光流法在强降水过程预报检验中的应用  

Application of Optical Flow Method to Heavy Precipitation Forecast Verification

作　　者：朱智慧 黄宁立 陈义 

机构地区：[1]上海海洋气象台,上海201306

出　　处：《气象科技》2016年第4期596-604,611,共10页Meteorological Science and Technology

基　　金：上海市气象局面上项目(MS201409);上海市气象局研究型项目(YJ201501)资助;中国气象局预报员专项项目(CMAYBY2013-023);上海市科委课题(14231202400)

摘　　要：光流法是运动图像分析的重要方法,主要用于确定目标的运动信息。数值模式产生的格点化的要素预报场,也是一种图像,应用于图像分析的光流法可以用到数值模式检验领域。本文在数值模式强降水过程预报检验领域引入了光流检验方法,首先利用理论模拟对光流检验方法的原理进行了阐述,然后通过对3种不同类型强降水过程中ECMWF和T639模式的24h降水预报进行检验,分析了光流检验方法在强降水过程预报检验中的实际应用。结果表明:1利用光流检验方法可以将数值模式的预报误差分解为强度、位移和角度3种误差场,从而实现对数值模式强降水预报误差的精确量化分析。2通过对梅雨锋、西南涡、台风等3种不同类型强降水过程进行光流检验方法的应用,可以发现,不同数值模式对同一次降水过程的预报在强度、位移、角度误差方面一般表现不同,光流检验结果在反映不同模式对降水预报的强弱、雨带偏移的角度和距离差异方面具有较高的参考价值。The optical flow method is an important method in motion image analysis,which is mainly used to determine the motion information of a target.The element forecast fields produced by numerical models are gridded spaces,which are also a kind of images,and the optical flow method used in image analysis can be applied to the numerical model verification.The optical flow method is used to the heavy precipitation forecast verification.The principles of the optical flow method are described by using the theoretical simulation,and then through the verification on the 24 hprecipitation forecast of ECMWF and T639 models for three different types of heavy precipitation process,the practical application of the optical flow verification method in heavy precipitation forecast verification is discussed.The results show：（1）By decomposing the forecast error into intensity,displacement,and angular errors,the optical flow verification method can give an accurate quantitative analysis of the heavy precipitation forecast errors.（2）Based on the application of the optical flow verification method for three different types of heavy precipitation processes such as plum rain,southwest vortex,and typhoon,it can be found that for the same precipitation process,different numerical models usually have different performance in strength,displacement,and angular errors.The optical flow verification results have high reference value in reflecting the differences of the precipitation strength,precipitation belt deviation angle,and distance of different models.

关 键 词：光流法 强降水过程 预报检验 

分 类 号：P458.121[天文地球—大气科学及气象学]