Seawinds Improved Ocean Vector Wind Retrievals in Hurricanes

The most pressing issue for the Ku-band scatterometer is associated with the measurement of ocean surface winds in tropical cyclones in the presence of precipitation, which can significantly degrade the wind vector retrieval. Furthermore, at high wind speeds (> 32 m/s), the measurements suffer from radar backscatter saturation effects. Since the spatial resolution of satellite scatterometer and associated ocean vector winds (OVW) retrieval algorithms have been specifically developed for global synoptic-scale wind measurements, scatterometers have failed to estimate the peak winds in tropical cyclones. Previously, the Central Florida Remote Sensing Laboratory (CFRSL) developed a special hurricane retrieval algorithm that uses a novel active/passive scatterometer retrieval algorithm designed specifically for extreme wind events, known as QuikSCAT hurricane wind vector retrieval (Q-Winds). To assess the performance of the algorithm, the retrieval results were compared to an independent “surface truth”. The National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division (HRD) H*Wind surface wind analyses (Powell, 1998), derived from near-simultaneous in-situ and remote sensor measurements of the hurricane surface winds from NOAA and U.S. Air Force Weather Squadron aircraft, were used to validate the Q-Winds retrieval. Recently, under the Joint Hurricane Testbed (JHT) project, the Q-Winds product has been extended to near real-time (NRT) application. In this new approach, existing software utilities are implemented to transform the Q-Winds vector wind output to existing NRT QuikSCAT data products in the Binary Universal Form for the Representation of meteorological data (BUFR) format, Merged Geophysical Data Record (MGDR)