Circulation and watermass structure in the Central Arabian Sea during December 1982

Abstract

After the cessation of the SW monsoon over Arabian Sea, the North Equatorial Current sets strongly and the low saline waters from the Bay of Bengal and the equatorial Indian Ocean penetrate into the Arabian Sea. This results in strong horizontal salinity gradients in the upper layers due to the mixing of the Persian Gulf, Bay of Bengal and Arabian Sea High Salinity Waters. The low salinity water is found to originate in the Andaman Sea and its thermohaline index has been derived as T = 18.6 degrees C and S = 34.5 x 10 -3 and can be traced on the 300 cl/t isanosteric surface. The mixing patterns in the central Arabian Sea have been studied by constructing the triangles of mixing. It is found that, the vertical mixing is dominant along the core of the Persian Gulf Watermass