Parameterization of single-scattering properties of snow
Snow consists of non-spherical grains of various shapes and sizes. Still, in many radiative transfer applications, single-scattering properties of snow have been based on the assumption of spherical grains. More recently, second-generation Koch fractals have been employed. While they produce a relat...
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Copernicus Publications
2015
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00016099 2023-05-15T17:48:28+02:00 Parameterization of single-scattering properties of snow Räisänen, P. Kokhanovsky, A. Guyot, G. Jourdan, O. Nousiainen, T. 2015-06 electronic https://doi.org/10.5194/tc-9-1277-2015 https://noa.gwlb.de/receive/cop_mods_00016099 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016054/tc-9-1277-2015.pdf https://tc.copernicus.org/articles/9/1277/2015/tc-9-1277-2015.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-9-1277-2015 https://noa.gwlb.de/receive/cop_mods_00016099 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016054/tc-9-1277-2015.pdf https://tc.copernicus.org/articles/9/1277/2015/tc-9-1277-2015.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2015 ftnonlinearchiv https://doi.org/10.5194/tc-9-1277-2015 2022-02-08T22:54:17Z Snow consists of non-spherical grains of various shapes and sizes. Still, in many radiative transfer applications, single-scattering properties of snow have been based on the assumption of spherical grains. More recently, second-generation Koch fractals have been employed. While they produce a relatively flat phase function typical of deformed non-spherical particles, this is still a rather ad hoc choice. Here, angular scattering measurements for blowing snow conducted during the CLimate IMpacts of Short-Lived pollutants In the Polar region (CLIMSLIP) campaign at Ny Ålesund, Svalbard, are used to construct a reference phase function for snow. Based on this phase function, an optimized habit combination (OHC) consisting of severely rough (SR) droxtals, aggregates of SR plates and strongly distorted Koch fractals is selected. The single-scattering properties of snow are then computed for the OHC as a function of wavelength λ and snow grain volume-to-projected area equivalent radius rvp. Parameterization equations are developed for λ = 0.199–2.7 μm and rvp = 10–2000 μm, which express the single-scattering co-albedo β, the asymmetry parameter g and the phase function P11 as functions of the size parameter and the real and imaginary parts of the refractive index. The parameterizations are analytic and simple to use in radiative transfer models. Compared to the reference values computed for the OHC, the accuracy of the parameterization is very high for β and g. This is also true for the phase function parameterization, except for strongly absorbing cases (β > 0.3). Finally, we consider snow albedo and reflected radiances for the suggested snow optics parameterization, making comparisons to spheres and distorted Koch fractals. Article in Journal/Newspaper Ny Ålesund Ny-Ålesund Svalbard The Cryosphere Niedersächsisches Online-Archiv NOA Ny-Ålesund Svalbard The Cryosphere 9 3 1277 1301 |
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English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Räisänen, P. Kokhanovsky, A. Guyot, G. Jourdan, O. Nousiainen, T. Parameterization of single-scattering properties of snow |
topic_facet |
article Verlagsveröffentlichung |
description |
Snow consists of non-spherical grains of various shapes and sizes. Still, in many radiative transfer applications, single-scattering properties of snow have been based on the assumption of spherical grains. More recently, second-generation Koch fractals have been employed. While they produce a relatively flat phase function typical of deformed non-spherical particles, this is still a rather ad hoc choice. Here, angular scattering measurements for blowing snow conducted during the CLimate IMpacts of Short-Lived pollutants In the Polar region (CLIMSLIP) campaign at Ny Ålesund, Svalbard, are used to construct a reference phase function for snow. Based on this phase function, an optimized habit combination (OHC) consisting of severely rough (SR) droxtals, aggregates of SR plates and strongly distorted Koch fractals is selected. The single-scattering properties of snow are then computed for the OHC as a function of wavelength λ and snow grain volume-to-projected area equivalent radius rvp. Parameterization equations are developed for λ = 0.199–2.7 μm and rvp = 10–2000 μm, which express the single-scattering co-albedo β, the asymmetry parameter g and the phase function P11 as functions of the size parameter and the real and imaginary parts of the refractive index. The parameterizations are analytic and simple to use in radiative transfer models. Compared to the reference values computed for the OHC, the accuracy of the parameterization is very high for β and g. This is also true for the phase function parameterization, except for strongly absorbing cases (β > 0.3). Finally, we consider snow albedo and reflected radiances for the suggested snow optics parameterization, making comparisons to spheres and distorted Koch fractals. |
format |
Article in Journal/Newspaper |
author |
Räisänen, P. Kokhanovsky, A. Guyot, G. Jourdan, O. Nousiainen, T. |
author_facet |
Räisänen, P. Kokhanovsky, A. Guyot, G. Jourdan, O. Nousiainen, T. |
author_sort |
Räisänen, P. |
title |
Parameterization of single-scattering properties of snow |
title_short |
Parameterization of single-scattering properties of snow |
title_full |
Parameterization of single-scattering properties of snow |
title_fullStr |
Parameterization of single-scattering properties of snow |
title_full_unstemmed |
Parameterization of single-scattering properties of snow |
title_sort |
parameterization of single-scattering properties of snow |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/tc-9-1277-2015 https://noa.gwlb.de/receive/cop_mods_00016099 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016054/tc-9-1277-2015.pdf https://tc.copernicus.org/articles/9/1277/2015/tc-9-1277-2015.pdf |
geographic |
Ny-Ålesund Svalbard |
geographic_facet |
Ny-Ålesund Svalbard |
genre |
Ny Ålesund Ny-Ålesund Svalbard The Cryosphere |
genre_facet |
Ny Ålesund Ny-Ålesund Svalbard The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-9-1277-2015 https://noa.gwlb.de/receive/cop_mods_00016099 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00016054/tc-9-1277-2015.pdf https://tc.copernicus.org/articles/9/1277/2015/tc-9-1277-2015.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-9-1277-2015 |
container_title |
The Cryosphere |
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9 |
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3 |
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1277 |
op_container_end_page |
1301 |
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