积雪属性非均匀性对被动微波遥感积雪的影响

积雪属性的非均匀性在水平方向上表现为像元内积雪未完全覆盖和雪深分布的不均匀,在垂直方向上表现为积雪剖面上粒径和密度的不一致导致的积雪分层现象。这些积雪属性的非均匀性对被动微波遥感反演雪深或雪水当量带来很大的不确定性,并且给反演结果的验证带来不确定性。通过野外积雪的微波辐射特性观测、遥感积雪产品对比分析、积雪辐射传输模型模拟对这些问题进行阐述和探讨,为今后积雪微波遥感反演算法发展和结果验证提供参考。

Impacts on Passive Microwave Remote Sensing of Snow from Heterogeneities of Snow Properties

Heterogeneities of snow properties include the variation of snow depth and the snow cover fraction in the horizontal direction and the variation of grain size and density within a snowpack profile in the vertical direction.These heterogeneities produce great uncertainties to the snow depth or Snow Water Equivalent (SWE) retrieval from passive microwave data,as well as the validation of the results.In this study,we illustrate and discuss these problems based on the field observations of snow microwave radiation characteristics,the comparison of different snow remote sensing products and the modeling of snowpack radiation transfer characteristics,which will provide reference for the algorithm development of microwave remote sensing of snow and result analysis and validation.