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Evaluating Multispectral Snowpack Reflectivity With Changing Snow Correlation LengthsThis study investigates the sensitivity of multispectral reflectivity to changing snow correlation lengths. Matzler's ice-lamellae radiative transfer model was implemented and tested to evaluate the reflectivity of snow correlation lengths at multiple frequencies from the ultraviolet (UV) to the microwave bands. The model reveals that, in the UV to infrared (IR) frequency range, the reflectivity and correlation length are inversely related, whereas reflectivity increases with snow correlation length in the microwave frequency range. The model further shows that the reflectivity behavior can be mainly attributed to scattering rather than absorption for shallow snowpacks. The largest scattering coefficients and reflectivity occur at very small correlation lengths (approximately 10(exp -5 m) for frequencies higher than the IR band. In the microwave range, the largest scattering coefficients are found at millimeter wavelengths. For validation purposes, the ice-lamella model is coupled with a multilayer snow physics model to characterize the reflectivity response of realistic snow hydrological processes. The evolution of the coupled model simulated reflectivities in both the visible and the microwave bands is consistent with satellite-based reflectivity observations in the same frequencies. The model results are also compared with colocated in situ snow correlation length measurements (Cold Land Processes Field Experiment 2002-2003). The analysis and evaluation of model results indicate that the coupled multifrequency radiative transfer and snow hydrology modeling system can be used as a forward operator in a data-assimilation framework to predict the status of snow physical properties, including snow correlation length.
Document ID
20170003729
Document Type
Reprint (Version printed in journal)
Authors
Kang, Do Hyuk (Maryland Univ. Greenbelt, MD, United States)
Barros, Ana P. (Duke Univ. Durham, NC, United States)
Kim, Edward J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
April 20, 2017
Publication Date
September 20, 2016
Publication Information
Publication: IEEE Transactions on Geoscience and Remote Sensing
Volume: 54
Issue: 12
ISSN: 0196-2892
Subject Category
Earth Resources and Remote Sensing
Report/Patent Number
GSFC-E-DAA-TN41700
Funding Number(s)
CONTRACT_GRANT: NNX13AH39G
CONTRACT_GRANT: NNX17AE79A
Distribution Limits
Public
Copyright
Other