Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band
Melt occurrence in Antarctica is derived from L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite between the austral summer 2010–2011 and 2017–2018. The detection algorithm is adapted from a threshold method previously developed for 19 GHz passive microwave measurements f...
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ftcopernicus:oai:publications.copernicus.org:tc79347 2023-05-15T13:55:28+02:00 Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band Leduc-Leballeur, Marion Picard, Ghislain Macelloni, Giovanni Mialon, Arnaud Kerr, Yann H. 2020-02-11 application/pdf https://doi.org/10.5194/tc-14-539-2020 https://tc.copernicus.org/articles/14/539/2020/ eng eng doi:10.5194/tc-14-539-2020 https://tc.copernicus.org/articles/14/539/2020/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-14-539-2020 2020-07-20T16:22:25Z Melt occurrence in Antarctica is derived from L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite between the austral summer 2010–2011 and 2017–2018. The detection algorithm is adapted from a threshold method previously developed for 19 GHz passive microwave measurements from the special sensor microwave imager (SSM/I) and special sensor microwave imager sounder (SSMIS). The comparison of daily melt occurrence retrieved from 1.4 and 19 GHz observations shows an overall close agreement, but a lag of few days is usually observed by SMOS at the beginning of the melt season. To understand the difference, a theoretical analysis is performed using a microwave emission radiative transfer model. It shows that the sensitivity of 1.4 GHz signal to liquid water is significantly weaker than at 19 GHz if the water is only present in the uppermost tens of centimetres of the snowpack. Conversely, 1.4 GHz measurements are sensitive to water when spread over at least 1 m and when present in depths up to hundreds of metres. This is explained by the large penetration depth in dry snow and by the long wavelength (21 cm). We conclude that SMOS and higher-frequency radiometers provide interesting complementary information on melt occurrence and on the location of the water in the snowpack. Text Antarc* Antarctica Copernicus Publications: E-Journals Austral The Cryosphere 14 2 539 548 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Melt occurrence in Antarctica is derived from L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite between the austral summer 2010–2011 and 2017–2018. The detection algorithm is adapted from a threshold method previously developed for 19 GHz passive microwave measurements from the special sensor microwave imager (SSM/I) and special sensor microwave imager sounder (SSMIS). The comparison of daily melt occurrence retrieved from 1.4 and 19 GHz observations shows an overall close agreement, but a lag of few days is usually observed by SMOS at the beginning of the melt season. To understand the difference, a theoretical analysis is performed using a microwave emission radiative transfer model. It shows that the sensitivity of 1.4 GHz signal to liquid water is significantly weaker than at 19 GHz if the water is only present in the uppermost tens of centimetres of the snowpack. Conversely, 1.4 GHz measurements are sensitive to water when spread over at least 1 m and when present in depths up to hundreds of metres. This is explained by the large penetration depth in dry snow and by the long wavelength (21 cm). We conclude that SMOS and higher-frequency radiometers provide interesting complementary information on melt occurrence and on the location of the water in the snowpack. |
format |
Text |
author |
Leduc-Leballeur, Marion Picard, Ghislain Macelloni, Giovanni Mialon, Arnaud Kerr, Yann H. |
spellingShingle |
Leduc-Leballeur, Marion Picard, Ghislain Macelloni, Giovanni Mialon, Arnaud Kerr, Yann H. Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
author_facet |
Leduc-Leballeur, Marion Picard, Ghislain Macelloni, Giovanni Mialon, Arnaud Kerr, Yann H. |
author_sort |
Leduc-Leballeur, Marion |
title |
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
title_short |
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
title_full |
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
title_fullStr |
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
title_full_unstemmed |
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band |
title_sort |
melt in antarctica derived from soil moisture and ocean salinity (smos) observations at l band |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-539-2020 https://tc.copernicus.org/articles/14/539/2020/ |
geographic |
Austral |
geographic_facet |
Austral |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-14-539-2020 https://tc.copernicus.org/articles/14/539/2020/ |
op_doi |
https://doi.org/10.5194/tc-14-539-2020 |
container_title |
The Cryosphere |
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14 |
container_issue |
2 |
container_start_page |
539 |
op_container_end_page |
548 |
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1766262099899580416 |