Author name code: tapping ADS astronomy entries on 2022-09-14 author:Tapping, K.F. ------------------------------------------------------------------------ Title: Solar Quiet (Sq) Waveform Interpolation in the Eigenspace and Its Applications Authors: Li, Qingmou; Boteler, David; Tapping, Kenneth Bibcode: 2021AGUFMSH35H..10L Altcode: Solar Quiet (Sq) waveforms recorded at ground geomagnetic stations reflect solar-terrestrial interactions and have applications in understanding solar irradiation and dynamo action in the ionosphere. Naturally, due to no data being available on active days, Sq records inherently contain gaps. However, currently available interpolation methods can only handle, by their designation, point-oriented or scattered observations. Interpolating the Sq variation with time including the estimated underlying Sq values in the presence of activity is difficult. In this approach, we develop an interpolation method, which extracts and uses the temporal patterns in interpolations to address these requirements. Using this together with the magnetic quiet days identified using the aa-index, we have processed the ground geomagnetic observations recorded in Ottawa, Canada during 1968-2019. We find that our interpolation method is very successful in extracting full waveforms of temporal modes in Sq. Also, the residuals between the observed and interpolated values using our algorithm assessment procedure are acceptable statistically. The Sq signal is highly auto-correlated, the first eigenvalue or eigenvector owns 99.999% of total energy, which assures the success of our algorithm. The algorithm is also able to separate secular and seasonal components hidden in Sq. We further find that the residuals have high correlation with magnetic activity index, such as the ap index, which means that this method can play an important role in separating the quiet and disturbed components of geomagnetic activity. Title: Radio Astronomy and Radio Sources Authors: Tapping, Ken; Pett, Hugh Bibcode: 2018obha.book..338P Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2018obha.book..189T Altcode: No abstract at ADS Title: Changing Relationships Between Sunspot Number, Total Sunspot Area and F10.7 in Cycles 23 and 24 Authors: Tapping, Ken; Morgan, Carly Bibcode: 2017SoPh..292...73T Altcode: This article is an update of a study (Tapping and Valdès in Solar Phys.272, 337, 2011) made in the early part of Cycle 24 using an intercomparison of various solar activity indices (including sunspot number and the 10.7 cm solar radio flux), in which it was concluded that a change in the relationship between photospheric and chromospheric/coronal activity took place just after the maximum of Cycle 23 and continued into Cycle 24. Precursors (short-term variations) were detected in Cycles 21 and 22. Since then the sunspot number index data have been substantially revised. This study is intended to be an update of the earlier study and to assess the impact of the revision of the sunspot number data upon those conclusions. This study compares original and revised sunspot number, total sunspot area, and 10.7 cm solar radio flux. The conclusion is that the transient changes in Cycles 21 and 22, and the more substantial change in Cycle 23, remain evident. Cycle 24 shows indications that the deviation was probably another short-term one. Title: Solar Activity Authors: Tapping, Ken Bibcode: 2017obha.book..189T Altcode: No abstract at ADS Title: Radio Astronomy and Radio Sources Authors: Tapping, Ken Bibcode: 2016obha.book..338T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2016obha.book..189T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2015obha.book..189T Altcode: No abstract at ADS Title: Radio Astronomy and Radio Sources Authors: Tapping, Ken Bibcode: 2015obha.book..338T Altcode: No abstract at ADS Title: Radio Astronomy and Radio Sources Authors: Tapping, Ken Bibcode: 2014obha.book..338T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2014obha.book..189T Altcode: No abstract at ADS Title: The Next Generation of Canadian Solar Flux Monitoring Authors: Tapping, Kenneth F.; Morton, Donald C. Bibcode: 2013JPhCS.440a2039T Altcode: The 10.7 cm solar radio flux (F10.7), provided by the National Research Council of Canada since 1947, is widely used as an index of solar activity and as a proxy for other solar quantities that are harder to measure. Over recent years needs have arisen that are difficult to meet with solar flux measurements at a single wavelength. F10.7 comprises contributions from multiple emission mechanisms. To separate these, multi-wavelength measurements are needed. A new instrument is under construction that will measure fluxes precisely in six bands at 2.8, 3.6, 6.0, 10.7, 18 and 21 cm. Title: Radio Sources Authors: Tapping, Ken Bibcode: 2013obha.book..338T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2013obha.book..189T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2012obha.book..338T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2012obha.book..193T Altcode: No abstract at ADS Title: The Solar Cycle 23 - 24 Minimum. A Benchmark in Solar Variability and Effects in the Heliosphere Authors: White, O.; Kopp, G.; Snow, M.; Tapping, K. Bibcode: 2011SoPh..274..159W Altcode: Given the numerous ground-based and space-based experiments producing the database for the Cycle 23 - 24 Minimum epoch from September 2008 to May 2009, we have an extraordinary opportunity to understand its effects throughout the heliosphere. We use solar radiative output in this period to obtain minimum values for three measures of the Sun's radiative output: the total solar irradiance, the Mg II index, and the 10.7 cm solar radio flux. The derived values are included in the research summaries as a means to exchange ideas and data for this long minimum in solar activity. Title: Did the Sun Change Its Behaviour During the Decline of Cycle 23 and Into Cycle 24? Authors: Tapping, K. F.; Valdés, J. J. Bibcode: 2011SoPh..272..337T Altcode: The activity minimum between the end of cycle 23 and the beginning of cycle 24 was the longest and deepest since at least the beginning of the 20th century. This has led to speculation that the Sun is changing its behaviour. The sunspot number and 10.7-cm solar radio flux indices have traditionally been highly correlated, so a change in the relationship between them might flag at such a change. An examination of this relationship suggests a significant change in the relationship between activity in the photosphere and in the chromosphere/corona happened soon after the maximum of cycle 23 and has continued into cycle 24. However, there are indications of change as early as 1980. Title: Solar Activity Authors: Tapping, Ken Bibcode: 2011obha.book..192T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2011obha.book..341T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2010obha.book..187T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2010obha.book..329T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2009obha.book..193T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2009obha.book..335T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2008obha.book..180T Altcode: No abstract at ADS Title: Radio protection zone evaluation at the Dominion Radio Astrophysical Observatory Authors: Tapping, Ken Bibcode: 2008cosp...37.3150T Altcode: 2008cosp.meet.3150T Increasing use of the radio spectrum by licensed and unlicensed devices, together with the encroachment of housing developments are an issue facing many radio observatories, including the Dominion Radio Astrophysical Observatory (DRAO), located near Penticton in Southern British Columbia. A joint study by Industry Canada (Canada's national spectrum manager), and the National Research Council (Operator of DRAO) is currently in progress to examine protection zone needs and the reliability of the definitions of the zone, and the general level of background noise from growing local communities. The objectives are to produce a definition of a protection zone that is useful in spectrum management to protect the observatory, and to establish how much local community development is acceptable if the observatory is to remain a viable location for radio astronomical observations. This presentation will summarize the results so far in this ongoing study. Title: Radio Sources Authors: Tapping, Ken Bibcode: 2008obha.book..308T Altcode: No abstract at ADS Title: Solar Magnetic Activity and Total Irradiance Since the Maunder Minimum Authors: Tapping, K. F.; Boteler, D.; Charbonneau, P.; Crouch, A.; Manson, A.; Paquette, H. Bibcode: 2007SoPh..246..309T Altcode: We develop a model for estimating solar total irradiance since 1600 AD using the sunspot number record as input, since this is the only intrinsic record of solar activity extending back far enough in time. Sunspot number is strongly correlated, albeit nonlinearly with the 10.7-cm radio flux (F10.7), which forms a continuous record back to 1947. This enables the nonlinear relationship to be estimated with usable accuracy and shows that relationship to be consistent over multiple solar activity cycles. From the sunspot number record we estimate F10.7 values back to 1600 AD. F10.7 is linearly correlated with the total amount of magnetic flux in active regions, and we use it as input to a simple cascade model for the other magnetic flux components. The irradiance record is estimated by using these magnetic flux components plus a very rudimentary model for the modulation of energy flow to the photosphere by the subphotospheric magnetic flux reservoir feeding the photospheric magnetic structures. Including a Monte Carlo analysis of the consequences of measurement and fitting errors, the model indicates the mean irradiance during the Maunder Minimum was about 1 ± 0.4 W m−2 lower than the mean irradiance over the last solar activity cycle. Title: Radio Sources Authors: Tapping, Ken Bibcode: 2007obha.book..273T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2007obha.book..159T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2006obha.book..289T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2006obha.book..175T Altcode: No abstract at ADS Title: Sunspot fragmentation and total solar irradiance modelling Authors: Crouch, A. D.; Charbonneau, P.; Tapping, K. F.; Paquin-Ricard, D. Bibcode: 2005AGUSMSH23B..03C Altcode: Observational evidence suggests that sunspot decay is due, at least in part, to a fragmentation process. We have developed a model for this, where the sunspot fragmentation produces an ensemble of small scale magnetic flux tubes, which themselves can remain at the surface for many days. The number of sunspots emerging at the solar surface varies over the 11 year solar activity cycle. Consequently, the size distribution of magnetic structures is also modulated by the cycle. The simplicity of our model allows us to track the evolution of this distribution over very long time scales (many solar cycles). There are several applications for such a model. For example, to the total solar irradiance, which also varies over the solar cycle. Broadly speaking, the irradiance contribution from different magnetic features depends on their size (large features, such as sunspots, are dark, whereas small flux tubes tend to be bright). By combining this property with our sunspot fragmentation model, we show that the resultant system can produce an irradiance contribution that behaves very much like the observed total solar irradiance. Our model has several input parameters (one crucial example is the actual relationship between the size of a magnetic feature and its brightness). We have used a genetic algorithm to adjust the parameters in order to optimize the agreement between our model and the observations. Will we discuss those results and also comment on the contribution our model makes to the weak field component of solar magnetic flux budget. Title: Solar Activity Authors: Tapping, Ken Bibcode: 2005obha.book..106T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2005obha.book..289T Altcode: No abstract at ADS Title: Radio Sources Authors: Tapping, Ken Bibcode: 2004obha.book..289T Altcode: No abstract at ADS Title: Solar Activity Authors: Tapping, Ken Bibcode: 2004obha.book..104T Altcode: No abstract at ADS Title: Tracing space weather disturbances from the Sun through to their effects on the ground Authors: Boteler, D. H.; Tapping, K. F. Bibcode: 2004cosp...35.4052B Altcode: 2004cosp.meet.4052B Recordings from the RTSN and Penticton radio telescopes are used to investigate the solar eruptions that gave rise to major magnetic disturbances and power system problems on the Earth. Radio flux measurements provide valuable information on the timing and speed of eruptions rising from the Sun's surface. Using the delays in increased flux at different frequencies we determine the speed of eruptions up through different heights in the solar atmosphere. These speeds provide a guide to when each eruption should arrive at the earth which can be correlated with times of geomagnetic disturbances. Times of shock arrivals and the subsequent evolution of the geomagnetic disturbance are examined to identify the specific causes of power system problems on the ground. Title: Book Review: The enigma of sunspots / Floris Books, 2002 Authors: Tapping, Ken Bibcode: 2003Obs...123..233T Altcode: No abstract at ADS Title: S-Component Sources at 21 cm Wavelength in the Rising Phase of Cycle 23 Authors: Tapping, K. F.; Cameron, H. T.; Willis, A. G. Bibcode: 2003SoPh..215..357T Altcode: The Synthesis Radio Telescope at the Dominion Radio Astrophysical Observatory is being used to make a long-term study of the relationship between sources of the slowly-varying component at 21-cm wavelength and the active regions with which they are associated. Although the arc-minute angular resolution of the radio telescope is insufficient to map individual active regions, the unique capability of this radio telescope to map the whole solar disc in a single operation makes it useful for identifying and measuring sources of the slowly-varying component, which at this wavelength are largely due to free-free thermal emission from plasma concentrations trapped in active region magnetic fields. The brightness temperatures of the emission are higher in large, complex active regions, suggesting the plasma slab producing the emission is thicker and/or denser in such regions. We find also that the relationship between the brightness temperature and the size and complexity of the host region is a function of the phase of the 10-13-year solar activity cycle. Title: Sources of the Slowly-Varying Component of Solar Microwave Emission and their Relationship with their Host Active Regions Authors: Tapping, K. F.; Zwaan, C. Bibcode: 2001SoPh..199..317T Altcode: Daily surveys of the solar disc made at 2.8 cm wavelength over the period 1-13 November 1981, complemented by magnetograms and Hα filtergrams, are used to examine the relationship between sources of the slowly varying component of solar radio emission and properties of their host regions. Two classes of source are noted: diffuse and compact. Sources are designated compact when smaller than 40''. The diffuse sources may be explained in terms of free - free thermal emission from trapped plasma in loops overlying the active region. The great majority of compact sources can be accounted for in terms of gyroresonance from thermal electrons in the strong magnetic fields overlying sunspots. A small minority are less amenable to this explanation. They are associated with magnetic complexity and dynamism, lie close to magnetic polarity reversals, and could be non-thermal. Microwave sources are an evolutionary feature common to all but the smallest active regions. Title: Solar Activity Indices Authors: Tapping, K. Bibcode: 2000eaa..bookE2047T Altcode: Solar activity is driven by the temporally and spatially varying distribution of magnetic flux in the photosphere, chromosphere and corona. It covers a range of phenomena at all levels in the solar atmosphere and time-scales ranging from seconds and minutes (SOLAR FLARES and SOLAR CORONAL MASS EJECTIONS), through months (the evolution of ACTIVE REGIONS and SOLAR ACTIVITY COMPLEXES), to the 11 (or... Title: The Low-Resolution DRAO Survey of H I Emission from the Galactic Plane Authors: Higgs, L. A.; Tapping, K. F. Bibcode: 2000AJ....120.2471H Altcode: A survey of H I line emission in the Galactic plane from Galactic longitude l=72.2d to 149° 0, and latitude b=-5.4d to 7.2d, has been made using the 26-m Telescope at the Dominion Radio Astrophysical Observatory. Spectra were observed at 0.2d intervals of longitude and latitude, providing a survey which is fully sampled in the spatial domain. A detailed study of the antenna characteristics of the telescope allowed the correction of the spectra for stray radiation. The spectral resolution is 1.32 km s-1, and the LSR velocity range is -260 to 161 km s-1. The final spectra have an estimated Tb scaling accuracy of 1% and an estimated rms noise in one channel (0.8245 km s-1) of 0.25 K. A region of suspected strong H I self-absorption at l~92deg, b~3deg, has been identified. Comparison with spectra from the Leiden/Dwingeloo Survey is used to estimate the overall accuracy of the stray radiation corrections. This comparison also shows that a small percentage (~1%) of the spectra in the latter survey suffer from calibration errors exceeding 10%. A table of positions of the more discordant spectra is given. Title: The Canadian Galactic Plane Survey - Phase 2. Authors: Landecker, T. L.; Knee, L. B. G.; Brunt, C.; Dewdney, P. E.; Dougherty, S. M.; Galt, J. A.; Gray, A. D.; Higgs, L. A.; Kothes, R.; Purton, C. R.; Roger, R. S.; Tapping, K.; Wallace, B. J.; Willis, A. G.; Brown, J. C.; Gibson, S. J.; Leahy, D. A.; Peracaula, M.; Taylor, A. R.; Wilder, S.; Foster, T.; Routledge, D.; Vaneldik, J. F.; McCutcheon, W. H.; Basu, S.; Johnstone, D. I.; Kerton, C.; Martin, P. G.; Cazzolato, F.; Gagnon, E.; Germain, S.; Ghazzali, N.; Godbout, S.; Joncas, G.; Maschenko, S. Y.; Miville-Deschènes, M. -A.; Pineault, S.; Carignan, C.; St-Louis, N.; Christie, R. A.; Irwin, J. A.; Brar, R.; Fich, M.; Zhang, X. -Z.; Heiles, C. E.; Normandeau, M.; Terebey, S.; Heyer, M. H.; Wendker, H. J.; Beichman, C. A.; Moriarty-Schieven, G. H.; Green, D. A.; Duric, N.; English, J. Bibcode: 1999JRASC..93..182L Altcode: No abstract at ADS Title: Studies of changing patterns of solar activity using the DRAO Synthesis Radio Telescope. Authors: Tapping, K.; Burke, I.; Cameron, H.; Harvey, K.; Zwaan, C. Bibcode: 1999JRASC..93Q.186T Altcode: No abstract at ADS Title: Obituary notice: John R. Smith, 1924-1998 Authors: Tapping, K. Bibcode: 1999JBAA..109...98T Altcode: No abstract at ADS Title: The Sun's energy output and the 10.7 cm flux. Authors: Tapping, K. F. Bibcode: 1998JRASC..92Q.319T Altcode: No abstract at ADS Title: The Canadian Galactic plane survey. Authors: Taylor, A. R.; Gibson, S.; Leahy, D.; Peracaula, M.; Dougherty, S.; Carignan, C.; St-Louis, N.; Fich, M.; Ghazzali, N.; Joncas, G.; Pineault, S.; Mashchenko, S.; Irwin, J.; English, J.; Heiles, C.; Normandeau, M.; Martin, P.; Johnstone, D.; Basu, S.; McCutcheon, W.; Routledge, D.; Vaneldik, F.; Dewdney, P.; Galt, J.; Gray, A.; Higgs, L.; Knee, L.; Landecker, T.; Purton, C.; Roger, R. S.; Tapping, K.; Wallace, B.; Willis, T.; Beichman, C.; Duric, N.; Green, D.; Heyer, M.; Wendker, H.; Zhang, Xizhen Bibcode: 1998JRASC..92R.319T Altcode: No abstract at ADS Title: The Canadian Galactic Plane Survey Authors: English, J.; Taylor, A. R.; Irwin, J. A.; Dougherty, S. M.; Basu, S.; Beichman, C.; Brown, J.; Cao, Y.; Carignan, C.; Crabtree, D.; Dewdney, P.; Duric, N.; Fich, M.; Gagnon, E.; Galt, J.; Germain, S.; Ghazzali, N.; Gibson, S. J.; Godbout, S.; Gray, A.; A. Green, D.; Heiles, C.; Heyer, M.; Higgs, L.; Jean, S.; Johnstone, D.; Joncas, G.; Landecker, T.; Langer, W.; Leahy, D.; Martin, P.; Matthews, H.; McCutcheon, W.; Moriarity-Scheiven, G.; Pineault, S.; Purton, C.; Roger, R.; Routledge, D.; St-Louis, N.; Tapping, K.; Terebey, S.; Vaneldik, F.; Watson, D.; Wendker, H.; Willis, T.; Zhang, X. Bibcode: 1998PASA...15...56E Altcode: The Dominion Radio Astrophysical Observatory (DRAO) is carrying out a survey as part of an international collaboration to image the northe, at a common resolution, in emission from all major constituents of the interstellar medium; the neutral atomic gas, the molecular gas, the ionised gas, dust and relativistic plasma. For many of these constituents the angular resolution of the images (1 arcmin) will be more than a factor of 10 better than any previous studies. The aim is to produce a publicly-available database of high resolution, high-dynamic range images of the Galaxy for multi-phase studies of the physical states and processes in the interstellar medium. We will sketch the main scientific motivations as well as describe some preliminary results from the Canadian Galactic Plane Survey/Releve Canadien du Plan Galactique (CGPS/RCPG). Title: The low-resolution DRAO survey of H I emission from the Galactic plane. Authors: Higgs, L. A.; Davies, M.; Galt, J. A.; Hovey, G. J.; Knee, L. B. G.; Tapping, K. F.; Willis, A. G. Bibcode: 1998JRASC..92R..29H Altcode: No abstract at ADS Title: The Canadian Galactic Plane Survey. Authors: Gibson, S.; Taylor, A. R.; Leahy, A.; Dougherty, S.; Carignan, C.; St. -Louis, N.; Fich, M.; Ghazzali, N.; Joncas, G.; Pineault, S.; Normandeau, M.; Heiles, C.; Irwin, J.; English, J.; Martin, P.; Johnstone, D.; Basu, S.; McCutcheon, W.; Routledge, D.; Vaneldik, F.; Dewdney, P.; Galt, J.; Gray, A.; Higgs, L.; Knee, L.; Landecker, T.; Purton, C.; Roger, R. S.; Tapping, K.; Willis, T.; Moriarty-Schieven, G.; Beichman, C.; Terebey, S.; Duric, N.; Green, D.; Heyer, M.; Wendker, H.; Zhang, Xizhen Bibcode: 1998JRASC..92...28G Altcode: No abstract at ADS Title: The Low-Resolution DRAO Survey of H 1 Emission from the Galactic Plane Authors: Higgs, L. A.; Tapping, K. F. Bibcode: 1997AAS...191.5004H Altcode: 1997BAAS...29R1294H The survey of H 1 emission from the Galactic plane which is currently underway using the Synthesis Telescope at the Dominion Radio Astrophysical Observatory (DRAO), as a major part of the Canadian Galactic Plane Survey, requires single-dish observations of H 1 emission to provide structural information that is missing from the interferometric observations (the so-called ``short spacing'' data). A fast H 1 line survey of about 1000 square degrees of the Galactic plane, which will be used for this purpose, is now being carried out using the DRAO 26-m Telescope. This survey of H 1 line emission will be fully sampled spatially, yielding nearly 25,000 spectra covering the velocity range of -260 km/s to 160 km/s. The survey covers the Galactic longitude range of 72.2arcdeg to 149arcdeg , between Galactic latitudes of -5.4arcdeg and 7.2arcdeg . The spectra have 512 channels with a resolution of 1.3 km/s. The survey will be completed in 1997 and the data will then be corrected for the effects of sidelobe contamination. Initial results of the survey will be presented. Title: The DRAO Galactic Plane Survey Project Authors: Dougherty, S. M.; Dewdney, P.; Galt, J.; Gray, A.; Higgs, L.; Landecker, T.; Purton, C.; Roger, R.; Tapping, K.; Willis, T.; Taylor, A. R.; Leahy, D.; Carignan, C.; St-Louis, N.; Fich, M.; Ghazzali, N.; Irwin, J.; Joncas, G.; Pineault, S.; Martin, P.; McCutcheon, W.; Routledge, D.; Vaneldik, F.; Matthews, H.; Moriarity-Scheiven, G.; Beichman, C.; Terebey, S.; Duric, N.; Green, D.; Heiles, C.; Heyer, M.; Langer, W.; Watson, D.; Wendker, H.; Zhang, X. Bibcode: 1996AAS...189.1704D Altcode: 1996BAAS...28.1295D The Dominion Radio Astrophysical Observatory, in collaboration with a consortium of university astronomers, has begun a survey of the atomic hydrogen and radio continuum emission from our Milky Way galaxy. By constructing a mosaic of 186 synthesis fields, the survey will cover the region 75(deg) < l < 145(deg) and -3(deg) < b < +5(deg) , with angular resolution of ~ 1'. Within this region the observations will yield an atomic hydrogen cube with 256 channels with velocity resolution of 1.2 km s(-1) , Stokes I, Q, U and V continuum images at 1420 MHz and a Stokes I continuum image at 408 MHz. The DRAO survey is part of an international collaboration to image the Milky Way, at a common resolution, in emission from all major constituents of the interstellar medium; the neutral atomic gas, the molecular gas, the ionized gas, dust and relativistic plasma. For many of these constituents the angular resolution of the images will be more than a factor of 10 better than any previous studies. The aim is to produce a database of high resolution, high-dynamic range images of the Galaxy for multi-phase studies of the physical states and processes in the interstellar medium. We present some preliminary images from the survey project as well as highlights of some initial scientific results. Title: Flares and energy dissipation in solar active regions. Authors: Tapping, K. Bibcode: 1996JRASC..90..322T Altcode: No abstract at ADS Title: The DRAO galactic plane survey project. Authors: Taylor, A. R.; Leahy, D.; Carignan, C.; St-Louis, N.; Fich, M.; Ghazzali, N.; Irwin, J.; Joncas, G.; Pineault, S.; Martin, P.; McCutcheon, W.; Routledge, D.; Vaneldik, F.; Dewdney, P.; Dougherty, S.; Galt, J.; Gray, A.; Higgs, L.; Landecker, T.; Purton, C.; Roger, R.; Tapping, K.; Willis, T.; Matthews, H.; Moriarty-Schieven, G.; Crabtree, D.; Beichman, C.; Terebey, S.; Duric, N.; Green, D.; Heiles, C.; Heyer, M.; Langer, W.; Watson, D.; Wendker, H.; Zhang, X. Bibcode: 1996JRASC..90..326T Altcode: No abstract at ADS Title: Schoolyard and backyard experiments in astronomy. Authors: Tapping, K. F. Bibcode: 1995JRASC..89R.160T Altcode: No abstract at ADS Title: Solar active regions and sources of the S-component. Authors: Tapping, K. F. Bibcode: 1995JRASC..89..169T Altcode: No abstract at ADS Title: Imaging the Sun at 21 cm: Budgetting the S-Component Authors: Burke, I. E.; Tapping, K. F. Bibcode: 1995SoPh..157..295B Altcode: On fourteen days in July and August 1992 and June 1993, we used the 7-element synthesis radio telescope at the Dominion Radio Astrophysical Observatory to make full-disc, arc-min resolution images of the Sun at 21 cm, with the objective of budgetting the contributions to the slowly-varying component of solar radio emission. This instrument has the advantage that the mapping field at this wavelength is about 2.5° wide. However, it has also the severe disadvantage that with only 12 hours to record each image, the brightness distribution is severely undersampled. This difficulty, along with solar rotation and declination motion during each observation, required development of special image correction procedures. Title: Discrete microwave sources in solar active regions Authors: Tapping, Kenneth Frank Bibcode: 1995PhDT.......112T Altcode: No abstract at ADS Title: Solar microwave emission and coronal structure. Authors: Tapping, K. F. Bibcode: 1994JRASC..88..253T Altcode: No abstract at ADS Title: Limits to the Accuracy of the 10.7-CENTIMETER Flux Authors: Tapping, K. F.; Charrois, D. P. Bibcode: 1994SoPh..150..305T Altcode: The 10.7 cm flux data, which are widely used as an index of solar activity, are actually spot measurements of the solar flux density at 10.7 cm wavelength, made three times each day, usually at 17:00, 20:00, and 23:00 UT. These values, or the 20:00 UT determination alone, are frequently used as the average flux for that day. Since each spot measurement takes about one hour to make, and the Sun's emissions at that wavelength can vary over time scales shorter than the intervals between the measurements, the data are unavoidably undersampled. Radio emissions from transient events, such as flares, are defined as contaminants of the flux, and largely-empirical procedures have evolved which are used to filter them from the data. Title: A Nearby Star Authors: Tapping, K. Bibcode: 1994JRASC..88....1T Altcode: No abstract at ADS Title: Slowly-Varying Microwave Emissions from the Solar Corona Authors: Tapping, K. F.; Harvey, K. L. Bibcode: 1994svsp.coll..181T Altcode: 1994IAUCo.143P.181T No abstract at ADS Title: Change in the radiative output of the Sun in 1992 and its effect in the thermosphere Authors: White, O. R.; Rottman, G. J.; Woods, T. N.; Knapp, B. G.; Keil, S. L.; Livingston, W. C.; Tapping, K. F.; Donnelly, R. F.; Puga, L. C. Bibcode: 1994JGR....99..369W Altcode: Ground and space measurements of the solar spectral irradiance at radio, visible, UV, and X ray wavelengths show a large decline in the first 6 months of 1992. This sustained drop in the solar output is important in understanding the connection between the emergent magnetic flux on the Sun and the radiative output as well as in understanding the effects of such change in the upper atmosphere of the earth. We present preliminary estimates of the observed changes as the means to spur inquiry into this solar event in the declining phase of solar cycle 22. Typical decreases are 15% in Lyman alpha and 40% in 10.7-cm radio flux. Mass spectrometer and incoherent scatter model calculations at 600 km in the thermosphere indicate a 30% decrease in the temperature and a 3X decrease in the density of the thermosphere near the altitude where both the Upper Atmosphere Research Satellite (UARS) and Hubble Space Telescope (HST) are flying. Decrease of the orbital period of the UARS shows the expected effect of decreasing density at flight altitude. Work in progress indicates that the output change results from the decline in solar magnetic flux to a lower level of activity in the southern hemisphere of the Sun. Title: Mapping the Sun using the DRAO Synthesis Telescope. Authors: Burke, I.; Tapping, K. Bibcode: 1993JRASC..87Q.177B Altcode: No abstract at ADS Title: A model for non-thermal sources in solar active regions. Authors: Tapping, K. Bibcode: 1993JRASC..87..209T Altcode: No abstract at ADS Title: The sources of the slowly-varying component. Authors: Tapping, K. F.; Madden, J. D.; Burke, I. E. Bibcode: 1992JRASC..86..276T Altcode: No abstract at ADS Title: Adaptive potential drops as energy dissipators in solar magnetic structures. Authors: Tapping, K. F. Bibcode: 1991JRASC..85..178T Altcode: No abstract at ADS Title: Using the Radio Schmidt Telescope to Study Solar Active Regions Authors: Tapping, K. F. Bibcode: 1991rst..work..155T Altcode: No abstract at ADS Title: The Solar Radio Astronomy Programme at the National Research Council of Canada Authors: Tapping, K. F. Bibcode: 1991BAAS...23.1039T Altcode: No abstract at ADS Title: A brief history of the Indian River Observatory radio interferometer. Authors: Roy, Frank; Tapping, Ken Bibcode: 1990JRASC..84..260R Altcode: The construction and evolution of a large amateur-built radiotelescope over the past 14 years is presented. To illustrate the improvements in sensitivity achieved during the project, examples of observations made with the instrument are described. Title: The Origin of the 10.7-CM Flux Authors: Tapping, K. F.; Detracey, B. Bibcode: 1990SoPh..127..321T Altcode: We propose that when all sources on the solar disc are taken into account, the S component at 10.7 cm wavelength is dominated by thermal free-free (bremsstrahlung) emission. It is not produced only in the vicinity of sunspots; more than 60% of the total flux may be due to a widely-distributed emission associated with the hot complexes of activity. Using a model for the solar atmosphere based upon an assumption of weak (or vertical) magnetic fields, the spectrum of the S-component is calculated and its sensitivity to changes in the model parameters investigated. Variation of the thicknesses of the chromosphere, transition region and mixed zone cause only small changes in the S-component spectrum; there is a much stronger dependence upon the plasma density, particularly at the base of the corona. The behaviour of the S-component at 10.7 cm wavelength is examined in more detail. We find that the largest contribution to the 10.7 cm flux originates in the low corona, that structural changes affect it only slightly, but that it is strongly density-related. This dependence upon few quantities, together with its relative localization in the low corona, contributes to the usefulness of the 10.7 cm flux as an index of solar activity. Title: Relationships Between Active Region Emissions at 2. 8cm and Indicators of Dynamic Processes Authors: Tapping, K. F. Bibcode: 1989BAAS...21..828T Altcode: No abstract at ADS Title: The 10.7-cm microwave observations of AR 5395 and related terrestrial effects Authors: Gaizauskas, V.; Hughes, T. J.; Tapping, K. F. Bibcode: 1989dots.work..242G Altcode: The 10.7 cm flux patrols in Canada recorded 4 Great Bursts (peaks greater than 500 sfu) during the disk passage of AR 5395 in March 1989. The Great Bursts of 16 and 17 March were simple events of great amplitude and with half-life durations of only several minutes. Earlier Great Bursts, originating on 6 March towards the NE limb and on 10 March closer to the central meridian, belong to an entirely different category of event. Each started with a very strong impulsive event lasting just minutes. After an initial recovery, however, the emission climbed back to level as greater or greater than the initial impulsive burst. The events of 6 and 10 March stayed above the Great Burst threshold for at least 100 minutes. The second component of long duration in these cases is associated with Type 4 continuum emission and thus very likely with CMEs. Major geomagnetic disturbances did not occur as a result of the massive complex event of 6 March or the two simple but strong events of 16 and 17 March. But some 55 hours after the peak in the long-enduring burst of 10 March, a storm began which qualifies as the fourth strongest geomagnetic storm in Canada since 1932. The vertical component of the earth's field measured during the storm by a fluxgate magnetometer at a station in Manitoba is presented. Within a minute of the sudden commencement of this storm, a series of breakdowns began in the transmission system of Hydro-Quebec which resulted in a total loss of power, on a bitterly cold winter's day, for at least 10 hours. The loss of power provoked an enormous outcry from the public resulting in the power utilities being more receptive to the need to monitor solar as well as geomagnetic activity. Title: The Origins of the 10.7-CM Solar Flux Authors: Tapping, K. F.; Gaizauskas, V. Bibcode: 1988JRASC..82..280T Altcode: No abstract at ADS Title: Compact Sites of Microwave Emission at 2.8 Centimeter Wavelength inside Solar Active Regions Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1988ApJ...325..912G Altcode: The authors have located the positions of 59 hot, compact sources of 2.8 cm emission in 28 active regions with respect to photospheric and chromospheric structures. The same regions were photographed at high spatial resolution on the same days through a wavelength-scanning Hα filter. Almost 90% of these compact sources are associated with either a plage or a polarity reversal (or both together); they are found in just part of a plage (or polarity reversal) which may be one of several in the same active region. The authors propose that the observed properties of these compact sources can be explained in terms of emission from current-driven instabilities which are excited by evolutionary stresses acting on active regions. Title: The Thermal Contribution to the 10.7 cm Flux Authors: Tapping, K. Bibcode: 1988srov.proc..135T Altcode: No abstract at ADS Title: Search for X-Rays from the Region of the Aries-Perseus Flasher Authors: Lewin, Walter H. G.; van Paradijs, Jan; Damen, Eugene; Jansen, Fred; McCall, Marshall L.; Feldman, P. A.; Tapping, K. F. Bibcode: 1987AJ.....94..429L Altcode: The region containing the Perseus flasher (Katz et al., 1986) was observed for 5.4 hr with the EXOSAT observatory. Upper limits (2 σ levels of confidence) to a point source with a steady X-ray flux were 2×10-12erg cm-2s-1 (0.1 - 2 keV) and 6×10-12erg cm-2s-1 (1 - 20 keV). Upper limits (4 σ level of confidence) to X-ray flashes of ≡1 s duration were 4×10-9erg cm-2s-1 (0.1 - 2 keV) and 7×10-10erg cm-2s-1 (1 - 20 keV). Title: Compact Sources of Microwave Emission at 2.8 cm Wavelength Inside Solar Active Regions Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1987BAAS...19..942G Altcode: No abstract at ADS Title: Microwave Emission from Evolving Active Regions Authors: Tapping, K. F. Bibcode: 1987BAAS...19Q.943T Altcode: No abstract at ADS Title: Recent solar radio astronomy at centimeter wavelengths: the temporal variability of the 10.7-cm flux. Authors: Tapping, K. F. Bibcode: 1987JGR....92..829T Altcode: Studies made by means of high-resolution radio telescopes indicate that solar centimetric emission contains contributions from many different sources and involves more than one radiation mechanism. Two emission components have been identified: bright, compact sources and weaker, diffuse emission which is distributed over the plage and surrounding areas of enhanced magnetic field. There is evidence for the occurrence of weaker but widely distributed radiation from elements of the active network. The good correlation between the 10.7-cm flux and shorter-wavelength indicators of solar activity, such as Ca II emission, suggests that gyromagnetic processes contribute little to the total centimetric flux. If the 10.7-cm flux is predominantly thermal (free-free) emission, its intensity will be a measure of the total amount of magnetic flux emerging through the photosphere and supporting density enhancements in the lower solar atmosphere. Title: Solar VLBI of Compact Transient Sources Authors: Tapping, K. F. Bibcode: 1986SoPh..104..199T Altcode: Very Long Baseline Interferometry offers the only technique for resolving the transient compact sources which, according to an increasing weight of observational and theoretical evidence, occur during solar flares. In this paper we discuss the problems of applying VLBI to observing the Sun, the results obtained so far and how the technique may be effectively employed in future studies of compact emission structures in solar flares. Title: A double layer model for solar X-ray and microwave pulsations. Authors: Tapping, K. F. Bibcode: 1986NASCP2449..445T Altcode: 1986rfsf.nasa..445T The wide range of wavelengths over which quasi-periodic pulsations have been observed suggests that the mechanism causing them acts upon the supply of high energy electrons driving the emission processes. A model is described which is based upon the radial shrinkage of a magnetic flux tube. An instability takes place in the tube throat, resulting in the formation of a potential double layer, which then accelerates electrons and ions to MeV energies. The double layer can be unstable, collapsing and reforming repeatedly. The resulting pulsed particle beams give rise to pulsating emissions which are observed at radio and X-ray wavelengths. Title: Solar VLBI. Authors: Tapping, K. F.; Kuijpers, J. Bibcode: 1986NASCP2449..211T Altcode: 1986rfsf.nasa..211T In April, 1981, radio telescopes at Dwingeloo (The Netherlands) and Onsala (Sweden) were used as a long-baseline interferometer at a wavelength of 18 cm. The baseline of 619 km gave a spatial resolution on the Sun of about 45 km. The major problems of Solar Very Long Baseline Interferometry are discussed. Title: Rapid spectral and flux time variations in a solar burst observed at various dm-mm wavelengths and at hard X-rays. Authors: Zodivaz, A. M.; Kaufmann, P.; Correia, E.; Costa, J. E. R.; Takakura, T.; Cliver, E. W.; Tapping, K. F. Bibcode: 1986NASCP2449..171Z Altcode: 1986rfsf.nasa..171Z A solar burst was observed with high sensitivity and time resolution at cm-mm wavelengths by two different radio observatories; with high spectral time resolution at dm-cm wavelengths by patrol instruments; and at hard X-rays. The event appears to be build up by a first major injection of softer particles followed by other injections of harder particles. Ultrafast time structures were identified as superimposed to the burst emission at the cm-mm high sensitivity data and at X-rays, with predominant repetition rates ranging 2.0 - 3.5 Hz. Title: A torsional wave model for solar radio pulsations. Authors: Tapping, K. F. Bibcode: 1983SoPh...87..177T Altcode: One of the widely accepted models for solar radio pulsations invokes radial oscillations of a magnetic flux tube. Due to acoustic, radiative damping, this theory does not easily explain the long length of the pulse trains, the large modulation depths or the great stability of the pulse repetition rate often observed. Torsional waves efficiently modulate synchrotron emission, and since they do not undergo radiative damping, can produce stable pulse repetition rates and long pulse trains. Title: VLBI of solar flares Authors: Tapping, K. F.; Kuijpers, J.; Kaastra, J. S.; van Nieuwkoop, J.; Graham, D.; Slottje, C. Bibcode: 1983A&A...122..177T Altcode: From April 28 to May 3, 1981, a VLBI experiment was carried out to observe small spatial scales in the initial energy release in solar flares. The 25 m radio telescope at Onsala (Sweden) and Dwingeloo (Netherlands) were used; the observing wavelength was 18 cm. Simultaneous observations were made using the Westerbork Synthesis Radio Telescope at a wavelength of 6 cm. The VLBI baseline was 619 km. During the observing period, three weak outbursts were observed, none yielding any strong correlated signals. However, the statistical behaviour of the correlator output over the range of delay channels shows significant indications of a correlated signal having a signal to noise ratio of order unity, during the impulsive spikes preceding the main phase of the event. Title: A Beam Ratio Technique for Microwave Observation of S-Component Sources Authors: Tapping, K. F. Bibcode: 1983SoPh...83..179T Altcode: The fluctuations in the tropospheric attenuation constitute a major problem when S-component source variations are studied. On records made by means of `single beam' antenna systems, separating solar variations from spurious effects can be very difficult. The twin-beam, beam ratio technique circumvents this problem by deriving a ratio with respect to a reference beam which is identically affected by the tropospheric attenuation and by receiver gain variations. Title: Very long baseline interferometry of solar flares Authors: Kuijpers, J.; Tapping, K. F.; Graham, D. Bibcode: 1983ASSL..102..339K Altcode: 1983ards.proc..339K; 1983IAUCo..71..339K An experimental VLBI search for the occurrence of subarcsecond microwave emission centers as tracers of the initial energy release in solar flares is discussed. The observations extended over the period April 28 to May 3, 1981, during which period three weak outbursts occurred. No large correlations were observed, but a strong indication of an unresolved source with a signal to noise ratio of order unity was found during the impulsive bursts preceding the main phase of one event. During the impulsive bursts the spread in number of the channel which showed the maximum correlation amplitude was reduced significantly below the value for random behavior. A clear reduction in the amount of scatter from the expectation value during impulsive bursts is shown. The derived brightness temperature is of the order 10 to the 12th K; the probable error box for the source position is shown. Title: Combined radio-optical observations of active solar regions associated with the S-component of solar miocrowave emission. Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1980JRASC..74..358G Altcode: No abstract at ADS Title: Long-lived microwave pulsations observed in a complex solar active region Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1980ApJ...241..804G Altcode: Microwave pulsations were detected on Sept. 13, 1977 in the intense emission from a compact microwave source associated with the large, slowly rotating, and magnetically complex solar active region, McMath 14943. These pulsations persisted over 5-1/2 hours, with the dominant repetition rate remaining close to 0.4 Hz; they were not associated with flare activity. The core of the microwave emission was located over a plage rather than over the major spot in the region. A mechanism for the pulsating source is proposed in which radial oscillations in an arched magnetic flux tube modulate the gyrosynchrotron emission from high energy electrons trapped in the tube. Title: Persistent Quasi-Periodic Microwave Pulsations from a Non-Flaring Compact Source in a Complex Active Region Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1980BAAS...12..515G Altcode: No abstract at ADS Title: The February 1979 Solar Eclipse on Short Wave Authors: Wiest, Chip; Tapping, Ken Bibcode: 1980JRASC..74L..40W Altcode: No abstract at ADS Title: Location of compact microwave sources with respect to concentrations of magnetic field in active solar regions Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1980IAUS...91...33G Altcode: From September 1977 to July 1979, 28 active regions with compact microwave sources were examined by joint optical and radio observations. In 11 of the 28 observed regions, the compact microwave sources varied in intensity with time-scales from minutes to several hours by as much as 50%, neglecting obviously impulsive events. The brightness temperatures of the sources at 2.8 cm were in the range 30,000 to more than 10 million K; for six sources, the brightness temperatures exceeded 2 million K. The results cannot be explained in terms of thermal emissive processes. Title: Detection of a Compact Microwave Source in an Emerging Active Region Authors: Gaizauskas, V.; Tapping, K. F. Bibcode: 1979BAAS...11..420G Altcode: No abstract at ADS Title: The Ottawa Centre's Radio Telescope Authors: Tapping, Ken Bibcode: 1979JRASC..73L..12T Altcode: No abstract at ADS Title: Meter wavelength pulsating bursts during the May 21, 1072, solar noise storm. Authors: Tapping, K. F. Bibcode: 1978SoPh...59..145T Altcode: During the May 21, 1972, noise storm, flux density measurements were made, at a frequency of 140 MHz, of 14 pulsating bursts. These comprised trains of up to 20 pulses, having pulse repetition rates of up to 15 s−1. Title: Amateur Radio Astronomy Part I Authors: Tapping, K. F. Bibcode: 1978JRASC..72L...5T Altcode: No abstract at ADS Title: Amateur Radio Astronomy Part II Authors: Tapping, K. F. Bibcode: 1978JRASC..72L..22T Altcode: No abstract at ADS Title: Amateur Radio Astronomy Part III Authors: Tapping, K. F. Bibcode: 1978JRASC..72L..38T Altcode: No abstract at ADS Title: Amateur Radio Astronomy Part IV Authors: Tapping, K. F. Bibcode: 1978JRASC..72L..60T Altcode: No abstract at ADS Title: The Distribution Of Solar Radio Flux: Levels And Oscillatory Bursts Authors: Tapping, K. F. Bibcode: 1976JBAA...87...51T Altcode: 1976JBIS...87...51T A large collection of regular solar radio measurements conducted over 11 years at six observing frequencies is used to derive models for the rates of occurrence of type I and type IV events at discrete observing frequencies. Variations of the occurrence distribution parameter with frequency are examined, and it is found that normalized flux-density values have an exponential distribution. A linear relation between distribution parameter and frequency is obtained for frequencies above 120 MHz. The observed deviation from this relation below 120 MHz is attributed to the possibility that type I and type IV emissive centers are no longer optically thick below about 100 MHz. Two typical examples of oscillatory bursts recorded at 136 MHz are discussed, and it is suggested that these bursts could be caused by the same mechanism responsible for type III events; i.e., excitation of coronal plasma by jets of high-energy electrons produced in the lower corona or the chromosphere. The origin of the high-energy electrons is considered. Title: Solar and solar system activity. Authors: Langton, R. J. J.; Smith, J. R.; Tapping, K. F. Bibcode: 1973JBAA...83..138L Altcode: No abstract at ADS Title: Solar and solar system activity. Authors: Langton, R. J. J.; Smith, J. R.; Tapping, K. F. Bibcode: 1972JBAA...82..379L Altcode: No abstract at ADS