短时强降水诊断物理量敏感性的点对面检验  

Sensitivity Analysis of Short-duration Heavy Rainfall Related Diagnostic Parameters with Point-area Verification

作　　者：田付友[1,2,3] 郑永光 张涛 毛冬艳 唐文苑 周庆亮 孙建华[1,2] 赵思雄[1,2] 

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴重点实验室,北京100029 [2]中国科学院大学,北京100049 [3]国家气象中心,北京100081

出　　处：《应用气象学报》2015年第4期385-396,共12页Journal of Applied Meteorological Science

基　　金：气象关键技术集成与应用项目(CMAGJ2013Z04);公益性行业(气象)科研专项(GYHY201406002;GYHY201206004);国家重点基础研究发展计划(2013CB430106)

摘　　要：对诊断物理量的准确认识可以帮助提高短时强降水的预报准确率,并帮助理解产生短时强降水的可能机制。考虑我国降水观测网的布设特点,结合NCEP最终分析资料的物理量场,以大气水汽总量和最优抬升指数为例,通过点对面检验分析了多个用于表征短时强降水环境特征的诊断物理量的敏感性。结果表明:常规的点对点检验是点对面检验的特殊情况。大气水汽总量和最优抬升指数对短时强降水的指示均存在最佳阈值,且140 km范围内的大气状况才对某点3 h内能否出现短时强降水有直接影响。对于水平分辨率为1°×1°的NCEP资料,建议点对面检验的搜索半径和记录数阈值分别为140 km和2个记录。对多个诊断物理量对比分析显示,短时强降水对水汽相关量最为敏感,其次是表征热力条件的物理量,而表征动力条件和垂直风切变的量的指示意义不够显著。The knowledge about the short-duration heavy rainfall related diagnostic parameters is very important for improving the accuracy,and it can help understand the possible mechanism of meso-scale system producing short-duration heavy rainfall.The data collections of basic datum stations（verification stations）,automatic meteorological observation stations（AMOSs）,and 6-hours NCEP final analysis data（FNL） diagnostic parameters from 2011 to 2012 during 1 June and 31 August are used.By considering characteristics of rain gauge distribution,the total precipitable water and the best lifted index obtained from NCEP FNL are firstly analyzed with the ＂point-area＂ verification method to reveal the sensitivities of short-duration heavy rainfall to the environment conditions.Values of diagnostic parameters for a specific basic datum stations（verification stations） is obtained by adopting bilinear interpolation method.Results show that the popularly used verification is just special cases of ＂point-area＂ verification：One could be reached by setting infinitesimal searching radius,the other can be reached by setting the record threshold infinite.Both the total precipitable water and best lifted index have optimum thresholds indicating short-duration heavy rainfall,and the short-duration heavy rainfall in 3 hours can only be directly affected by the moisture and instability within the radius of 140 km.A searching radius and a record threshold of 140 km and 2 are supposed,respectively,for 1°×1° NCEP dataset.A total precipitable water of 55 mm divides the threat score（T） into monotone increasing and monotone decreasing parts,indicating under-forecast and over-forecast,respectively.A best lifted index of —2℃ divides the threat score into overforecast and under-forecast parts.It is found that the total precipitable water and K index are equal better while both got the same highest threat scores of 0.275 with the bias（B） desirable and the false alarm ratio（F） and the hit rate（H） in the rea

关 键 词：短时强降水 诊断物理量 点对面检验 搜索半径 记录数阈值 

分 类 号：P457.6[天文地球—大气科学及气象学]