On the upper ocean response to tropical cyclones: Satellite microwave observation

In this study we report results of investigation of response of the upper ocean to passage of three tropical cyclones - Ignacio, Jimena and Kilo, which simultaneously travel over the central and eastern parts of the Pacific Ocean in late August-early September 2015. Wind fields for these TCs were derived from synergy of three microwave radiometers - ESA Soil Moisture and Ocean Salinity (SMOS), NASA Soil Moisture Active Passive (SMAP) and JAXA Advanced Microwave Scanning Radiometer 2 (AMSR-2). As the SST field we used the satellite product of the daily average sea surface temperature MW OISST resulting from optimal interpolation of data from various microwave radiometers. The satellite observations were supplemented with the Best Track data, and characteristics of the ocean vertical stratification available from WORLD OCEAN ATLAS 2013 version 2. SST anomalies generated by each of the TCs are detected as difference of the successive daily averaged SST field. Characteristics of the SST and sea level anomalies, - magnitude of depressions, their width, shift from the TC track, are then analyzed as a function of TC parameters (maximal wind speed and its radius, translation velocity) and environmental conditions, - local latitude of TC location and the background ocean stratification below TC. Empirical dependencies of characteristics of SST and the sea level anomalies on TC parameters and environmental conditions are established and parameterized.