NCEP CFSv2模式对中国西南月尺度降水预测能力评估  

Evaluation of NCEP CFSv2 on Monthly Precipitation Prediction in Southwest China

作　　者：吴遥 唐红玉[1] 蒋兴文[2] 向波 WU Yao;TANG Hongyu;JIANG Xingwen;XIANG Bo(CMA Key Open Laboratory of Transforming Climate Resources to Economy/Chongqing Climate Centre,Chongqing 401147,China;Institute of Plateau Meteorology,CMA,Chengdu/Heavy Rain and Drought-Flood Disaster in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China)

机构地区：[1]中国气象局气候资源经济转化重点开放实验室/重庆市气候中心,重庆401147 [2]中国气象局成都高原气象研究所/高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072

出　　处：《高原山地气象研究》2024年第3期67-75,共9页Plateau and Mountain Meteorology Research

基　　金：中国气象局数值预报国省统筹研发2023年度气候模式解释应用项目;重庆市气象局业务技术攻关项目(YWJSGG-202208);重庆市气象部门人才支持性项目(RCZC-202303)。

摘　　要：基于NCEP CFSv2模式逐日预测未来45 d的降水数据,结合站点观测资料,对西南地区逐月降水量空间形态和年际变化预测技巧进行评估。结果表明:模式除汛期(5—9月)在四川东北部和重庆东北部为干偏差外,其余地区和月份均为湿偏差。偏差较大的月份主要集中在夏季,区域平均偏差从1—12月呈现出“上升—下降—上升”的趋势,4月最大,10月最小。随着预报时效的增加,模式对空间形态预测技巧降低,但对量级预测技巧提升。在不同预报时效上,模式对中雨、大雨和暴雨日数的逐月“Ω”趋势预测基本正确,但小雨日与观测呈现相反特征。模式对小雨和中雨日的预测高于观测,但大雨和暴雨日低于观测。年际变化上,模式在大多数地区预测为正相关,负相关区主要集中在四川盆地至川西高原地区,以及重庆、四川和贵州三省交界地区。高相关系数区表现出春-夏-秋-冬季逐渐北推西进然后东退南落的演变特征,但均方根误差在不同月份、不同区域的偏差量级有所差异。对于区域平均降水量的年际变化,模式基本为正相关系数,且随着预报时效临近相关系数越高,但均方根误差改善不明显。Based on the daily precipitation forecast data for the next 45 days with NCEP CFSv2 model and station observation data,the prediction skills for monthly spatial patterns and interannual variations of precipitation over southwest China were evaluated.The results show that except the wet bias in the northeastern Sichuan and northeastern Chongqing in rainy season(from May to September),there are almost dry bias in other regions and months.The months with significant bias are mainly concentrated in summer.The regional average bias shows an upward-downward-upward trend from January to December,with the highest in April and the lowest in October.As the leading time increases,the prediction skills of spatial patterns decrease,but the prediction skills of magnitudei increase.In different leading times,the“Ω”trend prediction of the model in moderate rain days,heavy rain days and rainstorm days is basically correctly,but the light rain days show opposite characteristics with observations.The prediction of light rain and moderate rain days is higher than that of observation,but the forecast of heavy rain and rainstorm days is lower than that of observation.In interannual variations,the model is predicted to be positive correlation in most areas,while negative skills are mainly concentrated in Sichuan Basin to the western Sichuan Plateau and the border areas of Chongqing,Sichuan,and Guizhou provinces.The high correlation coefficient region reflects the process of gradually pushing northward and westward from spring,summer,autumn and winter,and then retreating eastward and southward.However,the magnitude of root mean square error(RMSE)is distinct in different months and regions.For the interannual variation of regional average precipitation,there is basically positive correlation coefficient,and the correlation coefficient is higher as the forecast time is approaching,but the RMSE improvement is not obvious.

关 键 词：降水预测 西南地区 模式评估 NCEP CFSv2 

分 类 号：P456.7[天文地球—大气科学及气象学]