Extended Abstract (32K)14A.6
Evaluation of SeaWinds wind speed measurements in hurricane Floyd
W. Linwood Jones, University of Central Florida, Orlando, FL; and J. D. Park, I. Adams, and S. S. Chen
The SeaWinds scatterometer on the QuikSCAT satellite obtained good quality ocean surface wind speed measurements in hurricane Floyd during 1999. This research is the result of a special purpose tropical cyclone wind speed retrieval algorithm. This algorithm improves over the standard L2B wind vector science product by using; (1) higher spatial resolution 12.5 km binned sigma-0 slices, (2) improved rain flagging using the QRad rain rates, and (3) a special hurricane geophysical model function. Details of the algorithm are discussed and results are presented for several passes over hurricane Floyd where there were near-simultaneous measurements by the NOAA Hurricane Research Division's P-3 aircraft.
SeaWinds retrieved wind speeds and QRad rain rates are compared with high temporal and spatial resolution hurricane numerical model (PSU/NCAR MM5) simulations. Geophysical validation of our retrieved wind speeds is established using these numerical model calculations as "surface truth". These case studies show that the combination of QRad rain rates, to identify regions contaminated by strong rain, and improved resolution slice sigma-0's results in significant improvements when using our retrieval algorithm. By excluding regions of heavy rain, we can eliminate large wind speed errors associated with rain attenuation and the improved spatial resolution enables useful measurements between the hurricane spiral rain bands. Also comparisons are made with the QuikSCAT L2B standard 25 km wind vector retrievals and differences between the wind speed retrievals are explored.
Session 14A, Tropical Cyclone Observations and Structure III (Parallel with Sessions 14B, 14C, and 14D)
Thursday, 2 May 2002, 2:00 PM-3:30 PM
Previous paper