新疆北部地区季节性积雪密度变化特征分析

Analysis on the Seasonal Snow Density Change Characteristics of North Xinjiang

选取新疆北部地区季节性积雪期的定点站和典型区域,应用北疆20个气象站点观测资料和使用便携式测雪仪(Snow Fork),在不同地域、不同雪层和不同时间进行观测与测量,并且在积雪稳定期中的一次降雪过程对新雪密度变化过程中影响它的诸多因子进行观测,对新疆北部地区冬季季节性积雪密度变化特征进行的观测和分析.结果表明:雪面辐射热量和雪层内温度梯度对积雪密度起主要作用,变化主要是通过雪层内深霜和粗粒雪层的温度减小而实现的;在隆冬期全层积雪密度最大的为深霜层,入春2月下旬回暖期以后,由于雪层含水率的增加,季节性积雪密度最大层则为粒雪层.

Snow cover in north Xinjiang is important to climate,water resources and ecological environment.This paper observed and analyzed the seasonal snow density change characteristics of north Xinjiang.We did field observation on different snow layers in different regions and time and observed the influence factors of snow density change in a snow process at the snow stable stage with the portable equipment Snow Fork.Based on the observational data from 20 weather stations and the field observation data,we analyzed the snow density change characteristics by the principal component analysis method.The results showed as follows： the radiation heat of snow surface and temperature gradient between snow layer dominate the snow density change;the decrease of temperature in deep frost layer and coarse snow layer would change the snow density;in severe winter,the maximum density layer is deep frost layer;after late February,the maximum density layer in particle snow layer because of the increase of water content.