Improvements in QuikSCAT Near-Real Time Wind Processing Implemented at NOAA/NESDIS
Zorana Jelenak and Paul S. Chang Zorana.Jelenak@noaa.gov
Center for Satellite Applications and Research NOAA/NESDIS 5200 Auth Road, Camp Springs, MD 20746, USA
Michael Brennan NOAA/NWS/NCEP/National Hurricane Center/UCAR
NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) in cooperation with NASA/JPL has been providing near-real time (NRT) QuikSCAT ocean surface wind vector products at resolutions of 25 km and 12.5 km to the operational community since early 2000. Remotely-sensed ocean surface wind vector (OSWV) data from QuikSCAT have also become an important tool for analysis and forecasting at the National Hurricane Center (NHC), Central Pacific Hurricane Center (CPHC), NWS WFO Guam, and the U.S. Navy’s Joint Typhoon Warning Center (JTWC). QuikSCAT wind speed and direction retrievals are utilized by NHC in the analysis and forecasting of tropical cyclones (TCs) in the North Atlantic and eastern North Pacific basins. The data are also used by NHC’s Tropical Analysis and Forecast Branch (TAFB) in the issuance of marine forecasts, warnings, and analyses for large portions of the tropical North Atlantic and eastern Pacific oceans.
QuikSCAT data have had a major impact in TC analysis and forecasting by providing information on TC wind radii, maximum wind speed in tropical storms and marginal hurricanes, and TC center identification and location. However, this experience with QuikSCAT wind retrievals has also revealed limitations, such as larger retrieval uncertainties at the swath edges, over-flagging of retrievals as rain contaminated, and under estimation of high wind speeds. To address these shortcomings in the NRT QuikSCAT retrievals, JPL implemented several changes in the science level QuikSCAT processing system. These changes have also been adapted to NRT processing system, which has been running in a parallel test mode since May 2006. The NRT QuikSCAT processing improvements were validated by examining six months of wind retrievals from 2003 processed with both the current and the parallel algorithms. Validation was conducted by the Ocean Surface Winds Team in STAR, with evaluation from the operational forecaster perspective being conducted by colleagues at NHC and the Ocean Prediction Center (OPC). Results of the validation analyses show that the retrievals from the new processing perform better than those from the current processing and that this new algorithm should be implemented in operations.
The changes in NOAA/NESDIS QuikSCAT NRT processing of wind data will be explained and improvements in new data product will be discussed.