基于2001—2018年MOD10A2积雪产品和MOD11A2陆地表面温度数据,采用精细分区统计和相关性分析方法,研究了中国天山不同海拔高度上积雪垂直分布特征及其与地表温度（Land surface temperature,LST）的响应关系。结果表明：中国天山积雪覆盖率（Snow cover percentage,SCP）随海拔的变化呈现春、夏、秋、冬4种不同的季节变化模式。SCP在海拔4200 m以下呈秋冬季增加、春夏季减少态势,在海拔4200 m以上呈秋冬季减少、春夏季增加态势。除冬季外,春、夏、秋3个季节的SCP与LST均具有显著强负相关性。

Vertical variation of snow cover is important to understand the snow accumulation and decay, especially in topographically complex montane terrains, and was used in snowmelt runoff modeling and assessment of climate change impact on snow cover. On the basis of the snow product of MOD10A2 and land surface temperature (LST) data of MOD11A2 during 2001—2018, this study analyzed the vertical distribution of snow cover and its response to LST in Chinese Tianshan Mountains using zonal statistics and correlation analysis methods. The following results were obtained from the analysis: snow coverage percentage (SCP) showed four different seasonal patterns in spring, summer, autumn, and winter. The SCP in winter changed largely when the altitude rose. The SCP increased and then declined below 1200 m asl and reached the peak at 4000-4200 m. In addition, the SCP in spring and autumn increased gently and fell consistently with change in the altitude, and the peak of SCP was between 4800 and 5000 m asl. The SCP in summer rose significantly above 2800 m asl and reached the peak at 4800-5000 m asl and then fell rapidly. The intra-annual variation in SCP showed significant seasonal characteristics. The vertical distribution of SCP in high-altitude zones (E and F) in Chinese Tianshan Mountains was inverse to that in the middle- to low-altitude zones (A, B, C, and D) from October to April, but both of them were sensitive. The SCP was most sensitive to the relative middle-altitude zones (C and D) from May to September, whereas it was insensitive in the other four zones. The SCP in the A, B, E, and F districts had no change from April to October, and their changes were not sensitive compared with that in the C and D districts. Snow under 4200 m asl or less increased in autumn and winter and decreased in spring and summer, but this tendency was opposite for that above 4200 m asl. A strong negative correlation existed between SCP and LST in spring, summer, and autumn, and the correlation coefficient increased with rising altitude. The poor correlation in winter may be related to more snowfall in low-altitude areas, wind-blown snow effect, and temperature inversion in high-altitude areas. The negative correlation between SCP and LST initially increased and then decreased with the increase in the altitude. LST had the greatest influence on SCP from 3200 to 4200 m, whereas it had the least influence on SCP from 3200 to 4200 m because LST had no altitude gradient effect at altitudes below 1000 m and above 4200 m. Therefore, the negative correlation between SCP and LST in this region was not very strong. This study discussed in detail the vertical distribution of snow cover in Chinese Tianshan Mountains, which had a practical significance for snowmelt runoff in mountainous areas, rational dispatching, and utilization of water resources, combating snow disasters in pastoral areas in winter and flood disasters in spring and summer.