SEAWINDS IMPROVED OCEAN VECTOR WIND RETRIEVALS IN HURRICANES

QuikSCAT has recently passed its tenth anniversary of serving science community with valuable global wind vectors measurements under all weather conditions. The near real-time (NRT) QuikSCAT wind data processing, at the National Oceanic and Atmospheric Agency (NOAA), provides wind retrievals along with ocean radar backscatter in 25 and 12.5 km resolution on an orbit-by-orbit basis within three hours of observation. Throughout the Calibration/Validation period, QuikSCAT data have been provided to the science working team to assess its quality. Simultaneously, the data have been provided to NOAA to test the near real-time processing and dissemination system, and to perform in-house quality control evaluations of the data.

This paper presents a new NRT hurricane ocean vector wind (OVW) product produced from the SeaWinds scatterometer active/passive measurements on QuikSCAT using a unique OVW retrieval algorithm tailor-made for hurricane applications. This new algorithm is based on inverting the NRT SeaWinds data using a special geophysical model function (GMF) developed for extreme wind events.

This GMF utilizes the simultaneous passive measurements provided in the NRT data to correct active ocean backscatter for rain attenuation and rain volume backscatter effects. The new hurricane wind-force retrieval also incorporates a unique ambiguity selection algorithm guided by the counter-clockwise rotation of the storm (in northern hemisphere). Results for several recent storms are presented and the statistical comparisons with level 2 data (L2A & L2B) products are also provided.