Temporal variation in the solar rotation rate during the last one decade

Abstract

With over a decade's worth of helioseismic data now available we study the temporal variation in rotation rate in the solar interior. Apart from the well known latitudinal shift in zonal flow pattern, we also find that at low latitudes the pattern shifts upwards with time. This pattern can be compared with predictions of solar dynamo theories. We also examine possible periodic variations in the rotation rate in the tachocline region.