Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica
Using in situ data from 2011 and 2013, we evaluate the ability of CryoSat-2 (CS-2) to retrieve sea-ice freeboard over fast ice in McMurdo Sound. This provides the first systematic validation of CS-2 in the coastal Antarctic and offers insight into the assumptions currently used to process CS-2 data....
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Online Access: | https://epic.awi.de/id/eprint/37663/ https://hdl.handle.net/10013/epic.45308 |
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ftawi:oai:epic.awi.de:37663 2024-09-15T17:40:56+00:00 Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica Price, D. Beckers, Justin M. Ricker, Robert Kurtz, Nathan Rack, Wolfgang Haas, Christian Helm, Veit Hendricks, Stefan Leonard, G. Langhorn, P. 2015 https://epic.awi.de/id/eprint/37663/ https://hdl.handle.net/10013/epic.45308 unknown INT GLACIOL SOC Price, D. , Beckers, J. M. , Ricker, R. orcid:0000-0001-6928-7757 , Kurtz, N. , Rack, W. , Haas, C. , Helm, V. orcid:0000-0001-7788-9328 , Hendricks, S. orcid:0000-0002-1412-3146 , Leonard, G. and Langhorn, P. , Gateway Antarctica, University of Canterbury, Christchurch, New Zealand, Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA, Department of Earth, Space Science and Engineering, York University, Toronto, Ontario, Canada, School of Surveying, University of Otago, Dunedin, New Zealand, Department of Physics, University of Otago, Dunedin, New Zealand (2015) Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica , Journal of Glaciology, 61 (226), pp. 285-300 . doi:10.3189/2015JoG14J157 <https://doi.org/10.3189/2015JoG14J157> , hdl:10013/epic.45308 EPIC3Journal of Glaciology, INT GLACIOL SOC, 61(226), pp. 285-300, ISSN: 0022-1430 Article isiRev 2015 ftawi 2024-06-24T04:11:05Z Using in situ data from 2011 and 2013, we evaluate the ability of CryoSat-2 (CS-2) to retrieve sea-ice freeboard over fast ice in McMurdo Sound. This provides the first systematic validation of CS-2 in the coastal Antarctic and offers insight into the assumptions currently used to process CS-2 data. European Space Agency Level 2 (ESAL2) data are compared with results of a Waveform Fitting (WfF) procedure and a Threshold-First-Maximum-Retracker-Algorithm employed at 40% (TFMRA40). A supervised freeboard retrieval procedure is used to reduce errors associated with sea surface height identification and radar velocity in snow. We find ESAL2 freeboards located between the ice and snow freeboard rather than the frequently assumed snow/ice interface. WfF is within 0.04m of the ice freeboard but is influenced by variable snow conditions causing increased radar backscatter from the air/snow interface. Given such snow conditions and additional uncertainties in sea surface height identification, a positive bias of 0.14m away from the ice freeboard is observed. TFMRA40 freeboards are within 0.03m of the snow freeboard. The separation of freeboard estimates is primarily driven by the different assumptions of each retracker, although waveform alteration by variations in snow properties and surface roughness is evident. Techniques are amended where necessary, and automatic freeboard retrieval procedures for ESAL2, WfF and TFMRA40 are presented. CS-2 detects annual fastice freeboard trends using all three automatic procedures that are in line with known sea-ice growth rates in the region. Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarctica Journal Journal of Glaciology McMurdo Sound Sea ice Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Journal of Glaciology 61 226 285 300 |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
Using in situ data from 2011 and 2013, we evaluate the ability of CryoSat-2 (CS-2) to retrieve sea-ice freeboard over fast ice in McMurdo Sound. This provides the first systematic validation of CS-2 in the coastal Antarctic and offers insight into the assumptions currently used to process CS-2 data. European Space Agency Level 2 (ESAL2) data are compared with results of a Waveform Fitting (WfF) procedure and a Threshold-First-Maximum-Retracker-Algorithm employed at 40% (TFMRA40). A supervised freeboard retrieval procedure is used to reduce errors associated with sea surface height identification and radar velocity in snow. We find ESAL2 freeboards located between the ice and snow freeboard rather than the frequently assumed snow/ice interface. WfF is within 0.04m of the ice freeboard but is influenced by variable snow conditions causing increased radar backscatter from the air/snow interface. Given such snow conditions and additional uncertainties in sea surface height identification, a positive bias of 0.14m away from the ice freeboard is observed. TFMRA40 freeboards are within 0.03m of the snow freeboard. The separation of freeboard estimates is primarily driven by the different assumptions of each retracker, although waveform alteration by variations in snow properties and surface roughness is evident. Techniques are amended where necessary, and automatic freeboard retrieval procedures for ESAL2, WfF and TFMRA40 are presented. CS-2 detects annual fastice freeboard trends using all three automatic procedures that are in line with known sea-ice growth rates in the region. |
format |
Article in Journal/Newspaper |
author |
Price, D. Beckers, Justin M. Ricker, Robert Kurtz, Nathan Rack, Wolfgang Haas, Christian Helm, Veit Hendricks, Stefan Leonard, G. Langhorn, P. |
spellingShingle |
Price, D. Beckers, Justin M. Ricker, Robert Kurtz, Nathan Rack, Wolfgang Haas, Christian Helm, Veit Hendricks, Stefan Leonard, G. Langhorn, P. Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
author_facet |
Price, D. Beckers, Justin M. Ricker, Robert Kurtz, Nathan Rack, Wolfgang Haas, Christian Helm, Veit Hendricks, Stefan Leonard, G. Langhorn, P. |
author_sort |
Price, D. |
title |
Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
title_short |
Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
title_full |
Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
title_fullStr |
Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
title_full_unstemmed |
Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica |
title_sort |
evaluation of cryosat-2 derived sea-ice freeboard over fast ice in mcmurdo sound, antarctica |
publisher |
INT GLACIOL SOC |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/37663/ https://hdl.handle.net/10013/epic.45308 |
genre |
Antarc* Antarctic Antarctica Antarctica Journal Journal of Glaciology McMurdo Sound Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Antarctica Journal Journal of Glaciology McMurdo Sound Sea ice |
op_source |
EPIC3Journal of Glaciology, INT GLACIOL SOC, 61(226), pp. 285-300, ISSN: 0022-1430 |
op_relation |
Price, D. , Beckers, J. M. , Ricker, R. orcid:0000-0001-6928-7757 , Kurtz, N. , Rack, W. , Haas, C. , Helm, V. orcid:0000-0001-7788-9328 , Hendricks, S. orcid:0000-0002-1412-3146 , Leonard, G. and Langhorn, P. , Gateway Antarctica, University of Canterbury, Christchurch, New Zealand, Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA, Department of Earth, Space Science and Engineering, York University, Toronto, Ontario, Canada, School of Surveying, University of Otago, Dunedin, New Zealand, Department of Physics, University of Otago, Dunedin, New Zealand (2015) Evaluation of CryoSat-2 derived sea-ice freeboard over fast ice in McMurdo Sound, Antarctica , Journal of Glaciology, 61 (226), pp. 285-300 . doi:10.3189/2015JoG14J157 <https://doi.org/10.3189/2015JoG14J157> , hdl:10013/epic.45308 |
container_title |
Journal of Glaciology |
container_volume |
61 |
container_issue |
226 |
container_start_page |
285 |
op_container_end_page |
300 |
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1810486995630161920 |