Cyclonic intensity study using sea level pressure estimations from Ocensat-II scatterometer winds over Bay of Bengal during 2013

Abstract. Sea level pressure (SLP) fields prevailing over Bay of Bengal (BoB) during Phailin, Lehar and Madi cyclones (2013) were estimated using University of Washington Planetary Boundary Layer (UWPBL) model with Oceansat-II Scatterometer (OSCAT) sea surface winds as an input parameter. Model performance in estimating SLP variations during cyclonic periods was investigated by comparison against cyclone reports of Indian Meteorological Department (IMD) and in-situ measurements. Pressure drop as per IMD reports were observed to be higher than model estimates, primarily due to limitations in scatterometer wind data. However, model retrieved pressure fields compare well against buoy measurements, with a bias of 0.0042, −0.1279 and −0.4406 observed for Phailin, Lehar and Madi cyclones respectively. The contrast in pressure drops between model estimates and IMD reports was investigated by comparing scatterometer winds against IMD reported maximum sustainable winds.