天山典型区卫星雪盖时空特征研究

Spatial and Temporal Characteristics of Satellite Snow Cover in a Typical Area of Tianshan Mountains

基于2000—2010年的MODIS/Terra积雪8 d合成数据(MOD10A2),研究了我国天山典型区积雪覆盖的空间分布特征和年际变化趋势.结果表明:年平均积雪概率和1月积雪概率均呈西高东低、北高南低的分布格局,4月、7月、10月的积雪概率与高程呈显著的正相关;冬季积雪分布主要受大气环流控制,使得西坡和北坡的积雪明显较为丰富,而春、夏、秋季的积雪分布受高程的影响最为显著.近10 a来冬季积雪覆盖率总体呈下降趋势,线性倾向率为-0.087.(10 a)-1,而春季则略有上升,线性倾向率为0.034.(10 a)-1;随着高程上升,积雪覆盖度的年际波动幅度呈减小趋势.

The spatial and temporal characteristics of satellite snow cover in a typical area of Tianshan Mountains are studied based on the remote sensing snow cover product（MOD10A2） from 2000 to 2010.The results show that： 1） the annual average snow cover probability and the snow cover probability of January both decrease from west and north to east and south,while the snow cover probability of April,July and October have a significant positive correlation with elevation;2） the distribution of snow in winter is mainly controlled by the atmospheric circulation,so that there is much more snow on the west slopes and the north slopes,while the distribution of snow in the other seasons is significantly influenced by elevation;3） in the past 10 years,the snow cover ratio in winter generally has decreased with a linear trend rate of-0.0875（10a）＋-1,while it has slightly increased in spring with a linear trend rate of 0.0345（10a）＋-1;and 4） with the ascending of elevation,the interannual fluctuation of snow coverage shows a trend of decrease.