Formation mechanisms of temperature inversions in the southeastern Arabian Sea

Numerical simulations using a high resolution (0.25 degrees x 0.25 degrees, 40 levels) OGCM of the Indian Ocean are used to study the formation mechanisms of temperature inversions (TI) in the southeastern Arabian Sea ( SEAS) during winter. To the west and south of India, haline stratification is a necessary pre-requisite for TI formation. Off the southern tip of India, low-salinity water advected from the Bay of Bengal is cooled by strong winds and leads to TI formation. In the southern part of the SEAS, advection of this cooler low-salinity water over warm salty SEAS water leads to the formation of TI and occur at a deeper depth ( similar to 80 m) due to the downwelling within the Lakshadweep High. In the northern part, TI occur at a much shallower depth ( similar to 20 m) and are caused by shortwave radiation penetrating below the mixed layer of about 12 m.