A New Climatology of Barrier Layer Thickness and Temperature Inversions in the Bay of Bengal from Argo Data

The Bay of Bengal is a semi-enclosed basin with unique characteristics, largely dominated by the large freshwater flux and semiannual reversing monsoon winds. These large freshwater fluxes are instrumental in driving the formation of barrier layers and temperature inversions in the surface ocean. Barrier layers are formed when the isothermal layer depth (ILD) is greater than the mixed layer depth (MLD). Conversely, surface cooling and strong salinity stratification in the winter drives the formation of temperature inversions. Both barrier layers and temperature inversions can have profound impacts on air-sea fluxes and vertical mixing across the thermocline. In this study, we present a new climatology of barrier thicknesses and temperature inversions for the Bay of Bengal from the last 20 years’ of Argo data. Where possible, we examine the range of interannual variability in these features, and relate them to climatic forcing mechanisms.