The present study documented the formation of surface and subsurface chlorophyll a (Chla) blooms after the passage of tropical cyclone Vardah in the Bay of Bengal, using remote sensing and Bio-Argo float data. Surface Chla bloom occurred in the cyclonic eddy waters and lasted for three weeks, longer than the surface and subsurface Chla blooms in the anti-cyclonic eddy waters (lasted for two weeks). Thickness of the subsurface Chla bloom and depth-integrated Chla increased after the Vardah passage. Analysis shows that Vardah-induced upwelling and vertical mixing transported nutrients to the upper layer and supported the Chla bloom. The fast translation speed and pre-existed anti-cyclonic eddy were the reason of the relatively weak subsurface Chla bloom compared with other studies
