On the solar rotation rate in the upper convection zone

Abstract

We present results on variation in rotation rate in the upper convection zone using data from GONG and MDI/SOHO covering a period of more than four years. We find that the first few odd-order splitting coefficients vary systematically with the solar cycle. The rotation rate near the solar surface calculated from analytical methods agrees well with that of inversion techniques. The residual rotation rate in the outer layers seem to be correlated with the solar activity.