Wind-Wave Relationship Model and Analysis of Typhoon Wave Fields in the South China Sea From HY-2A Satellite Observations

Significant wave height is an important parameter for characterizing ocean surface waves. With the development of remote sensing technology, satellite radar altimetry has become an essential tool for obtaining significant wave height estimations. However, its measurement only covers the satellite track on the ground and cannot be applied to large regions or areas. In this study, we obtained significant wave height from the Hai Yang-2A (HY-2A) radar altimeter and sea surface wind speed at a 10-m height from the HY-2A microwave scatterometer for October 2013, and then proposed a wind-wave relationship model for the South China Sea using linear/nonlinear regression analysis at high/low wind speeds (0-40 m s(-1)). By comparison with two other wind-wave models and validation with HY-2A observations in November 2013, our results show that the proposed wind-wave relationship model is credible, and at low wind speed exhibited good consistency with the wind-wave model from in situ observations. According to the proposed model, significant wave height from the HY-2A microwave scatterometer-retrieved wind speed and ocean wind wave analysis during the "1329" Typhoon Krosa were successfully obtained and determined. Data coverage of the computed significant wave height was far wider than that of the satellite radar altimeter observations and demonstrated development of typhoon wave fields over a large region. Overall, this study and proposed model provide useful information for the analysis and forecast of typhoon waves and potential storm surge disasters.