卫星高度计波高数据同化对西北太平洋海浪数值预报的影响评估

Validation of impact of assimilation of altimeter satellite significant wave height on wave forecast in the northwest Pacific

通过数值试验验证卫星高度计波高数据同化对西北太平洋3 d海浪预报的改进效果。驱动海浪模式的强迫场采用国家海洋环境预报中心基于MM5模式预报的风场,波高数据同化使用的观测数据是Jason-1卫星高度计有效波高。用最优插值数据同化方法获得海浪有效波高的最优估计并重构相应的海浪方向谱,以此为初始场进行为期3 d的数值预报试验。与没有同化的预报进行了比较和分析,结果表明卫星高度计海浪数据同化对072 h预报有不同程度的明显改善,改进程度随预报时效的增加而减少。

A detailed numerical study was performed to validate the impact of assimilation on three days＇wave forecast in the northwest Pacific.The MM5 wind field predicted in NMEFC（National Marine Environment Forecast Center） was used to drive the wave model and altimeter satellite significant wave height provided by Jason-1 satellite were assimilated in the wave model.The optimal interpolation method was used in our assimilation to acquire the optimal analysis of significant wave height and corresponding wave directional spectra.Three days＇wave forecast with and without assimilated initial field were computed and the results were compared.The statistical analysis show a considerable improvement in 0～72 h wave forecasting while the improvement goes less sensitive as the forecasting time grows.