1975-2008年青藏高原冬季气温变化

Winter temperature variation in the Qinghai-Tibetan Plateau in 1975-2008

利用青藏高原及周边地区89个气象台站33年冬季月平均地表气温观测资料以及NECP/NCAR再分析资料,用统计学方法对该地区冬季气温变化作了分析研究,得到其整体变暖的变化趋势,该区域升温的线性趋势是0.6℃/10a。此外,由于高原台站分布不均匀,又分别从垂直方向和水平方向对高原冬季气温变化做了初步的分析。结果表明:青藏高原冬季气温整体变化趋势在增暖的同时个别区域也存在降温的趋势,600 hPa温度以及温度梯度随纬度增加而增加,而且随海拔高度的增高,增温趋势减小,到达一定海拔高度出现降温趋势,高原海拔高度较低的近地面层气温变化最明显。

With an analysis of the NECP reanalysis data and 33 a of monthly averaged winter temperature data from the plateau itself and from the 89 meteorological stations within its surrounding areas, an overall warming trend was shown. Statistical methods were used in the analysis of the winter temperature variation. In addition, as a result of the uneven distribution of the plateau stations, a preliminary analysis of change in winter temperatures was done from the vertical and horizontal directions. The result showed that, though an overall increase of winter temperature appeared in the Qinghai-Tibetan Plateau that the variation of 0.6 ℃/10 a, some individual regions actually cooled down. The 600 hpa temperature and temperature gradient changed along with latitude. And the warming up trend was negatively correlated with altitude increase until the cooling down trend was observed in the designated altitude. The vertical direction corresponding to the temperature, as well as the rate of warming up or cooling down is different. The most obvious change in temperatures was observed in the near surface layer within the lower altitude area of the plateau.