Ekman pumping velocity and depth of surface mixed layer of the north Indian Ocean during southwest monsoon

Effect of Ekman pumping velocity on the variability of mixed layer depth was studied using sub-surface and marine meteorological data. Relatively shallow mixed layer is found during May due to the influence of summer heating. From June onwards, in general, deep mixed layer is found in the regions of negative Ekman pumping velocity, while shallow layer is observed in the regions of positive Ekman pumping velocity. However, during August and September in the Arabian Sea, horizontal advection of surface waters and convective overturning caused by buoyancy flux along with the stress curl field, appear responsible for the deepening of the mixed layer. Profound variations in both Ekman pumping velocity and mixed layer depth are noticed over the Arabian Sea in contrast to the Bay of Bengal.