Observed low‐salinity plume off Gulf of Khambhat, India, during post‐monsoon period

Abstract

Freshwater outflow from river systems, joining the northeastern Arabian Sea suggests that the discharge is maximum during summer monsoon and least during other seasons. However, analysis of climatological monthly salinity and ARGO data indicate, low‐saline plumes off Gulf of Khambhat during post‐monsoon, despite the fact that there is no river discharge during this period. It is puzzling to understand the existence of relatively low‐saline waters in the region that warrants further investigation. Simulations from three‐dimensional Princeton Ocean Model (POM) suggest that the opposing winds and the associated onshore coastal currents during July seem to trap the freshwater in the gulf region. As the monsoon withdraws by September, the currents change their direction that would help in releasing the low‐saline waters to open ocean. Winter cooling of the freshwater also enhances the prospects of temperature inversions.