北疆地区季节性积雪物理特性分析

Analysis of Physical Characteristics of Seasonal Snow in Northern Xinjiang

季节性积雪以其特殊的物理特性对寒旱区生态系统、冰雪水文过程及气候系统均产生显著影响,为研究北疆地区季节性积雪物理特性,选择在天山北坡乌鲁木齐河流域下游试验区有无遮蔽条件下(林冠下、开阔地)进行,利用SnowFork雪特性分析仪采集2018年12月1日~12月31日内积雪物理特性(积雪深度、积雪密度、体积含水率)数据,分析该时段内积雪物理特性的时间变化特征及其在垂直剖面上的廓线分布。结果表明:①在观测期内,林冠下积雪累积深度小于开阔地;②林冠下与开阔地雪层密度从新雪层到深霜层均表现为先增大后减小,分别在中粒雪层与粗粒雪层达到峰值,林冠下平均密度小于开阔地;③林冠下含水率自新雪层至深霜层不断增大,在深霜层达到最大,开阔地含水率呈现单峰变化,在粗粒雪层达到最大,且开阔地略高于林冠下。

Seasonal snow has significant effects on ecosystems, ice and snow hydrological processes, and climatic systems in its cold and arid regions due to its special physical characteristics. To study the physical characteristics of seasonal snow in northern Xinjiang, a trial was conducted in the lower Urumqi River basin on the northern slope of the Tianshan Mountains. The data were collected under snow-covered conditions(under the forest canopy and in open areas), and the physical characteristics(snow depth, snow density, volumetric water content) of snow cover from December 1, 2018 to December 31 were collected using the SnowFork snow characteristic analyzer., Analyze the time-varying characteristics of the physical characteristics of snow cover and its profile distribution on the vertical section during this period. The results show that: ① the accumulated depth of snow under the forest canopy is less than that of the open land during the observation period;②the density of the snow layer under the canopy and the open land from the new snow layer to the deep frost layer increases first and then decreases,respectively in the medium-grain snow layer and The coarse-grained snow layer reached its peak, and the average density under the canopy was smaller than that in the open land. ③The water content under the canopy increased continuously from the new snow layer to the deep frost layer, reaching the maximum in the deep frost layer, and the water content in the open land showed a single peak change. Reached the maximum, and the open area was slightly above the canopy.