Persistence of productive surface thermal fronts in the northeast Arabian Sea

Abstract

In this paper we demonstrate the persistence of sea surface thermal fronts based on the frequency of Sea Surface Temperature gradient satellite data, at seasonal and non-seasonal cycles. Prominent thermal fronts were observed in the northeast Arabian Sea between the 50 m bathymetry contour and continental self break (∼200 metre contour). A total of 45–75% of thermal fronts occurred at the annual time-scales whereas 20–30% occurred at the semi-annual time-scales. Maximum frequency occurrence was observed in the coastal waters south and southwest of Saurashtra peninsula during February and March. Primary productivity co-varies with the frequency of the thermal fronts with a time-lag of 2–4 weeks. This outcome can help on timely and reliable prediction of biologically productive zones.