Sensitivity of the Arabian Sea mixed layer to 1994-1995 operational wind products

The evolution of the upper ocean in the strong seasonally forced Arabian Se a, as observed by a mooring deployed in 1994-1995, is investigated using th e Naval Research Laboratory Layered Ocean Model (NLOM). Model simulations w ere sensitive to the choice of surface wind products used for forcing, and results are reported for simulations forced by monthly mean climatologies a nd 12 hourly 1994-1995 wind products from two operational atmospheric forec ast models, the European Centre for Medium-Range Weather Forecast model and the Navy Operational Global Atmospheric Prediction System model of Fleet N umerical Meteorology and Oceanography Center (FNMOC). The NLOM yields the b est prediction of sea surface temperature (SST) and mixed layer depth when using FNMOC forcing. Surface cooling is found to be responsible for the sea sonal SST minimum during the NE monsoon. Heat advection is found to be impo rtant for supporting the surface cooling during the second half of the NE m onsoon. Strong entrainment and appreciable advective cooling are responsibl e for the SST minimum of the SW monsoon. The NLOM wind experiments strongly suggest that thermal convection may be important in the central Arabian Se a during the winter months.