中国区域再分析湿度资料与均一化探空湿度资料的对比分析

Comparisons of Atmospheric Specific Humidity in Reanalysis Datasets and Homogenized Radiosonde Dataset in China

利用1980—2010年中国98个探空站均一化月平均温度和温度露点差资料(OBS)和NCEP/NCAR(NCEP)、ERAInterim(ERA)、JRA-25(JRA)3种再分析月平均比湿资料,使用相似分析、趋势分析等方法对中国区域4种资料高空比湿进行了对比分析。结果表明:(1)从空间分布特征分析,JRA比湿与OBS比湿的空间分布相似系数最大。(2)3种再分析资料比湿普遍大于OBS比湿,除个别站点个别层次外,JRA和OBS比湿更加接近;再分析比湿和OBS比湿的相对偏差随高度增加而增大,且冬春季大于夏季。(3)从长期变化趋势分析,在对流层低层,JRA和0BS比湿较接近,在对流层中高层ERA和OBS比湿较接近。

Based on monthly mean homogenized radiosonde temperature and dewpoint depression dataset from 98 stations in China during the period 1980-2010,NCEP/NCAR reanalysis dataset,ERA-Interim reanalysis dataset and JRA-25 reanalysis dataset,a comparative analysis of specific humidity from these four datasets over China is performed by means of analogical analysis and tendency analysis.The results suggest that:(1) In terms of spatial distributions,the spatial correlation coefficients between JRA and OBS datasets are the highest.(2) The values of three reanalysis datasets are generally higher than that of radiosonde dataset,JRA dataset is much closer to observed dataset except for several stations and levels.Relative tolerance between reanalysis and radiosonde datasets increases with height and it is higher in winter and spring than in summer.(3) When it comes to the long term trend,JRA is closer to OBS in lower troposphere,and in middle and upper troposphere,ERA is much closer to OBS.