风浪谱模型在高度计风速反演中的应用

依据粗糙海面电磁波镜面散射理论,将根据全波数范围内的风浪谱模型计算的标准化雷达后向散射截面与T/P卫星高度计测得的雷达后向散射截面(Ku波段)进行比较,实现了对高度计风速的反演.研究表明,在所选浮标附近海域,波龄因子对高度计风速反演存在较大影响.与目前高度计业务化算法相比,考虑波龄因子影响后,根据谱模型反演获得的风速与中国近海浮标风速之间均方根误差和平均偏差更小.由于波龄因子可以根据高度计测得有效波高以及业务化算法获得的风速得到,因此根据风浪谱模型反演获得的风速具有广泛的适用性.

Application of wind wave spectrum model in altimeter wind speed retrieval

Based on the specular reflection theory of electromagnetic waves at rough sea surface and the spectral model of wind waves with a wave age factor, the sea surface wind speeds were retrieved from the normalized radar backscatter cross section measured by TOPEX/Poseidon Ku-band altimeter using the mean square slope calculated from the spectral models of the wind waves and the gravity-capillary waves. The study showed that the wave age factor has a significant influence on retrieving altimeter wind speeds. Compared with the empirical algorithms in operational use for altimeter winds retrieval, after considering the effects of wave age factor, both the bias and the root mean square error between wind speeds retrieved by the proposed analytical algorithm and buoy measured wind speeds in Eastern China Sea decrease significantly. The relationship between the wave age and non-dimensional wave height can be used to calculate the wave age factor based on altimeter measured significant wave height and wind speeds. Thus, the algorithm proposed in this study has a comprehensive applicability.