Time variability of rotation in solar convection zone from SOI-MDI

The variation of rotation in the convection zone over a period of two years from mid-1996 is studied using inversions of SOI-MDI data. We confirm the existence of near-surface banded zonal flows migrating towards the equator from higher latitudes, and reveal that these banded flows extend substantia lly beneath the surface, possibly to depths as great as 70 Mm (10% of the s olar radius). Our results also reveal apparently significant temporal varia tions in the rotation rate at high latitudes and in the vicinity of the tac hocline over the period of study.