多种空间检验方法在不同分辨率模式降水预报评估中的应用  

Application of multiple spatial verification methods to precipitation forecasts from different resolution models

作　　者：俞碧玉 朱科锋[2,3] YU Biyu;ZHU Kefeng(Meteorological Center of East China Regional Air Traffic Management Bureau of Civil Aviation,Shanghai 200335,China;State Key Laboratory of Severe Weather and Joint Center for Atmospheric Radar Research of CMA/NJU,School of Atmospheric Sciences,Nanjing University,Nanjing 210023,China;Key Laboratory of Transportation Meteorology of China Meteorological Administration,Nanjing Joint Institute for Atmospheric Sciences,Nanjing 210041,China)

机构地区：[1]民航华东空管局气象中心,上海200335 [2]南京大学,中尺度灾害性天气教育部重点实验室/大气科学学院,南京210023 [3]南京气象科技创新研究院中国气象局交通气象重点开放实验室,南京210041

出　　处：《气象科学》2022年第3期341-355,共15页Journal of the Meteorological Sciences

基　　金：国家重点研发计划项目(2018YFC1507604);国家自然科学基金资助项目(41975124)。

摘　　要：利用单一的客观评估方法并不能有效揭示预报误差来源。利用逐小时5 km格点融合降水产品,本研究使用了多种客观评估方法综合评估了南京大学2016年夏季汛期试验4 km与12 km WRF模式。整体上,两种分辨率都能成功地预报主雨带,4 km WRF在午后对流及复杂地形预报上更优。比较了各类客观评估方法,邻域法显示4 km WRF预报准确性更高,但对于强降水(≥13 mm·(6 h)^(-1)),两种模式预报的空间误差都较大。尺度分离法显示,对于小尺度系统,4 km WRF能较好再现对流但存在较大位置误差,而12 km WRF则漏报。MODE法(Method for Object-based Diagnostic Evaluation)显示4 km WRF在对象强度预报上更接近观测,但强度和范围偏大,导致华南偏强,而范围偏小造成江淮偏弱,12 km WRF低估主要是漏报。不同评估方法能清晰展示4 km WRF和12 km WRF预报误差的差异,为后续模式改进提供了重要参考。A single objective evaluation method can not effectively reveal the source of forecast error.In this study,several objective evaluation methods were used to evaluate the precipitation forecasts of 4 km and 12 km WRF model running real-time at Nanjing University during summer period of 2016.The 5 km hourly gridded merged precipitation products were used as observation.In general,both 4 km and 12 km WRF model can successfully reproduce the main rainband.4 km WRF performs better than 12 km WRF in the prediction of the afternoon convection and precipitation over complex terrain area.Results from different objective evaluation methods are compared.The neighborhood method shows that for light rains,4 km WRF can maintain useful skill score up to smaller scales.But for heavy rains(≥13 mm·(6 h)^(-1)),the spatial errors of the two models are both large.The scale separation method shows that the 4 km WRF can reproduce the small-scale systems well but still has clear position errors.On the contrary,12 km WRF just missed the small-scale convection.The Method for Object-based Diagnostic Evaluation(MODE)shows that the rainfall intensity forecasts of 4 km WRF are much closer to the observation than 12 km WRF.However,in South China,it overestimates the intensity and coverage area of the objects resulting the overestimation of precipitation amount in that region.In the Yangtze-Huaihe River,it underestimates the coverage area resulting the underestimation of precipitation amount in that region.On the contrary,the forecast bias of 12 km WRF is due to the failure in the prediction of the small-scale systems.Different evaluation methods can clearly show the difference of prediction errors between 4 km WRF and 12 km WRF,which provides an important reference for the subsequent model improvement.

关 键 词：对流可分辨模式 午后对流 降水日变化 邻域法 尺度分离法 MODE方法 

分 类 号：P457.6[天文地球—大气科学及气象学]