雷达降水资料一维变分同化研究——湿度廓线调整  

One-Dimensional Variational Assimilation of Radar-Derived Precipitation Data: Retrieving of Humidity Profiles

作　　者：王叶红[1] 崔春光[1] 赵玉春[2] 

机构地区：[1]中国气象局武汉暴雨研究所 [2]武汉中心气象台,武汉430074

出　　处：《气象科技》2004年第5期322-328,共7页Meteorological Science and Technology

基　　金：国家重点基础研究发展规划"973"项目(G1998040910);"十五"国家重点科技攻关计划项目"中国气象数值预报技术创新研究"(2001BA607B);湖北省自然科学基金项目(2003ABA009)共同资助

摘　　要：采用η坐标中尺度有限区域模式进行了数字化天气雷达探测降水资料的一维变分(1DVAR)同化试验,结果表明充分利用高时空分辨率的雷达降水资料所包含的丰富的中尺度信息,调整湿度廓线,从而改善模式初始湿度场,能有效提高模式暴雨预报能力。“98·7”鄂东沿江特大暴雨的数值试验结果表明,应用1DVAR方法同化1h雷达降水资料调整模式湿度廓线后,极大地缩小了分析降水与观测降水间的差距,而且24h预报能模拟出与实际降水发生区域相对应的位于鄂东的大暴雨区,而变分前模式预报效果不佳。进一步的分析表明,应用雷达降水资料对短时预报(0～12h)的改进更为显著,而对12h之后降水预报的改善则不明显。With the limited area mesoscale numerical model under η coordinate, one dimensional variational assimilation experiments of precipitation derived from digital weather radar were conducted. Results indicate that the retrieved humidity profiles and the improved initial humidity field can efficiently increase the capability of forecasting severe rainfall by fully using adequate mesoscale information contained in high temporal spatial resolution radar derived rainfall data. The numerical modeling experiment of the torrential rainfall occurred along Yangtze River in the east of Hubei in July 1998 was conducted. Results show that model retrieved humidity profiles using the 1 hour radar derived precipitation assimilated with 1DVAR method greatly reduce the errors in precipitation analysis; moreover, the torrential rainfall in the east of Hubei was well simulated in the 24 hour prediction while the model performed not well without variational assimilation. Further analyses shows that the improvement of short range forecasting (1-12 hours) was more remarkably than that of 12 hour prediction when the radar derived rainfall data was assimilated into the numerical model with the 1DVAR method.

关 键 词：降水资料 变分同化 廓线 中尺度 大暴雨 预报效果 降水预报 湿度 发生区域 利用 

分 类 号：P457[天文地球—大气科学及气象学] P458