NCEP/NCAR和ERA-40再分析资料以及探空观测资料分析中国北方地区年代际气候变化

The Assessment and Difference of the Interdecadal Variations of Climate Change in Northern Part of China with the NCEP/NCAR and ERA-40 Reanalysis Data

利用中国东部的探空站资料以及ERA40和NCAR/NCEP再分析资料,详细地比较了我国北方地区(主要指内蒙古以及华北地区)的高低层位势高度以及温度的特征。结果表明,在20世纪70年代以前,NCEP/NCAR再分析资料对我国北方地区对流层低层无论是位势高度或温度都描述不好,存在着很明显的虚假年代际变化趋势。与实际探空资料相比,相对于NCEP/NCAR再分析资料,ERA-40再分析资料对东亚地区对流层低层位势高度或温度的描述明显好于NCEP/NCAR再分析资料,因此,研究东亚气候的年代际变化应用ERA-40再分析资料要好一些。高层的结果要比低层好。在70年代以后,NCEP/NCAR再分析资料对于内蒙古和华北对流层上层的位势高度和温度的描述要好于ERA-40再分析资料,更接近于实际探空值,这说明这两份再分析资料各有优缺点。

Based on the sounding datasets over the eastern part of China, ERA-40 and NCAR-NCEP reanalyses, we compare the characteristics of the geopotential highs and temperatures at lower and upper troposphere over northern part of China （particularly in Nei Mongol and North China）. It is found that before 1970s, the geopotential heights and temperatures at lower and upper troposphere from NCEP-NCAR reanalyses do not agree well with the observations, the existing interdecadal trend is unrealistic, but the ERA-40 datasets are much closer to those of observations in the long-term trend. However, after the 1970s, the upper troposphere geopotential heights and temperatures from NCEP-NCAR reanalyses is better than ERA-40 reanalyses, which is more closer to those of observations. In other words, these two reanalyses have their own shortcoming over the northern part of China.