1961—2017年新疆积雪期时空变化特征及其与气象因子的关系

利用新疆89个地面站逐日积雪深度观测资料，研究探讨了1961—2017年新疆区域积雪期、积雪初日、积雪终日的时空变化规律，分析了北疆和天山山区积雪期的年代际和周期变化特征及其与气温、降水的关系。结果表明：新疆各地积雪期、积雪初日和终日存在明显的差异，积雪期以天山为界北多南少；从空间分布看，天山山区和新疆北部阿勒泰、塔城和伊犁河谷的大部地区是新疆积雪最丰富的地区，也是积雪期相对较长的区域。近57年来，北疆和天山山区78%气象站积雪期呈减少趋势，其中塔城地区和阿勒泰东部以及中天山一带的部分地区减少显著；67%气象站积雪初日推迟，显著推迟区域与积雪期显著减少的区域基本一致；积雪终日变化趋势不明显。北疆和天山山区积雪期存在2~3 a的短周期、14~15 a的长周期；积雪初日分别以12 a、15 a长周期振荡为主，但3~5 a短周期振荡出现的时段有所差异，两个区域积雪终日周期信号均较弱。北疆和天山山区积雪期、积雪初日和终日受气温的影响大于降水，其中积雪初日、终日出现的早晚与其所处季节的平均气温显著相关。

Spatial-temporal variation characteristics of snow cover duration in Xinjiang from 1961 to 2017 and their relationship with meteorological factors

Based on the daily observations of snow cover at 89 meteorological stations in Xinjiang from 1961 to 2017， the spatial-temporal characteristics of initial snow cover date， final snow cover date and snow cover duration in Xinjiang were studied. The periodicity and inter-decadal variations of snow cover， and their relationship with temperature and precipitation in northern Xinjiang and the Tianshan Mountains were also studied. The results showed that： There were distinct differences in initial snow cover date， final snow cover date and snow cover duration over Xinjiang. The snow cover duration on the north slopes of the Tianshan Mountains was longer than that on the south slope. In terms of spatial distribution， Tianshan Mountain， Altay， Tacheng and Ili River valley had abundant snow cover and a relatively long snow cover duration. In the past 57 years， the snow cover duration had showed a decreasing trend in 78% of meteorological stations in northern Xinjiang and the Tianshan Mountains， with a pronounced reduction in the middle Tianshan Mountains， Tacheng region and the eastern Altay. The initial date of snow cover delayed around 67% of meteorological stations， while the final date of snow cover had showed no significant change. The oscillation of snow cover duration in northern Xinjiang and the Tianshan Mountains had exhibited a 2~3 years short period and a 14~15 years long period； the initial date of snow cover in northern Xinjiang and the Tianshan Mountains had been dominated by 12 years and 15 years long-period oscillations， respectively， with a consistent 3~5 years short period oscillation occurring in different time. The final date of snow cover had not showed explicit periodicity. The influence of air temperature on the snow cover duration had been more significant than that of precipitation in northern Xinjiang and the Tianshan Mountains； the initial and final date of snow cover were remarkably correlated with the seasonal mean air temperature.