Influence of Surface Wind Variability on Intense Tropical Oceanic Precipitation

Abstract:

The influence of synoptic and mesoscale sea surface wind features on heavy rainfall remains unclear due to the lack of observations over the oceans. In this study, satellite-based scatterometer wind retrievals are coupled with atmospheric reanalyses to reveal oceanic surface wind properties, and investigate the impact of air-sea exchanges of water and energy surrounding rainfall. Three-hourly precipitation data from NOAA’s CMORPH are used to identify the most intense precipitation features, and composites of surrounding meteorological fields are examined to understand the forcings encouraging localized heavy rainfall. Atmosphere-ocean surface heat and moisture fluxes are analyzed with corresponding meteorological fields provided by MERRA reanalyses. Surface wind patterns surrounding the precipitation systems are provided by ASCAT, and differences between MERRA and scatterometer near surface winds are considered. This study aims to understand the co-evolution of surface wind kinematic features, intense oceanic tropical rainfall, and the storm environments corresponding with such events.