三套再分析资料的中国夏季降水日变化特征  

The Characteristics of Summer Precipitation Diurnal Variations in Three Reanalysis Datasets over China

作　　者：戴泽军[1,2] 宇如聪[3] 李建[3] 陈昊明[3] 

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [2]中国科学院研究生院,北京100039 [3]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《气象》2011年第1期21-30,共10页Meteorological Monthly

基　　金：国家重点基础研究发展计划(2010CB951900);国家自然科学基金项目(40625014,40921003)共同资助

摘　　要：利用台站观测降水,评估分析了三套再分析(NCEP,ERA40和JRA25)降水资料对中国夏季降水日变化的再现能力。结果表明,三套再分析资料呈现的中国夏季降水日变化特征较观测存在明显偏差。对比台站观测的白天(08—20,北京时)和夜间(20 08时)降水比例,再分析降水在大部分区域都表现为白天较夜间偏多,NCEP和ERA40在观测降水量最小的上午(08—14时)偏多更为明显,且NCEP模拟的白天和夜间的降水比例在西南地区与台站观测几乎相反。相比之下,三套再分析资料中,JRA25的降水量和降水频次的日变化与观测最为接近;NCEP的降水强度日变化最接近观测;ERA40可部分再现西南的夜雨特征。The characteristics of summer precipitation diurnal variations in three reanalysis datasets （NCEP,ERA40 and JRA25） over China were analyzed by comparing with those in station rain gauge observations. Results show that the summer precipitation diurnal variations in the three reanalysis products all present obvious deficiencies.Analyzing the percentages of daytime and nighttime rainfall show that the percentage of the daytime（08-20 BT） rainfall to the whole day rainfall is larger than that of nocturnal（20 -08 BT） rainfall in all reanalysis datasets over the most region of China while comparing with the station gauge data.Further analyses demonstrate that the percentage of the morning（08-14 BT） rainfall is the smallest in the station gauge data,but in NCEP and ERA40 products it is obviously more than that in the station observations.The proportion of the daytime rainfall to nocturnal rainfall in NCEP products over Southwest China is almost reverse to that of station rain gauge data.Generally,the diurnal variations of precipitation amount and frequency in JRA25 products and precipitation intensity in NCEP products are closest to the corresponding components in station data,but the nocturnal rainfall over Southwest China is only partly reproduced by ERA40 products.

关 键 词：夏季降水 日变化 再分析资料 

分 类 号：P434.4[天文地球—大气科学及气象学]