Two sets of direct velocity measurements were taken, concurrent with hydrographic data, in the bottom waters of the northern Somali Basin in June and September, 1995. The velocities indicate a temporal flow reversal in the bottom circulation, which is consistent with the changing density structure between the sections. In June, there is evidence of a southward Deep Western Boundary Current with a transport of 5 Sv. By September, flow close to the boundary is northward, with a transport of 2.6 Sv. Furthermore, the deep density gradient across the interior of the Somali Basin also changes between occupations, implying a cyclonic circulation in June and anticyclonic flow in September. Rossby wave activity is high in this region during the southwest monsoon, yet there is also evidence of a strong barotropic component to the Great Whirl in September, which may cause the reversal in the abyssal circulation.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)