Moored buoy observations in Arabian Sea warm pool

Abstract

Time series observations from four moored data buoys in the south eastern Arabian Sea for a period of four months (March - June 2003) are utilized to study the characteristics of warm pool. The moored buoy observations show fair weather conditions in the pre-monsoon period with weak variable winds and calm sea conditions. High SST has been observed during the pre-monsoon warming phase. Surface met observation shows comparatively low-pressure in the region for a period of two weeks starting from the last week of April 2003. Increased wind speed and wave height with a clockwise rotation in wind direction and occasional rains are reported during that period. An interesting observation is the cooling of SST in response to the May 2003 cyclone in Bay of Bengal.  Another feature during the warming phase is an oscillation of the order of 14 days observed in SST. Time series observations of salinity in the month of March show the presence of low saline water in the warm pool. A sudden drop of 0.4 psu in surface salinity was observed on 2^nd April, which may be due to the advection of low saline plumes in the warm pool region and/or the local pre-monsoon showers. The onset of southwest monsoon and the associated monsoon currents dissipated the warm pool and thereafter the monsoon conditions with high winds, rough sea and frequent rains prevailed in the region.