1960-2010 年中国天山山区气候变化区域差异及突变特征

利用天山山区32 个气象站点1960-2010 年的逐月平均气温、降水数据和DEM数据等,进行了气候时空变化趋势和突变分析,研究结果表明：山区近50 年来年均气温呈明显的上升趋势,21 世纪以来年均温增加最明显,季节均温与年均温的变化趋势基本一致,冬季均温增加最明显,夏季均温变化最小;山区东段升温趋势最明显,北坡的变化趋势明显于南坡.自20 世纪60 年代以来降水量持续递增,其中80 年代开始更加明显;夏季降水量增加最明显,春季变化最小,山区年降水主要集中在春夏两季;山区气候空间分布呈现“两中心”的特征,东段为“干热”中心,西北部为“暖湿”中心,这两个中心的气候反差有扩大的趋势;山区气温和降水突变不太明显,春夏季气温突变可能发生在20 个世纪90 年代末至21 世纪初;秋冬季气温突变在20 世纪90 年代可能发生过;南坡和东段年均温突变可能发生在1982 年,北坡大致发生在1990 年左右.秋季降水突变发生在20 世纪80 年代末,其他季节不明显,年降水突变发生在80年代末期.

The Regional Difference and Abrupt Events of Climatic Change in Tianshan Mountains during 1960-2010

The data of monthly temperatures and precipitations during 1960-2010 from the 27 meteorological stations in the Tianshan Mountains, combined with DEM data, are used for the analysis of the temporal and spatial trends of climate changes, including some abrupt changes. As shown in the results: (1) annual average temperatures have shown a clear upward trend, with more dramatic temperature increases in the years of this century. The seasonal averages are changing in a similar fashion with the annual averages, with the winter averages showing the highest increases and the summer averages the lowest increases. The east side of the mountains shows the most striking trend of temperature increase, and temperature change on the north is more than that on the south. (2) Precipitationshave kept increasing since 1960’s, and the increase accelerates after 1980’s. Summer precipitations show the biggest increase, and spring precipitations show the smallest increase. The annual precipitation in the mountain regions are mainly contributed by summer and spring. In the spatial scale, the mountain climate shows a“two-center”pattern, with a center of“hot and dry”on the east, and a center of “warm and wet”on the northwest, and the contrast between the two is in the trend of expanding. (3) Abrupt changes in temperature and precipitation in the mountain regions are not evident. Spring and summer temperatures may have had abrupt changes in late 1990’s to early 2000’s, while abrupt changes to autumn and winter temperatures may have happened during 1990’s. There may be an abrupt change of annual temperature on the south and east side in 1982, on the north side roughly in 1990. An abrupt change of autumn precipitation occurs in the late 1980’s, but for other seasons there are not obvious abrupt changes. Annual precipitation has an abrupt change in the late 1980’s.