Changes in solar dynamics from 1995 to 2002

Abstract

Data obtained by the GONG and MDI instruments over the last 7 years are used to study how solar dynamics-both rotation and other large scale flows-has changed with time. In addition to the well-known phenomenon of bands of faster and slower rotation moving toward the equator and pole, we find that the zonal flow pattern rises upward with time. Like the zonal flows, the meridional flows also show distinct solar activity-related changes. In particular, the antisymmetric component of the meridional flow shows a decrease in speed with activity. We do not see any significant temporal variations in the dynamics of the tachocline region where the solar dynamo is believed to be operating.