SOHO CoRoT Kepler Picard SDO GONG

Temporal variations of high-degree solar acoustic modes from GONG and MDI


Burtseva Olga


National Solar Observatory


Local helioseismology
Auteur(s) supplémentaire(s)S. C. Tripathy (1), R. Howe (1), K. Jain (1), F. Hill (1), R. Bogart (2) and M. C. Rabello-Soares (2)
Institution(s) supplémentaire(s)(1) National Solar Observatory, 950 N. Cherry Ave., Tucson, AZ 85719, USA; (2) HEPL, Stanford University, 455 Via Palou, Stanford, CA 94305, USA


The global and local analysis of solar acoustic modes has shown that the mode amplitudes and lifetimes are anti-correlated with the solar activity level, and depend strongly on the local magnetic flux. Most of the analysis has been carried out for active regions, while the solar cycle behavior of quiet-Sun regions is not well understood. We study temporal variations in the amplitudes and widths of high-degree acoustic modes in the quiet-Sun areas along with the areas including active regions by applying ring-diagram technique to the GONG+ and MDI Dopplergrams during the declining phase of cycle 23. Temporal variations of the acoustic mode parameters in the quiet Sun could be caused by changes in the convective properties and magnetic fields connected to the convective motions. We also analyze the temporal variations of the magnetic activity indexes computed from full-disk magnetograms.
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