南京地区降水预报研究  

Research on precipitation forecasts in Nanjing City

作　　者：万夫敬[1] 袁慧玲[1] 宋金杰[1] 王元[1] 

机构地区：[1]南京大学大气科学学院与中尺度灾害性天气教育部重点实验室,南京210093

出　　处：《南京大学学报（自然科学版）》2012年第4期513-525,共13页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(40830958;41175087);中央高校基本科研业务费专项资金(020714340003);气象行业专项(GYHY200906011;GYHY200906014-01-01;GYHY201206005);南京大学人才引进科研启动经费(020722631003);江苏高校优势学科建设工程资助项目

摘　　要：南京地区地处东亚季风影响下的长江下游地区,又是梅雨锋暴雨的成灾区,以南京地区为例研究长江下游地区的降水特征,具有重要的典型性和示范性.利用南京市2004-2006年5-9月T213模式数值预报场资料和同期降水观测资料,使用模式输出统计(model output statistics,MOS)预报方法,借助逐步回归和logistic回归等统计工具,研究了南京地区的降水事件,并将logistic回归预报结果与事件概率回归(REEP)方法作了比较.结果表明,logistic回归方法在降水概率预报方面比事件概率回归有明显优势.为了改善降水预报效果,使用当地降水发生的频率作为新的阈值,称为优化阈值,将它作为判断概率预报有无降水的标准.同时,对入选降水方程的预报因子进行分析,提出了南京地区汛期降水的热动力概念模型.Rainfall is one of the primary forecasted factors,and it has significant importance to predict precisely and timely ,which can greatly reduce its damage. Nanjing locates in the East Asian monsoon region and the lower reaches of Yangtze River, which can represent the main precipitation features in this area. In this paper, precipitation probability forecasts （PPF） are generated for 24 h summer rainfall in Nanjing through stepwise regression and logistic regression methods. The regression equation uses the operational T213 products and observed rainfall data in Nanjing station during 2004-- 2006. The results from the logistic regression method are much better than that using regression estimation of event probability （REEP）. In order to further improve PPF, optimal threshold has been applied to discriminate rain and no-rain events, depending on sample climatological frequency in Nanjing. A conceptual rainfall model has been established for Nanjing station, based on thermodynamic and statistical relationship among the selected predictors in the regression equation.

关 键 词：降水动力模型 降水概率预报 LOGISTIC回归 

分 类 号：P457.6[天文地球—大气科学及气象学]