Investigation of Ocean Sub-Surface Processes in Tropical Cyclone Phailin Using a Coupled Modeling Framework: Sensitivity to Ocean Conditions

The present study is aimed to investigate sub-surface ocean processes and their contribution the intensification of a tropical cyclone (TC) from coupled-modeling perspective. Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) model was employed simulate TC Phailin, which originated over Bay Bengal made landfall on eastern coast India in October 2013. Three condition datasets—viz., (a) European Centre for Medium-Range Weather Forecast (ECMWF) Ocean Reanalysis, (b) Climate System Version 2 (CFSV2) Operational Analysis, (c) Hybrid Coordinate Model (HYCOM) Reanalysis datasets—were used initial boundary conditions oceanic component coupled three different simulations Phailin. All showed delay compared observation, ECMWF simulated most intensified TC. CFSV2 deeper mixed layer (ML) higher mixing, hindered intensification. Furthermore, entrainment cold water ML led reaching surface and, consequently, decreased sea temperature, acted as negative feedback storm cases HYCOM. realistically interactions with cold-core eddy before landfall. A sudden increase heat content, addition due entrainment, prevention were indicative breaking barrier (BL) ECMWF, further corroborated by spatial distribution BL thickness simulation. This positive findings this strongly suggest that not only incorporation physical modeling TCs but also proper representation prevailing mesoscale features salinity, current profiles datasets essential realistic TCs.