The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions
Abstract Satellite observations of snow‐covered regions in the microwave range have the potential to retrieve essential climate variables such as snow height. This requires a precise understanding of how microwave scattering is linked to snow microstructural properties (density, grain size, grain sh...
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ftdoajarticles:oai:doaj.org/article:853d64dd45d9468d8e209c249b475eeb 2023-05-15T13:36:02+02:00 The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions G. Picard H. Löwe F. Domine L. Arnaud F. Larue V. Favier E. Le Meur E. Lefebvre J. Savarino A. Royer 2022-08-01T00:00:00Z https://doi.org/10.1029/2021AV000630 https://doaj.org/article/853d64dd45d9468d8e209c249b475eeb EN eng Wiley https://doi.org/10.1029/2021AV000630 https://doaj.org/toc/2576-604X 2576-604X doi:10.1029/2021AV000630 https://doaj.org/article/853d64dd45d9468d8e209c249b475eeb AGU Advances, Vol 3, Iss 4, Pp n/a-n/a (2022) snow remote sensing microwave porous media microstructure modeling Geology QE1-996.5 Geophysics. Cosmic physics QC801-809 article 2022 ftdoajarticles https://doi.org/10.1029/2021AV000630 2022-12-30T20:12:30Z Abstract Satellite observations of snow‐covered regions in the microwave range have the potential to retrieve essential climate variables such as snow height. This requires a precise understanding of how microwave scattering is linked to snow microstructural properties (density, grain size, grain shape and arrangement). This link has so far relied on empirical adjustments of the theories, precluding the development of robust retrieval algorithms. Here we solve this problem by introducing a new microstructural parameter able to consistently predict scattering. This “microwave grain size” is demonstrated to be proportional to the measurable optical grain size and to a new factor describing the chord length dispersion in the microstructure, a geometrical property known as polydispersity. By assuming that the polydispersity depends on the snow grain type only, we retrieve its value for rounded and faceted grains by optimization of microwave satellite observations in 18 Antarctic sites, and for depth hoar in 86 Canadian sites using ground‐based observations. The value for the convex grains (0.6) compares favorably to the polydispersity calculated from 3D micro‐computed tomography images for alpine grains, while values for depth hoar show wider variations (1.2–1.9) and are larger in Canada than in the Alps. Nevertheless, using one value for each grain type, the microwave observations in Antarctica and in Canada can be simulated from in‐situ measurements with good accuracy with a fully physical model. These findings improve snow scattering modeling, enabling future more accurate uses of satellite observations in snow hydrological and meteorological applications. Article in Journal/Newspaper Antarc* Antarctic Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Canada AGU Advances 3 4 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
snow remote sensing microwave porous media microstructure modeling Geology QE1-996.5 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
snow remote sensing microwave porous media microstructure modeling Geology QE1-996.5 Geophysics. Cosmic physics QC801-809 G. Picard H. Löwe F. Domine L. Arnaud F. Larue V. Favier E. Le Meur E. Lefebvre J. Savarino A. Royer The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
topic_facet |
snow remote sensing microwave porous media microstructure modeling Geology QE1-996.5 Geophysics. Cosmic physics QC801-809 |
description |
Abstract Satellite observations of snow‐covered regions in the microwave range have the potential to retrieve essential climate variables such as snow height. This requires a precise understanding of how microwave scattering is linked to snow microstructural properties (density, grain size, grain shape and arrangement). This link has so far relied on empirical adjustments of the theories, precluding the development of robust retrieval algorithms. Here we solve this problem by introducing a new microstructural parameter able to consistently predict scattering. This “microwave grain size” is demonstrated to be proportional to the measurable optical grain size and to a new factor describing the chord length dispersion in the microstructure, a geometrical property known as polydispersity. By assuming that the polydispersity depends on the snow grain type only, we retrieve its value for rounded and faceted grains by optimization of microwave satellite observations in 18 Antarctic sites, and for depth hoar in 86 Canadian sites using ground‐based observations. The value for the convex grains (0.6) compares favorably to the polydispersity calculated from 3D micro‐computed tomography images for alpine grains, while values for depth hoar show wider variations (1.2–1.9) and are larger in Canada than in the Alps. Nevertheless, using one value for each grain type, the microwave observations in Antarctica and in Canada can be simulated from in‐situ measurements with good accuracy with a fully physical model. These findings improve snow scattering modeling, enabling future more accurate uses of satellite observations in snow hydrological and meteorological applications. |
format |
Article in Journal/Newspaper |
author |
G. Picard H. Löwe F. Domine L. Arnaud F. Larue V. Favier E. Le Meur E. Lefebvre J. Savarino A. Royer |
author_facet |
G. Picard H. Löwe F. Domine L. Arnaud F. Larue V. Favier E. Le Meur E. Lefebvre J. Savarino A. Royer |
author_sort |
G. Picard |
title |
The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
title_short |
The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
title_full |
The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
title_fullStr |
The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
title_full_unstemmed |
The Microwave Snow Grain Size: A New Concept to Predict Satellite Observations Over Snow‐Covered Regions |
title_sort |
microwave snow grain size: a new concept to predict satellite observations over snow‐covered regions |
publisher |
Wiley |
publishDate |
2022 |
url |
https://doi.org/10.1029/2021AV000630 https://doaj.org/article/853d64dd45d9468d8e209c249b475eeb |
geographic |
Antarctic Canada |
geographic_facet |
Antarctic Canada |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
AGU Advances, Vol 3, Iss 4, Pp n/a-n/a (2022) |
op_relation |
https://doi.org/10.1029/2021AV000630 https://doaj.org/toc/2576-604X 2576-604X doi:10.1029/2021AV000630 https://doaj.org/article/853d64dd45d9468d8e209c249b475eeb |
op_doi |
https://doi.org/10.1029/2021AV000630 |
container_title |
AGU Advances |
container_volume |
3 |
container_issue |
4 |
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1766073593531203584 |