青藏高原及其四周的近代气候变化

本文首先研究了近千年来高原及其四周的气候变化,表明青藏高原是百年尺度气候变化的“启动区”,并用有近百年记录的Leh和Srinagar两站间的温度垂直递减率与降水距平百分率的10年滑动平均求相关,结果表明高原上的降水与气温垂直变率密切相关,降水多的年代高原内部温度高、外部低,反之亦然,完成一个振荡的周期约40年。其次分析了近30多年高原及其四周的气候变化,发现在北半球降温的60年代随着行星西风的加强,背风下沉区降水明显减少,向风区则增多。到了70年代高原北部夏季风开始增强,沙漠区降水开始增多。最后根据以上分析结果对中国西部至本世纪末的气候变化趋势作了初步预测,认为中国西部至少到本世纪末将继续升温,高原东西两侧的降水呈现“东升西降”的态势。

THE CLIMATE CHANGE OF QINGHAI-XIZANG PLATEAU AND ITS NEIGHBOURHOOD

In this paper, firstly we have discussed climate change of the Qinghai -Xizang Plateau during the recent thousand years. It is found that Qing-hai-Xizang Plateau is a climate change "source region" of the East Asia. The lapse rate of air temperature between the two stations Leh and Srina-gar and the rainfall anomaly (percent departure from normal) of those stations are closely related according to the data of about one hundred years. When air temperature is higher, the rainfall is more, and vice versa. These oscillating period is about 40 years. Secondly, the climate change of plateau and its neighbourhood in the recent 30 years is analyzed. We have found when the air temperature of Northern Hemisphere was dropping in the 1960's, the rainfall in the windwards side of the plateau was increasing and the rainfall in the lee side was getting less. Until the 1970's the rainfall in the desert was increasing due to the strengthening of wet monsoon over the north side of the plateau. Finally, according to the data analysis , it will be expected that the air temperature of the west part of China will go up, the rainfall will be rising by the east side of the plateau and go down in the west side up to the end of this centenary.