Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series
The snow microstructure, i.e., the spatial distribution of ice and pores, generally shows an anisotropy which is driven by gravity and temperature gradients and commonly determined from stereology or computer tomography. This structural anisotropy induces anisotropic mechanical, thermal, and dielect...
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ftcopernicus:oai:publications.copernicus.org:tc32662 2023-05-15T17:42:35+02:00 Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series Leinss, Silvan Löwe, Henning Proksch, Martin Lemmetyinen, Juha Wiesmann, Andreas Hajnsek, Irena 2018-09-27 application/pdf https://doi.org/10.5194/tc-10-1771-2016 https://tc.copernicus.org/articles/10/1771/2016/ eng eng doi:10.5194/tc-10-1771-2016 https://tc.copernicus.org/articles/10/1771/2016/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-10-1771-2016 2020-07-20T16:24:02Z The snow microstructure, i.e., the spatial distribution of ice and pores, generally shows an anisotropy which is driven by gravity and temperature gradients and commonly determined from stereology or computer tomography. This structural anisotropy induces anisotropic mechanical, thermal, and dielectric properties. We present a method based on radio-wave birefringence to determine the depth-averaged, dielectric anisotropy of seasonal snow with radar instruments from space, air, or ground. For known snow depth and density, the birefringence allows determination of the dielectric anisotropy by measuring the copolar phase difference (CPD) between linearly polarized microwaves propagating obliquely through the snowpack. The dielectric and structural anisotropy are linked by Maxwell–Garnett-type mixing formulas. The anisotropy evolution of a natural snowpack in Northern Finland was observed over four winters (2009–2013) with the ground-based radar instrument "SnowScat". The radar measurements indicate horizontal structures for fresh snow and vertical structures in old snow which is confirmed by computer tomographic in situ measurements. The temporal evolution of the CPD agreed in ground-based data compared to space-borne measurements from the satellite TerraSAR-X. The presented dataset provides a valuable basis for the development of new snow metamorphism models which include the anisotropy of the snow microstructure. Text Northern Finland Copernicus Publications: E-Journals The Cryosphere 10 4 1771 1797 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The snow microstructure, i.e., the spatial distribution of ice and pores, generally shows an anisotropy which is driven by gravity and temperature gradients and commonly determined from stereology or computer tomography. This structural anisotropy induces anisotropic mechanical, thermal, and dielectric properties. We present a method based on radio-wave birefringence to determine the depth-averaged, dielectric anisotropy of seasonal snow with radar instruments from space, air, or ground. For known snow depth and density, the birefringence allows determination of the dielectric anisotropy by measuring the copolar phase difference (CPD) between linearly polarized microwaves propagating obliquely through the snowpack. The dielectric and structural anisotropy are linked by Maxwell–Garnett-type mixing formulas. The anisotropy evolution of a natural snowpack in Northern Finland was observed over four winters (2009–2013) with the ground-based radar instrument "SnowScat". The radar measurements indicate horizontal structures for fresh snow and vertical structures in old snow which is confirmed by computer tomographic in situ measurements. The temporal evolution of the CPD agreed in ground-based data compared to space-borne measurements from the satellite TerraSAR-X. The presented dataset provides a valuable basis for the development of new snow metamorphism models which include the anisotropy of the snow microstructure. |
format |
Text |
author |
Leinss, Silvan Löwe, Henning Proksch, Martin Lemmetyinen, Juha Wiesmann, Andreas Hajnsek, Irena |
spellingShingle |
Leinss, Silvan Löwe, Henning Proksch, Martin Lemmetyinen, Juha Wiesmann, Andreas Hajnsek, Irena Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
author_facet |
Leinss, Silvan Löwe, Henning Proksch, Martin Lemmetyinen, Juha Wiesmann, Andreas Hajnsek, Irena |
author_sort |
Leinss, Silvan |
title |
Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
title_short |
Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
title_full |
Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
title_fullStr |
Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
title_full_unstemmed |
Anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
title_sort |
anisotropy of seasonal snow measured by polarimetric phase differences in radar time series |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-10-1771-2016 https://tc.copernicus.org/articles/10/1771/2016/ |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-10-1771-2016 https://tc.copernicus.org/articles/10/1771/2016/ |
op_doi |
https://doi.org/10.5194/tc-10-1771-2016 |
container_title |
The Cryosphere |
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10 |
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4 |
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1771 |
op_container_end_page |
1797 |
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1766144460799868928 |