全球变暖背景下青藏高原气温和降水的气候变化特征

Characteristics of Temperature and Precipitation Change on the Tibet Plateau under the Background of Global Warming

摘要: 本文使用1979~2018年欧洲中期数值预报中心地表气温和降水逐月再分析数据，利用最小二乘法、回归分析、显著性检验等统计学方法研究了青藏高原气温和降水的空间分布特征以及变化敏感区域的趋势特征。结果表明：1) 青藏高原整体气温明显低于周边地区的温度，高原上的气温自西向东逐渐增长，四季气温差异明显。高原上存在两个明显的气温低值中心，分别是昆仑山地区和祁连山附近，高值中心位于柴达木盆地地区。2) 青藏高原南北两地的年降水量差异明显，从高原西北部到东南部，降水逐渐增多，主要降水中心位于雅鲁藏布江地区，次降水中心位于川西高原地区。高原上有旱季和雨季之分，大部分地区降水集中在夏季，冬季则为一年中的旱季。3) 高原整体呈现出增温的趋势，且存在五个气温变化较为敏感的区域，中部的敏感区域增温明显。4) 青藏高原上大部分地区降水未呈现出明显的变化趋势，降水显著减少的区域为唐古拉山东部和雅鲁藏布大峡谷地区，降水显著增加的区域为高原西南部的藏南谷地和高原东部的西宁地区。

Abstract: In this paper, the monthly reanalysis data of surface temperature and precipitation (resolution 0.125˚ × 0.125˚) of ECMWF from 1979 to 2018 were used to study the spatial distribution charac-teristics of air temperature and precipitation on the Qinghai-Tibet plateau and the trend charac-teristics of the change sensitive areas by using the least square method, regression analysis, significance test and other statistical methods. The results show that: 1) the overall temperature of the Qinghai-Tibet plateau is significantly lower than that of the surrounding areas, and the temperature on the plateau gradually increases from west to east, with a significant difference in the temperature of four seasons. There are two obvious low temperature centers on the plateau, namely the Kunlun mountain area and the Qilian mountain area, and the high temperature center is located in the Qaidam basin area. 2) There is a significant difference in annual precipitation between the north and south of the Qinghai-Tibet plateau. Precipitation gradually increases from the northwest to the southeast of the plateau. The main precipitation center is located in the Yarlung Zangbo river region, and the secondary precipitation center is located in the western Sichuan plateau region. There are a dry season and a rainy season on the plateau. Precipitation in most areas is concentrated in summer, while winter is the dry season of the year. 3) The plateau as a whole shows a trend of increasing temperature, and there are five areas with relatively sensitive temperature changes, and the sensitive areas in the middle of the plateau show a significant increase in temperature. 4) Precipitation in most areas of the Qinghai-Tibet plateau did not show an obvious change trend. The regions with significant decrease in precipitation were the eastern Tanggla Mountain and the Yarlung Zangbo Grand Canyon, while the regions with significant increase in precipitation were the south Tibet valley in the southwest of the plateau and the Xining region in the east of the plateau.