利用探空资料、地基GPS/MET水汽监测资料,对恩施、宜昌、武汉三站地基GPS反演大气可降水量(GPS Precipitable Water Vapor,GPS/PWV)与探空进行了对比,表明GPS/PWV与探空RS/PWV具有良好的一致性。湖北省17站3 a GPS/PWV资料分析表明,GPS/PWV具有明显的月变化及日变化特征,分布具有从南往北逐渐递减,从西至东逐渐增加的特点。强降水个例分析表明GPS/PWV峰值略早于降水以及雷达回波峰值出现时间,高时空分辨率的GPS/PWV配合雷达对天气形势的分析以及降水的判断有一定的指导作用。
Various types of radars with different horizontal and vertical detection ranges are deployed in China, particularly over complex terrain where radar blind zones are common. In this study, a new variational method is developed to correct threedimensional radar reflectivity data based on hourly ground precipitation observations. The aim of this method is to improve the quality of observations of various types of radar and effectively assimilate operational Doppler radar observations. A mudslide-inducing local rainstorm is simulated by the WRF model with assimilation of radar reflectivity and radial velocity data using LAPS(Local Analysis and Prediction System). Experiments with different radar data assimilated by LAPS are performed. It is found that when radar reflectivity data are corrected using this variational method and assimilated by LAPS,the atmospheric conditions and cloud physics processes are reasonably described. The temporal evolution of radar reflectivity corrected by the variational method corresponds well to observed rainfall. It can better describe the cloud water distribution over the rainfall area and improve the cloud water analysis results over the central rainfall region. The LAPS cloud analysis system can update cloud microphysical variables and represent the hydrometeors associated with strong convective activities over the rainfall area well. Model performance is improved and the simulation of the dynamical processes and moisture transport is more consistent with observation.
