No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Dependence of microwave radiative transfer process in a snow layer on thickness and density
Abstract
This work discusses the effect of the density gradient on the surface brightness temperature and elementary radiative processes in a snow layer in terms of absorption and backscattering coefficients. A gradient is created in a snow layer with the lapse of time and increases with snow depth. The two coefficients in a snow layer with a density gradient are estimated from observed coefficients of a fresh and shallow snow layer without a density gradient, assuming that the coefficients, i.e., absorption and backscattering cross-sections, increase proportionally with density. This paper points out that the increase in density affects the surface brightness temperature and the five elementary radiative transfer processes in the snow layer more significantly at lower frequencies. This paper also found that the surface brightness temperatures of snow were likely to have the same asymptotic value at greater depths from comparison between satellite observations in Alaska and a theoretical estimation using the above two coefficients modified by the density gradient. Copyright ©2007 by The International Society of Offshore and Polar Engineers(ISOPE).
ResearchGate has not been able to resolve any citations for this publication.
First results from a recently developed surface sensor for measuring the dielectric constant of snow at about 1 GHz are reported together with ground-based measurements of brightness temperatures between 4.9 and 94 GHz. The data are used to derive spectra of complex dielectric constants of wet snow for frequencies between 1 and 100 GHz. The result is simple: Debye relaxation spectra with a constant relaxation frequency of 9 GHz appear in contradiction to the mixing formula of Polder and van Santen. A way of resolving this discrepancy is presented.