1961-2010年青藏高原气候变化特征分析

Using the data of temperature (including average temperature, minimum and maximum temperatures), precipitation and wind speed from 158 meteorological stations in the Qinghai-Tibet Plateau and its surrounding areas from 1961 to 2010, the characteristics of climate change in the Qinghai-Tibet Plateau were analyzed. The results show that: (1) From 1961 to 2010, the main part of the Qinghai-Tibet Plateau is becoming warmer and wetter, but some areas on the eastern side of the plateau are becoming warmer and drier, and at the same time the overall wind speed on the plateau is decreasing. (2) The temperature rise is mainly contributed by the minimum temperature at night. There are differences in the warming rates in different regions, with the central region being higher than the eastern region; the average temperature and the maximum temperature underwent abrupt changes in 1994 and 1997 respectively, and the warming rate increased significantly after the abrupt changes; there are quasi-8-year periodic oscillations for all three temperatures, and the manifestations of other short-period and longer-period oscillations are inconsistent. (3) The spatial distribution of precipitation shows a gradual decrease from the southeast to the northwest, and there have been multiple abrupt changes, with the abrupt change times being 1965, 1977 and 1995 respectively. The change rates of precipitation before and after the abrupt changes are significantly different, and there are quasi-4-year and quasi-10-year periodic oscillations in precipitation. There is an 18 - 20-year periodic oscillation in wind speed. (4) The first loading vectors of the EOF decomposition of the average temperature, minimum temperature and maximum temperature in the Qinghai-Tibet Plateau all show positive values consistent across the whole region, and the central area is located in the 94°E - 97°E zone, indicating that the hinterland of the Qinghai-Tibet Plateau is the most sensitive area for the changes of the average temperature, minimum temperature and maximum temperature. (5) The second loading vectors of the EOF decomposition of the average temperature, minimum temperature and maximum temperature generally show that the change trends of the main part of the plateau are opposite to those of the eastern and northern marginal zones, that is, when the main part of the plateau is warming (cooling), the eastern and northern marginal zones are cooling (warming).

利用1961-2010年青藏高原及其周边地区158个气象站温度(包括平均温度、最低和最高温度)、降水和风速资料,对青藏高原的气候变化特征进行了分析。结果表明:(1)1961-2010年青藏高原主体正在变暖变湿,但是高原东侧部分地区正在变暖变干,同时高原整体风速都在减小。(2)升温主要是夜间的最低温度贡献的。不同地区升温速率有差异,中部地区高于东部地区;平均温度和最高温度分别在1994年和1997年发生突变,突变后升温速率明显加快;三种温度都存在准8年周期震荡,其他短周期及更长周期震荡表现不一致。(3)降水量空间分布上表现为从东南向西北逐级减少,并且出现过多次突变,突变时间分别为1965年、1977年和1995年,突变前后降水的变化速率明显不同,降水存在准4年和准10年周期震荡。风速存在18~20年周期震荡。(4)青藏高原平均温度、最低温度及最高温度EOF分解的第一载荷向量均表现出全区一致的正值,中心区位于94°E-97°E一带,说明青藏高原腹地是平均温度、最低温度及最高温度变化最敏感的地区。(5)平均温度、最低温度及最高温度EOF分解的第二载荷向量大体表现出高原主体与东部以及北部边缘地带变化趋势相反,即高原主体升温(降温)时,东部及北部边缘地带是降温(升温)的。