青藏高原地区近40年来气候变化的特征

The Features of the Climate Changes in the Qing-Zang Plateau Area During the Last 40 Years

根据青藏高原地区气象台站上温度和降水量资料,统计分析得出:50年代比60年代暖,60年代比70年代冷,70年代比80年代冷。在这40a期间,最暖的是80年代,它主要体现在冬季温度偏高较多;其次是50年代,这时主要是夏季温度偏高明显。最冷的是60年代,这期间秋、冬季温度偏低明显。70年代基本上是趋于正常,略有一点偏暖。降水量是50年代比60年代少,60年代比70年代少,70年代比80年代少。也就是说,从50年代以来,降水量是趋于逐渐增加的趋势。综合温度和降水量变化的特点,青藏高原地区40a中的气候变化状况是,50年代为暖干期,60年代为冷干期,70年代则为一种弱的暖湿期,80年代整个高原上为暖湿期。从趋势分析来看,青藏高原上的增温是从70年代就已开始。温度的上升幅度达0.5℃左右。另外青藏高原地区的增温不仅仅发生在地面上,而且在高空也有其表现。特别是100hPa高度较为明显。

On the basis of the meterological date in the Qing-Zang Plateau area, the character and tendency of temperature and precipitation changes were analyzed. The results show that the temperature was warmer in the fifties than that of the sixties, the colder in the sixties than that of the seventies, and the colder in the seventies than that of the eighties. During 40 years, the most warm time occured in the eighties, its primary charecter reflects in the high temperature of winter season, the most cold time occured in the sixties, its primary charecter reflects in the high temperature of autumn and winter season. Precipitation was increasing gradualy from fifties to eighties. Synthesizing the charecter and tendeny of the variation of tempareture and precipitation, it is found that the feature of the climate conditions during the last 40 years is warm and dry in 1950's, cold and dry in 1960's, weak warm and wet in 1970's, and warm and wet in 1980's. For the tendeny of climate variation, the rise of temperature occured in 1970's, the rise amplitude is 0.5℃. On the other hand, the rise of temperature in the Qing-Zang Plateau area not only occures in the surface, but also occures in the upper at mosphere, and especially in 100 hPa level.