The influence of rainfall upon Scatterometer estimates for sea surface stress: Applications to boundary layer parameterization and drag coefficient models within tropical cyclone environments

The use of satellite scatterometers to probe the winds in and near strong tropical cyclones (TCs) is a valuable tool for both numerical weather prediction (NWP) and weather forecasters. The presence of widespread rain in these storms complicates the estimation of surface winds from the satellite. Improvements in the techniques to infer surface winds from the satellite observations, which remove the effects of rain contamination at the ocean surface, will improve the modeling efforts as they pertain to the prediction of TC intensity. We demonstrate the use of collated and simultaneous high-resolution rain measurements obtained from nearby Next-Generation Radar (NEXRAD) and NASA Quick Scatterometer (QuikSCAT) measurements, respectively. Through the application of the National Oceanic and Atmospheric Administration (NOAA)/Atlantic Oceanographic and Meteorological Laboratories (AOML)/Hurricane Research Division (HRD) TC wind analysis (H*WIND; Powell and Houston [1996] ), we will study the dependence of a surface normalized radar cross-section (NRCS) on the TC wind-speed and rain-rate. The objective is to better observe and understand the dependence of the drag coefficient upon the surface stress across a wide range of conditions and spatial scales within these storms.