西宁和沱沱河地区近地面及500hPa温度变化的对比分析

Temperature Variations at the Surface and 500 hPa in Xining and Tuotuohe Regions

根据青藏高原西宁、沱沱河站的近地面和５００ｈＰａ温度资料，对比分析了不同层次年、季平均温度变化的趋势以及高低空两个站之间温度变化的差异。结果表明，西宁站近地面年平均温度变化有明显的增温趋势，３８ａ来增温幅度约１℃。沱沱河站年平均温度未见明显的增温趋势，这主要是由于１９８５～１９８６年沱沱河地区罕见的暴风雪灾害导致的创记录的秋、冬季低温所引起的。但在夏季温度变化上，仍可看到明显的增温趋势；在５００ｈＰａ，西宁、沱沱河站的季、年平均温度变化相似，没有明显的增温现象。与近地面温度不同，自１９８８年以后，５００ｈＰａ已连续４ａ温度下降。

Based on the temperature data at the surface and 500 hPa at Xining and Tuotuohe located in the Tibetan Plateau, this paper analysed the trends of annual and seasonal mean temperature variations on different levels, and differences between the temperature variations of two levels and of the two stations. The results show that the variations of annual mean temperature had a disinctly warming trend at the surface at Xining. The mean annual temperature from the end of 1980s to the beginning of 1990s increased about 1℃ compared with that from the end of 1950s to the beginning of 1960s; No obviously warming trend was found at the same time of annual mean temperature at Tuotuohe, due to an exceptionally serious snowstorm which resulted in a low temperature in Tuotuohe region from 1985 to 1986, but a slightly warming trend could be seen in summer. At 500 hPa no obviously warming trends of seasonal and annual mean temperature were found at Xining and Tuotuohe, and even after 1988, the annual mean temperature decreased for four consecutive years, which was different from that at the surface.