Retrieval of snow albedo and grain size using reflectance measurements in Himalayan basin
Retrieval of snow albedo and grain size using reflectance measurements in Himalayan basin
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DOI：
10.5194/tc-5-203-2011
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发表时间：
2010-11
期刊：
影响因子：
--
通讯作者：
H. S. Negi;A. Kokhanovsky
中科院分区：
文献类型：
--
作者：
H. S. Negi;A. Kokhanovsky
抽象的。本文对喜马拉雅季节性雪进行了光谱反射率测量和分析，以反演雪的反照率和有效粒径。应用渐近辐射传递（ART）理论来反演平面和球面反照率。将检索到的平面反照率与测量的光谱反照率进行比较，观察到具有±10%差异的良好一致性。发现检索到的积分反照率与地面观测的宽带反照率的差异在±6%以内。对不同雪类型使用基于 ART 理论的不同模型反演的雪粒尺寸进行了比较，发现使用双通道方法（一个在可见光区域，另一个在近红外区域）的雪粒尺寸模型可以很好地适用于喜马拉雅季节性雪，并且发现与雪粒尺寸的时间变化一致。这种方法对于喜马拉雅山上部的干净、干燥的雪非常有效，但有时，由于反射率较低（
Abstract. In the present paper, spectral reflectance measurements of Himalayan seasonal snow were carried out and analysed to retrieve the snow albedo and effective grain size. The asymptotic radiative transfer (ART) theory was applied to retrieve the plane and spherical albedo. The retrieved plane albedo was compared with the measured spectral albedo and a good agreement was observed with ±10% differences. Retrieved integrated albedo was found within ±6% difference with ground observed broadband albedo. The retrieved snow grain sizes using different models based on the ART theory were compared for various snow types and it was observed that the grain size model using two channel method (one in visible and another in NIR region) can work well for the Himalayan seasonal snow and it was found consistent with temporal changes in grain size. This method can work very well for clean, dry snow as in the upper Himalaya, but sometimes, due to the low reflectances (