1959-2003年中国天山积雪的变化

 利用天山山区17个气象站1959-2003年的气象观测资料，分析了中国天山山区冬季（12-2月）气温、积雪变化趋势特征， 并采用Mann-Kendall统计量对最大积雪深度的变化进行了突变检验，通过GIDS插值方法和DEM数据计算了它的空间分布。结果表明，天山山区冬季平均气温存在明显的上升趋势，倾向率为0.44℃/10 a，与北半球冬季平均气温的变化有着较好的相关性，最低气温的增加更为明显，其倾向率为0.79℃/10 a。45 a来天山山区最大积雪深度具有明显的增加趋势，倾向率为1.15 cm/10 a，检测表明，最大积雪深度在1977年前后发生了突变；与多年平均相比，积雪深度增加幅度最大的是西天山地区的昭苏、尼勒克，分别增加了39.3%和39.7%。天山山区积雪变化以2.8 a左右的周期为主。另外，积雪日数的增加主要出现在≥10 cm的积雪深度上；积雪初、终日期并没有表现出明显的提前或推迟。

Snow Cover Variation During 1959-2003 in Tianshan Mountains, China

The meteorological data (1959-2003) from 17 weather stations in the area of Tianshan Mountainous are analyzed to explore the trend characteristics in temperature and snow cover. The abrupt change test of the snow cover depth is carried out by using Mann-Kendall method, and the spatial distribution of maximum snow cover depth is also given by employing the GIDS interpolation and the DEM data. The results show that winter mean temperature had a rising trend at a rate of 0.44℃/10 a, which is closely related to the mean temperature of the Northern Hemisphere ( r = 0.54). Winter minimum temperature increased at a rate of 0.79℃/10 a, greater than that for winter mean temperature. Maximum snow cover depth in winter has obviously increased at a rate of 1.15 cm/10 a, and in comparison with long-term normal, it has on the average increased by about 16% during the period of 1991 to 2003. The result of the abrupt change test of snow cover depth indicates that the abrupt change occurred in 1977. There were two places, Zhaoshu and Nileke, located in the Western Tianshan Mountains, with the greatest snow cover depth augment of 39.3% and 39.7%, respectively. There was a primary periodicity of about 2.8 years for snow cover. In addition, snow days with the snow cover depth more than 10 cm increased distinctly. There was no obvious change in the beginning and ending dates of snow cover.