Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica
Space-borne passive microwave radiometers are widely used to retrieve information in snowy regions by exploiting the high sensitivity of microwave emission to snow properties. For the Antarctic Plateau, many studies presenting retrieval algorithms or numerical simulations have assumed, explicitly or...
Published in: | The Cryosphere |
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2014
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00019656 2023-05-15T13:41:02+02:00 Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica Picard, G. Royer, A. Arnaud, L. Fily, M. 2014-06 electronic https://doi.org/10.5194/tc-8-1105-2014 https://noa.gwlb.de/receive/cop_mods_00019656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019611/tc-8-1105-2014.pdf https://tc.copernicus.org/articles/8/1105/2014/tc-8-1105-2014.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-8-1105-2014 https://noa.gwlb.de/receive/cop_mods_00019656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019611/tc-8-1105-2014.pdf https://tc.copernicus.org/articles/8/1105/2014/tc-8-1105-2014.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2014 ftnonlinearchiv https://doi.org/10.5194/tc-8-1105-2014 2022-02-08T22:52:33Z Space-borne passive microwave radiometers are widely used to retrieve information in snowy regions by exploiting the high sensitivity of microwave emission to snow properties. For the Antarctic Plateau, many studies presenting retrieval algorithms or numerical simulations have assumed, explicitly or not, that the subpixel-scale heterogeneity is negligible and that the retrieved properties were representative of whole pixels. In this paper, we investigate the spatial variations of brightness temperature over a range of a few kilometers in the Dome C area. Using ground-based radiometers towed by a vehicle, we collected brightness temperature at 11, 19 and 37 GHz at horizontal and vertical polarizations along transects with meter resolution. The most remarkable observation was a series of regular undulations of the signal with a significant amplitude reaching 10 K at 37 GHz and a quasi-period of 30–50 m. In contrast, the variability at longer length scales seemed to be weak in the investigated area, and the mean brightness temperature was close to SSM/I and WindSat satellite observations for all the frequencies and polarizations. To establish a link between the snow characteristics and the microwave emission undulations, we collected detailed snow grain size and density profiles at two points where opposite extrema of brightness temperature were observed. Numerical simulations with the DMRT-ML microwave emission model revealed that the difference in density in the upper first meter explained most of the brightness temperature variations. In addition, we found that these variations of density near the surface were linked to snow hardness. Patches of hard snow – probably formed by wind compaction – were clearly visible and covered as much as 39% of the investigated area. Their brightness temperature was higher than in normal areas. This result implies that the microwave emission measured by satellites over Dome C is more complex than expected and very likely depends on the year-to-year areal proportion of the two different types of snow. Article in Journal/Newspaper Antarc* Antarctic Antarctica The Cryosphere Niedersächsisches Online-Archiv NOA Antarctic The Antarctic The Cryosphere 8 3 1105 1119 |
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Niedersächsisches Online-Archiv NOA |
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language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Picard, G. Royer, A. Arnaud, L. Fily, M. Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
topic_facet |
article Verlagsveröffentlichung |
description |
Space-borne passive microwave radiometers are widely used to retrieve information in snowy regions by exploiting the high sensitivity of microwave emission to snow properties. For the Antarctic Plateau, many studies presenting retrieval algorithms or numerical simulations have assumed, explicitly or not, that the subpixel-scale heterogeneity is negligible and that the retrieved properties were representative of whole pixels. In this paper, we investigate the spatial variations of brightness temperature over a range of a few kilometers in the Dome C area. Using ground-based radiometers towed by a vehicle, we collected brightness temperature at 11, 19 and 37 GHz at horizontal and vertical polarizations along transects with meter resolution. The most remarkable observation was a series of regular undulations of the signal with a significant amplitude reaching 10 K at 37 GHz and a quasi-period of 30–50 m. In contrast, the variability at longer length scales seemed to be weak in the investigated area, and the mean brightness temperature was close to SSM/I and WindSat satellite observations for all the frequencies and polarizations. To establish a link between the snow characteristics and the microwave emission undulations, we collected detailed snow grain size and density profiles at two points where opposite extrema of brightness temperature were observed. Numerical simulations with the DMRT-ML microwave emission model revealed that the difference in density in the upper first meter explained most of the brightness temperature variations. In addition, we found that these variations of density near the surface were linked to snow hardness. Patches of hard snow – probably formed by wind compaction – were clearly visible and covered as much as 39% of the investigated area. Their brightness temperature was higher than in normal areas. This result implies that the microwave emission measured by satellites over Dome C is more complex than expected and very likely depends on the year-to-year areal proportion of the two different types of snow. |
format |
Article in Journal/Newspaper |
author |
Picard, G. Royer, A. Arnaud, L. Fily, M. |
author_facet |
Picard, G. Royer, A. Arnaud, L. Fily, M. |
author_sort |
Picard, G. |
title |
Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
title_short |
Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
title_full |
Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
title_fullStr |
Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
title_full_unstemmed |
Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica |
title_sort |
influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around dome c in antarctica |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/tc-8-1105-2014 https://noa.gwlb.de/receive/cop_mods_00019656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019611/tc-8-1105-2014.pdf https://tc.copernicus.org/articles/8/1105/2014/tc-8-1105-2014.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica 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-8-1105-2014 https://noa.gwlb.de/receive/cop_mods_00019656 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00019611/tc-8-1105-2014.pdf https://tc.copernicus.org/articles/8/1105/2014/tc-8-1105-2014.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-8-1105-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
3 |
container_start_page |
1105 |
op_container_end_page |
1119 |
_version_ |
1766144851898793984 |