天山季节性积雪稳定期雪密度与积累速率的观测分析

Densification and Accumulation Rate of Snow in the Stable Snow Cover Period in the Tianshan Mountains

利用Snow Fork雪特性分析仪测量的天山积雪雪崩站2009年2月21-26日及2010年1月26-31日雪特性数据,分析了季节性积雪稳定期内积雪垂直剖面密度的变化特征及其随降雪沉积时间和雪层深度的变化规律.结果表明:季节性积雪稳定期内,积雪剖面密度中部最大,表层和底层密度较低;新雪层密度随时间的推移增加速率逐渐增大,细粒雪层、中粒雪层、粗粒雪层和深霜层密度随时间推移增加速率逐渐减小;不同深度雪层密度随深度变化呈现出规律性的变化.通过建立的雪层密度随降雪沉积时间和积雪深度而变化的经验关系式,可以应用两个极易获取的积雪参数(即降雪沉积时间和积雪深度)来推算不同深度的雪层密度.

A Snow Property Analyzer（Snow Fork） was used to measure the snow density in the Tianshan Station for Snow and Avalanche Research,Chinese Academy of Sciences,in the stable snow cover period from February 21 to 26,2009 and January 26 to 31,2010,the snow density profile and its variations with depth and time were analyzed.It is found that snow density at the upper and bottom layers was smaller than that at the middle layers;the increasing rate of the new-fallen snow density increased with time,but in other snow layers the increasing rate decreased with time;a certain pattern of snow density varying with depth was found.Thus an experiential equation with two simple variables（snow depth and snow sediment time） was established to describe the snow density profile.