Using Surface Pressure to Validate Tropical Cyclone Surface Wind Retrievals From SAR

The overall goal of this research is to improve the accuracy and usefulness of wind retrievals from synthetic aperture radar (SAR) imagery of the sea surface under and near the centers of tropical cyclones (TCs). SAR provides unique high resolution (even sub-km-scale) imagery of the ocean surface roughness underneath TCs. However, the standard methods for interpreting this information in terms of surface wind were all developed using data from conditions far from the extremes of the TC environment and have proven to be lacking in this regime. We propose a new validation method using sea-level pressure fields calculated from the SAR measurements with a planetary boundary layer (PBL) model. The reason for using surface pressure measurements is that they are comparatively much more reliable than wind measurements in extreme wind conditions. Our research leverages our previous and continuing efforts in sea-level pressure (SLP) retrieval from satellite ocean vector winds, theoretical boundary layer model development, and the analysis of organized coherent structures in tropical cyclone boundary layers.