中文摘要：

本文采用美国国家大气研究中心（NCAR）开发的中尺度数值模式WRFV3.7及其三维变分同化系统WRF-3DVAR对2008年飓风＂艾克＂进行了数值模拟研究。利用多普勒天气雷达观测资料具有高时空分辨率的优点,将美国两部多普勒天气雷达资料进行速度退模糊等必要质量控制后同化进中尺度数值模式,考察雷达资料同化对飓风＂艾克＂预报的改进程度。试验结果表明：将雷达资料用于对流尺度分辨率下飓风初始化需要对变分同化系统中特征尺度化因子进行优化调整,使观测资料能够以较为合理的方式调整模式初始场并进而改进预报;雷达径向风同化可以有效调整模式初始场中的飓风动力和热力结构,而经过尺度化因子调整后的雷达径向风同化则在飓风观测中心位置产生较为合理的气旋性风场增量,提供更为确切的中小尺度信息,使模式初始场更加接近观测并进而改进对飓风路径和强度的预报。

英文摘要：

The impacts of assimilation of radial velocity（Vr）data for the application of analyses and forecasts for Hurricane Ike（2008）are investigated using the framework of Weather Research and Forecasting（WRF）V3.7and its three-dimensional variational data（3DVAR）assimilation system developed by the U.S.National Center for Atmospheric Research（NCAR）.To evaluate the impact of using the high spatial and temporal resolution of the radar data on the forecast of Hurricane Ike,Vrobservations from two coastal radars are pre-processed with quality control procedures before they are assimilated using 3DVAR.Results show that,it is necessary to tune the background error length scale factor to better spread out observations for hurricane radar data assimilations.It is found that Vrdata are able to adjust the hurricanes thermal and dynamic structure significantly.With smaller length scale factor,a much clearer cyclonic circulation wind increment around the observed hurricane center can be observed,providing effective meso-and micro scale information for the analysis,which can further improve the hurricane track and intensity forecast.