 5-10 Mm. Such mesogranulation has a spatial rms
vertical velocity amplitude of about 60 m/s superposed on the larger
scale supergranular flows. The lifetimes of mesogranules appear to be
at least 2 hr.
---------------------------------------------------------
Title: Post-Facto Dark Current and Gain Determinations for Solar
Data Obtained with a Diode Array
Authors: Simon, G. W.; November, L. J.
1981BAAS...13Q.878S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar Five-Minute Oscillations as Probes of Velocity and
Temperature Fields
Authors: Hill, F.; Toomre, J.; November, L. J.
1981BAAS...13Q.860H Altcode: 1981BAAS...13..860H
No abstract at ADS
---------------------------------------------------------
Title: Height Dependence of Steady Flows Determined from Coordinated
SMM and SPO Observations
Authors: Gebbie, K. B.; Hill, F.; Toomre, J.; November, L. J.; Simon,
G. W.; Gurman, J. B.; Shine, R. A.; Woodgate, B. E.
1981BAAS...13..914G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Temperature Contrast in Mesogranulation
Authors: November, L. J.
1981BAAS...13..879N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: OSO 8 Observations of Coherent Chromospheric Oscillations
Authors: Hill, F.; Toomre, J.; November, L. J.
1980BAAS...12R.894H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Steady Flows in the Solar Transition Region Observed with
the UVSP Experiment on SMM
Authors: Gebbie, K. B.; Hill, F.; Toomre, J.; November, L. J.; Simon,
G. W.; Athay, R. G.; Bruner, E. C.; Rehse, R.; Gurman, J. B.; Shine,
R. A.; Woodgate, B. E.; Tandberg-Hanssen, E. A.
1980BAAS...12..907G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Lifetime of Solar Mesogranulation
Authors: November, L. J.; Gebbie, K. B.; Hill, F.; Toomre, J.; Simon,
G. W.
1980BAAS...12..895N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mesogranulation and supergranulation in the Sun
Authors: November, Laurence Jay
1980PhDT........64N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mesogranulation -- An Intermediate Scale of Motion on the Sun
Authors: Toomre, J.; November, L. J.; Gebbie, K. B.; Simon, G. W.
1979BAAS...11..641T Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Spectral Diagnostics of a Solar Flare in the Helium Resonance
Lines
Authors: Gebbie, K. B.; November, L. J.; Porter, J. G.
1979BAAS...11..677G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The height variation of supergranular velocity fields
determined from simultaneous OSO 8 satellite and ground-based
observations.
Authors: November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.
1979ApJ...227..600N Altcode:
Results are reported for simultaneous satellite and ground-based
observations of supergranular velocities in the sun, which were made
using a UV spectrometer aboard OSO 8 and a diode-array instrument
operating at the exit slit of an echelle spectrograph attached to a
vacuum tower telescope. Observations of the steady Doppler velocities
seen toward the limb in the middle chromosphere and the photosphere
are compared; the observed spectral lines of Si II at 1817 A and Fe
I at 5576 A are found to differ in height of formation by about 1400
km. The results show that supergranular motions are able to penetrate
at least 11 density scale heights into the middle chromosphere, that
the patterns of motion correlate well with the cellular structure seen
in the photosphere, and that the motion increases from about 800 m/s in
the photosphere to at least 3000 m/s in the middle chromosphere. These
observations imply that supergranular velocities should be evident
in the transition region and that strong horizontal shear layers in
supergranulation should produce turbulence and internal gravity waves.
---------------------------------------------------------
Title: The Variation with Height of Supergranular Velocity Fields
Authors: Gebbie, K. B.; November, L. J.; Toomre, J.; Simon, G. W.
1978BAAS...10Q.672G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Vertical and Horizontal Components of Supergranulation Velocity
Fields Observed with OSO-8
Authors: November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.
1977BAAS....9..337N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Supergranulation Velocity Fields Observed in the Solar
Transition Region with OSO-8
Authors: November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.;
Bruner, E. C., Jr.; Chipman, E. G.; Lites, B. W.; Shine, R. A.;
Orrall, F. Q.; Athay, R. G.; White, O. R.
1976BAAS....8..311N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Heights of Formation of Non-Magnetic Solar Lines Suitable
for Velocity Studies
Authors: Altrock, R. C.; November, L. J.; Simon, G. W.; Milkey, R. W.;
Worden, S. P.
1975SoPh...43...33A Altcode:
Heights of formation of lines that do not exhibit Zeeman splitting
are calculated using an LTE, partial non-LTE, and full non-LTE
approach. Non-magnetic (g=0) lines are valuable for velocity
investigations in quiet-Sun magnetic field regions, and a knowledge
of their formation heights is useful for obtaining three dimensional
velocity profiles in these regions.
---------------------------------------------------------
Title: The Character of 300-Second Oscillators.
Authors: November, L. J.; Simon, G. W.; Worden, S. P.
1975BAAS....7..407N Altcode:
No abstract at ADS
