Evaluation of Sea Surface Winds and Waves Retrieved From the Chinese HY-2B Data

Abstract

The wind and wave derived from the scatterometer and altimeter on board the Chinese Haiyang-2B (HY-2B) satellite were systemically evaluated in this article. The analysis of matchups between advanced scatterometer and the winds from HY-2B scatterometer with wind speeds up to 25 m/s showed a 0.78 m/s root-mean-square error (RMSE) with a 0.97 correlation (COR), superior to the 1.2 m/s RMSE and 0.93 COR of winds from the altimeter of HY-2B. Simultaneously, significant wave heights (SWHs) measured from HY-2B were collocated with measurements from the Jason-3 altimeter. Analysis of the calibration concluded that the observations from the HY-2B altimeter performed well at low-to-moderate sea states, yielding an RMSE of 0.29 m for SWH with a 0.98 COR for geophysical data records (GDRs) data after systematic corrections using the MOE determination method. In particular there were 20 typhoons occurring in China Seas during 2019–2020. The evaluation of high SWH when compared with those (SWH > 7 m) from Jason-3/WW3 indicated that HY-2B is accurate, with a 0.87 m/0.68 m RMSE and a 0.85 COR with SWH. Finally, statistical analysis of wind speed and SWH was investigated through waves simulated from the WAVEWATCH-III (WW3)/hybrid coordinate ocean using the current and the sea surface temperature (SST). The HY-2B wind measurements performed well at sea surface currents below 1 m/s and SWH less than 3 m, while a term for SST should be included in the scatterometer wind speed retrieval. In addition, wave states likely affect the accuracy of HY-2B wave speed measurements.