A multi-sensor study of conditions leading to the formation of a cyclone over the Arabian Sea during 5-9 May 2004

The present study investigates the conditions leading to the formation of a cyclone over the Arabian Sea using in situ, buoy, Argo floats, island, satellite, reanalysis and blended datasets. Cyclogenesis parameters, such as the sea-surface temperature (SST), the mid-tropospheric relative humidity (MTRH), the relative vorticity (RV) and the vertical wind shear (VWS), were examined. Furthermore, the variability of different parameters from satellite data, such as the SST, the outgoing longwave radiation (OLR), the precipitable water (PW), the rainfall rate and wind speed (WS), were also investigated from the pre-disturbance stage to the cyclonic stage. An analysis of the dynamic and thermodynamic cyclogenesis parameters from the reanalysis data showed that the MTRH, RV and PW increased dramatically from the pre-disturbance stage to the depression stage by 150%, 530% and 32%, respectively. It is envisaged that better spatial and temporal satellite estimates of the OLR, SST, PW, blended Objectively Analyzed air-sea Flux (OAFlux) project, European Centre for Medium Range Weather Forecast (ECMWF) data products and new tools, such as moored buoys and Argo floats, would be useful for the study of cyclones over the Arabian Sea.