TEMPORAL VARIATIONS IN ZONAL FLOWS

摘要

With more than half a solar-cycle worth of helioseismicrndata now available, we revisit the question of how solarrnrotation rate changes with time. The bands of faster andrnslower than average rotation rate are found to move to-wardsrnthe equator at low latitudes, while at high latitudesrnthey move towards the poles. The low latitude bands alsornmove upwards with time, and they extend almost to thernbase of the convection zone. We find no significant tem-poralrnvariation in the rotation rate in the tachocline re-gion.