针对20CR、CFSR、NCEP1、NCEP2、ERA-Interim、ERA-20CM和JRA-55再分析位势高度和风场资料,基于探空资料,采用计算均方根误差、相关分析等方法从气候均值、长期变化趋势和年际变率三个方面评估再分析资料在青藏高原地区的适用性.结果表明:再分析资料的适用性存在季节、空间和垂直层次上的差异.气候均值方面,NCEP1和ERA-Interim位势高度资料与观测资料最接近,适用性最佳,而ERA-20CM资料偏差最大.春夏季,NCEP2和NCEP1的风速资料质量较优,20CR和ERA-20CM资料质量相对较差;而秋冬季,ERA-20CM风速资料与探空资料最接近,质量最好.气候变化趋势方面,JRA-55、ERA-Interim和NCEP1资料质量存在时空的差异,但均能很好地反映出位势高度的变化趋势.年际变率方面,除了ERA-20CM,各再分析资料与探空资料相关性高,对年际变率的刻画基本一致,其中JRA-55和ERA-Interim位势高度资料与探空资料相关性最好.就季节而言,冬季再分析资料质量最高,适用性好,其次为春季,夏季资料质量最低.
In this study,the applicability of geopotential height and wind velocity reanalysis data is evaluated,including 20 CR,CFSR,NCEP1,NCEP2,ERA-Interim,ERA-20 CMand JRA-55 reanalysis datasets,over the Tibetan Plateau by compared with radiosonde data. The analysis is focused on climatology,climate change and annual variation by means of various statistical analysis methods( root mean square error,correlation analysis,etc.). It is found that there are many clear differences among the reliabilities of reanalysis datasets,seasonal,regional and vertical. Geopotential heights of NCEP1 and ERA-Interim are comparatively closest to observation data in climatology. In contrast,the error of ERA-Interim and ERA-20 CMdata is large. In spring and summer,the reliability of reanalysis data of NCEP1 and NCEP2 wind velocity are higher than that of other reanalysis data,while during autumn and winter ERA-20 CMwind velocity data is better. Based on the comparison in climate change trend,one can see that JRA-55,ERA-Interim and NCEP1 reanalysis data are able to objectively represent the geopotential height changing trend,with some temporal and spatial disparities. For annual variation,reanalysis datasets and radiosonde data almost get consistent description,except for ERA-20 CM. Seasonally,reanalysis datasets showhigher reliability in winter,followed by spring,with a poor reliability in summer.