民勤荒漠区气候变化对全球变暖的响应

 近年来,全球变暖已成为一个全世界广泛关注的问题。那么,荒漠气候是如何响应全球变暖的呢？以中国西北典型荒漠地区民勤为例进行了分析。结果表明,民勤荒漠区年平均气温的抬升速率高于20世纪全球气温抬升速率和中国近100 a气温抬升速率;2—6月和11—12月月平均气温表现为不同程度增温趋势,其中,2月增温最明显;从20世纪全球最暖的80—90年代开始极端最高气温变幅明显增大,极端最低气温间歇式下降,极端最高气温和极端最低气温的不稳定性增大;在变暖的同时,降水量表现为增加趋势;1956年以来当地沙尘暴发生日数表现为减少趋势,其原因主要是1961年以来当地的空气相对湿度增大,暖湿气候是导致沙尘暴减少的主要原因之一。

Response of Desert Climate Change to Global Warming in Minqin,China

Global warming is a widespread concern around the world in recent years. How does desert climate respond to global warming then? In this paper, Minqin county in Gansu province of China, a typical desert area in northwest China, was selected as an example to analyze the response by the use of temperature data, precipitation, relative air humidity, sandstorm days and other related data since 1961. The increase rate of annual average temperature in the study area was higher than the global increase rate in the 20th century and the last 100 years increase rate in China. Analysis of monthly average temperature showed different increase trend in Nov. to Dec. and Feb. to Jun., and the most significant climate warming happened in February. Change amplitude of the highest temperature increased significantly since 1980s the globally warmest period, but the lowest temperature dropped intermittently. So the instability of the highest and the lowest temperature increased. Analysis of annual precipitation showed an upward trend in the study area. Sandstorm days decreased significantly since 1956, and the increase of relative air humidity since 1961 in the study area was main reason.