Statistical Properties of Magnetic Separators in Model Active Regions

1999 ◽  
Vol 522 (2) ◽  
pp. 1117-1132 ◽  
Author(s):  
Brian T. Welsch ◽  
Dana W. Longcope
Keyword(s):  
Active Regions ◽  
Statistical Properties

Statistical properties of X-class flares and their relationship with super active regions during solar cycles 21–23

2014 ◽  
Vol 350 (2) ◽  
pp. 443-447 ◽  
Author(s):  
Guiming Le ◽  
Xingxing Yang ◽  
Yonghua Liu ◽  
Peng Li ◽  
Zhiqiang Yin ◽  
...  
Keyword(s):  
Active Regions ◽  
Statistical Properties ◽  
Solar Cycles

scholarly journals Statistical Properties of the Energy Release in Emerging and Evolving Active Regions

2002 ◽  
Vol 575 (2) ◽  
pp. L87-L90 ◽  
Author(s):  
Loukas Vlahos ◽  
Tassos Fragos ◽  
Heinz Isliker ◽  
Manolis Georgoulis
Keyword(s):  
Energy Release ◽  
Active Regions ◽  
Statistical Properties

Synoptic Charts of the Solar Eclipses of 1990 and 1991

1994 ◽  
Vol 144 ◽  
pp. 517-521
Author(s):  
Z. Mouradian ◽  
G. Buchholtz ◽  
G. Zlicaric
Keyword(s):  
Solar Limb ◽  
Active Regions ◽  
Solar Eclipses ◽  
Coronal Structures

AbstractThe synoptic charts of solar rotations 1831 and 1844 have been drawn up, corresponding to the eclipses of 22 July 1990 and 11 July 1991. These charts contain the active regions and the filaments, and show the position of the solar limb, at the time of the eclipse. They are for use in studying the coronal structures observed during these eclipses. The variation of these structures is given in the table. The last section of the article contains a formula for identifying the structures out of the limb.

Solar Corona Investigation by the Coronal Line Photometer at Lomnický Peak

1994 ◽  
Vol 144 ◽  
pp. 431-434
Author(s):  
M. Minarovjech ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
Time Resolution ◽  
Active Regions ◽  
High Time ◽  
High Time Resolution ◽  
List Type ◽  
Type Number ◽  
Coronal Line ◽  
Global Cycle

AbstractThis paper deals with a possibility to use the ground-based method of observation in order to solve basic problems connected with the solar corona research. Namely:1.heating of the solar corona2.course of the global cycle in the corona3.rotation of the solar corona and development of active regions.There is stressed a possibility of high-time resolution of the coronal line photometer at Lomnický Peak coronal station, and use of the latter to obtain crucial observations.

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Interpretation of the Filament Depression at Millimetric and Centimetric Wavelengths

1979 ◽  
Vol 44 ◽  
pp. 131-134
Author(s):  
A. Raoult ◽  
P. Lantos ◽  
E. Fürst
Keyword(s):  
Radio Telescope ◽  
Active Regions ◽  
Simple Shape ◽  
Quiet Sun ◽  
Unstable Process

The depressions at centimetric and millimetric wavelengths associated with the filaments are studied using already published maps as well as unpublished observations from the Effelsberg 100 m radio telescope of the M.P.I., Bonn. The study has been restricted to large Ha quiescent prominences of relatively simple shape, situated far from the limb and from active regions. The data has been reduced employing one method whose main characteristics are choice of a local quiet sun definition and avoidance of the unstable process of deconvolution.

The Hemispheric Sign Rule of Current Helicity during the Rising Phase of Cycle 23

2000 ◽  
Vol 179 ◽  
pp. 303-306
Author(s):  
S. D. Bao ◽  
G. X. Ai ◽  
H. Q. Zhang
Keyword(s):  
Solar Cycle ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Active Regions ◽  
Hemispheric Preference ◽  
Current Helicity

AbstractWe compute the signs of two different current helicity parameters (i.e., αbestandHc) for 87 active regions during the rise of cycle 23. The results indicate that 59% of the active regions in the northern hemisphere have negative αbestand 65% in the southern hemisphere have positive. This is consistent with that of the cycle 22. However, the helicity parameterHcshows a weaker opposite hemispheric preference in the new solar cycle. Possible reasons are discussed.

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