Preliminary validation of ocean surface vector winds estimated from China’s HY-2A scatterometer

Abstract

The microwave scatterometer on the Haiyang-2A (HY-2A) satellite is designed to provide global sea surface wind field data. The accuracy of HY-2A scatterometer wind retrievals is determined through various comparisons with moored buoys and the European Centre for Medium Range Weather Forecasting (ECMWF) reanalysis data. These comparisons were made in wide regions, including open sea and coastal areas, over a four-month period from January to March 2012 and August 2012. The retrieved wind speed results agree well with in situ observations and model data with respective biases −0.19 m s⁻¹ and 0.01 m s⁻¹ and root mean square error 2.02 m s⁻¹ and 1.81 m s⁻¹. However, the wind direction errors are a little higher. The overall bias and root mean square deviation of wind direction are −2.24°, 1.74°, and 40.28°, 38.56°, respectively. The wind speed and direction residuals are higher in low- and high-wind speed ranges. In addition, the wind speed and direction are relatively more accurate for open sea than those in coastal regions.

Acknowledgements

The HY-2A wind speed products were obtained from the Chinese National Satellite Ocean Application Service (http://www.nsoas.gov.cn/NSOAS_En/index.html). The buoy wind data were downloaded from the NOAA/NDBC website (www.ndbc.noaa.gov). The ECMWF reanalysis data were downloaded from the ECMWF website (http://apps.ecmwf.int).

Funding

This work was supported by the Chinese Public Science and Technology Research Funds Projects of Ocean under Grant 201005009 and National Natural Science Foundation of China under Grant 41006112.