Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice
Owing to differing and complex snow geophysical properties, radar waves of different wavelengths undergo variable penetration through snow-covered sea ice. However, the mechanisms influencing radar altimeter backscatter from snow-covered sea ice, especially at Ka- and Ku-band frequencies, and the im...
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2021
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Online Access: | https://doi.org/10.5194/tc-15-1811-2021 https://doaj.org/article/21b3d8b0924c4062bd14c1d88850ab39 |
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ftdoajarticles:oai:doaj.org/article:21b3d8b0924c4062bd14c1d88850ab39 2023-05-15T15:03:45+02:00 Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice R. T. Tonboe V. Nandan J. Yackel S. Kern L. T. Pedersen J. Stroeve 2021-04-01T00:00:00Z https://doi.org/10.5194/tc-15-1811-2021 https://doaj.org/article/21b3d8b0924c4062bd14c1d88850ab39 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/1811/2021/tc-15-1811-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-1811-2021 1994-0416 1994-0424 https://doaj.org/article/21b3d8b0924c4062bd14c1d88850ab39 The Cryosphere, Vol 15, Pp 1811-1822 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-1811-2021 2022-12-31T09:44:44Z Owing to differing and complex snow geophysical properties, radar waves of different wavelengths undergo variable penetration through snow-covered sea ice. However, the mechanisms influencing radar altimeter backscatter from snow-covered sea ice, especially at Ka- and Ku-band frequencies, and the impact on the Ka- and Ku-band radar scattering horizon or the “track point” (i.e. the scattering layer depth detected by the radar re-tracker) are not well understood. In this study, we evaluate the Ka- and Ku-band radar scattering horizon with respect to radar penetration and ice floe buoyancy using a first-order scattering model and the Archimedes principle. The scattering model is forced with snow depth data from the European Space Agency (ESA) climate change initiative (CCI) round-robin data package, in which NASA's Operation IceBridge (OIB) data and climatology are included, and detailed snow geophysical property profiles from the Canadian Arctic. Our simulations demonstrate that the Ka- and Ku-band track point difference is a function of snow depth; however, the simulated track point difference is much smaller than what is reported in the literature from the Ku-band CryoSat-2 and Ka-band SARAL/AltiKa satellite radar altimeter observations. We argue that this discrepancy in the Ka- and Ku-band track point differences is sensitive to ice type and snow depth and its associated geophysical properties. Snow salinity is first increasing the Ka- and Ku-band track point difference when the snow is thin and then decreasing the difference when the snow is thick ( >0.1 m). A relationship between the Ku-band radar scattering horizon and snow depth is found. This relationship has implications for (1) the use of snow climatology in the conversion of radar freeboard into sea ice thickness and (2) the impact of variability in measured snow depth on the derived ice thickness. For both (1) and (2), the impact of using a snow climatology versus the actual snow depth is relatively small on the radar freeboard, only raising the ... Article in Journal/Newspaper Arctic Climate change Sea ice The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic The Cryosphere 15 4 1811 1822 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 R. T. Tonboe V. Nandan J. Yackel S. Kern L. T. Pedersen J. Stroeve Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Owing to differing and complex snow geophysical properties, radar waves of different wavelengths undergo variable penetration through snow-covered sea ice. However, the mechanisms influencing radar altimeter backscatter from snow-covered sea ice, especially at Ka- and Ku-band frequencies, and the impact on the Ka- and Ku-band radar scattering horizon or the “track point” (i.e. the scattering layer depth detected by the radar re-tracker) are not well understood. In this study, we evaluate the Ka- and Ku-band radar scattering horizon with respect to radar penetration and ice floe buoyancy using a first-order scattering model and the Archimedes principle. The scattering model is forced with snow depth data from the European Space Agency (ESA) climate change initiative (CCI) round-robin data package, in which NASA's Operation IceBridge (OIB) data and climatology are included, and detailed snow geophysical property profiles from the Canadian Arctic. Our simulations demonstrate that the Ka- and Ku-band track point difference is a function of snow depth; however, the simulated track point difference is much smaller than what is reported in the literature from the Ku-band CryoSat-2 and Ka-band SARAL/AltiKa satellite radar altimeter observations. We argue that this discrepancy in the Ka- and Ku-band track point differences is sensitive to ice type and snow depth and its associated geophysical properties. Snow salinity is first increasing the Ka- and Ku-band track point difference when the snow is thin and then decreasing the difference when the snow is thick ( >0.1 m). A relationship between the Ku-band radar scattering horizon and snow depth is found. This relationship has implications for (1) the use of snow climatology in the conversion of radar freeboard into sea ice thickness and (2) the impact of variability in measured snow depth on the derived ice thickness. For both (1) and (2), the impact of using a snow climatology versus the actual snow depth is relatively small on the radar freeboard, only raising the ... |
format |
Article in Journal/Newspaper |
author |
R. T. Tonboe V. Nandan J. Yackel S. Kern L. T. Pedersen J. Stroeve |
author_facet |
R. T. Tonboe V. Nandan J. Yackel S. Kern L. T. Pedersen J. Stroeve |
author_sort |
R. T. Tonboe |
title |
Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
title_short |
Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
title_full |
Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
title_fullStr |
Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
title_full_unstemmed |
Simulated Ka- and Ku-band radar altimeter height and freeboard estimation on snow-covered Arctic sea ice |
title_sort |
simulated ka- and ku-band radar altimeter height and freeboard estimation on snow-covered arctic sea ice |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-1811-2021 https://doaj.org/article/21b3d8b0924c4062bd14c1d88850ab39 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change Sea ice The Cryosphere |
genre_facet |
Arctic Climate change Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 1811-1822 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/1811/2021/tc-15-1811-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-1811-2021 1994-0416 1994-0424 https://doaj.org/article/21b3d8b0924c4062bd14c1d88850ab39 |
op_doi |
https://doi.org/10.5194/tc-15-1811-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
4 |
container_start_page |
1811 |
op_container_end_page |
1822 |
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1766335601228906496 |