掩星弯角资料同化在一次暴雨过程中的应用  

Application of GPS bending angle data assimilation in a rainstorm event

作　　者：余江林[1] 寇正[1] 项杰[1] 丁鹏飞[1] 

机构地区：[1]解放军理工大学气象海洋学院,南京211101

出　　处：《暴雨灾害》2014年第2期181-186,共6页Torrential Rain and Disasters

摘　　要：使用GPS掩星弯角资料和NCEP预报场资料,采用GSI(Grid-point Statistical Interpolation)变分同化系统,对同化掩星弯角资料前后的分析场以及数值预报结果进行详细比较,分析了弯角资料同化对2012年7月21日北京特大暴雨预报结果的影响。结果表明,同化掩星弯角资料对初始场中的温度、湿度产生明显影响,500 hPa和700 hPa温度调整中心量值达到0.5℃和-0.6℃,700 hPa湿度调整中心最大量值达-0.14 kg·kg-1;同化过程改变了强降水发生前流场结构,明显提高了强降水中心位置、雨带走向及范围、降水强度的预报准确性;由降水TS评分可知,200 mm以上大暴雨模拟改善效果明显,但对弱降水预报效果较差。Using GPS bending angle and NCEP forecast data , a comparative study was performed to the Beijing rainstorm event on July 21, 2012, with and without assimilation of the bending angle data, based on the GSI three-dimensional assimilation system. The result showed that bending angle data had clear impacts on the temperature and specific humidity fields; the central temperature increment is 0.5 ℃ at 500 hPa and-0.6℃at 700 hPa;the central increment of specific humidity at 700 hPa is-0.14 kg·kg-1. Assimilation of bending angle data changed the stream field and significantly improved the accuracy of the forecast, including the center location of precipitation, rain belt trend and precipitation intensity. According to the threat scores of simulating precipitation, the improvement on the simulation above 200 mm is more evident, but less effective on weak rainfall.

关 键 词：弯角资料 资料同化 暴雨 

分 类 号：P458.121.1[天文地球—大气科学及气象学]