Current structure and kinetic energy of the abyssal waters in the Central Indian Ocean Basin

Abstract

Analysis of abyssal currents measured at 7 levels viz., 4, 8, 15, 30, 50, 100 and 500 mab during October 1996-April 1997 at 10 degrees 01'S, 76 degrees E in the Benthic Disturbance Experiment Site (BDES) in the Central Indian Ocean Basin is presented. Monthly mean currents showed a general SSE flow and suggested seasonal variability in the flow pattern with a reversal in January. The variation of 6 month-mean current speed indicated near-bottom intensification of the flow at 50 mab and presence of Bottom Ekman Layer (BEL) below 50 mab. Above BEL the total KE at each depth was dominated by eddy KE resulted from synoptic scale (12-15 day period) motions. In the BEL, the intertial and tidal oscillations contributed to the eddy KE. It is found that BDES was highly energetic (2-3 folds) compared to a nearby location approx 1000 km to the west of BDES.