Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery
Antarctic ice velocity maps describe the ice flow dynamics of the ice sheet and are one of the primary components used to estimate the Antarctic mass balance and contribution to global sea level changes. In comparison to velocity maps derived from recent satellite images of monthly to weekly time sp...
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Copernicus Publications
2022
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ftdoajarticles:oai:doaj.org/article:cabf7f96df8c433296eb9f695e649ba4 2023-05-15T13:38:48+02:00 Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery R. Li Y. Cheng H. Cui M. Xia X. Yuan Z. Li S. Luo G. Qiao 2022-03-01T00:00:00Z https://doi.org/10.5194/tc-16-737-2022 https://doaj.org/article/cabf7f96df8c433296eb9f695e649ba4 EN eng Copernicus Publications https://tc.copernicus.org/articles/16/737/2022/tc-16-737-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-737-2022 1994-0416 1994-0424 https://doaj.org/article/cabf7f96df8c433296eb9f695e649ba4 The Cryosphere, Vol 16, Pp 737-760 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-737-2022 2022-12-31T00:45:42Z Antarctic ice velocity maps describe the ice flow dynamics of the ice sheet and are one of the primary components used to estimate the Antarctic mass balance and contribution to global sea level changes. In comparison to velocity maps derived from recent satellite images of monthly to weekly time spans, historical maps, from before the 1990s, generally cover longer time spans, e.g., over 10 years, due to the scarce spatial and temporal coverage of earlier satellite image data. We found velocity overestimations (OEs) in such long-span maps that can be mainly attributed to velocity gradients and time span of the images used. In general, they are less significant in slow-flowing grounded regions with low spatial accelerations. Instead, they take effect in places of high ice dynamics, for example, near grounding lines and often in ice shelf fronts. Velocities in these areas are important for estimating ice sheet mass balance and analyzing ice shelf instability. We propose an innovative Lagrangian velocity-based method for OE correction without the use of field observations or additional image data. The method is validated by using a set of ground truth velocity maps for the Totten Glacier and Pine Island Glacier which are produced from high-quality Landsat 8 images from 2013 to 2020. Subsequently, the validated method is applied to a historical velocity map of the David Glacier region from images from 1972–1989 acquired during Landsat 1, 4, and 5 satellite missions. It is demonstrated that velocity overestimations of up to 39 m a −1 for David Glacier and 195 m a −1 for Pine Island Glacier can be effectively corrected. Furthermore, temporal acceleration information, e.g., on basal melting and calving activities, is preserved in the corrected velocity maps and can be used for long-term ice flow dynamics analysis. Our experiment results in the Pine Island Glacier (PIG) show that OEs of a 15-year span can reach up to 1300 m a −1 along the grounding line and cause an overestimated grounding line (GL) flux of 11.5 Gt a −1 ... Article in Journal/Newspaper Antarc* Antarctic David Glacier Ice Sheet Ice Shelf Pine Island Glacier The Cryosphere Totten Glacier Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Totten Glacier ENVELOPE(116.333,116.333,-66.833,-66.833) David Glacier ENVELOPE(160.000,160.000,-75.333,-75.333) The Cryosphere 16 2 737 760 |
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. Li Y. Cheng H. Cui M. Xia X. Yuan Z. Li S. Luo G. Qiao Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Antarctic ice velocity maps describe the ice flow dynamics of the ice sheet and are one of the primary components used to estimate the Antarctic mass balance and contribution to global sea level changes. In comparison to velocity maps derived from recent satellite images of monthly to weekly time spans, historical maps, from before the 1990s, generally cover longer time spans, e.g., over 10 years, due to the scarce spatial and temporal coverage of earlier satellite image data. We found velocity overestimations (OEs) in such long-span maps that can be mainly attributed to velocity gradients and time span of the images used. In general, they are less significant in slow-flowing grounded regions with low spatial accelerations. Instead, they take effect in places of high ice dynamics, for example, near grounding lines and often in ice shelf fronts. Velocities in these areas are important for estimating ice sheet mass balance and analyzing ice shelf instability. We propose an innovative Lagrangian velocity-based method for OE correction without the use of field observations or additional image data. The method is validated by using a set of ground truth velocity maps for the Totten Glacier and Pine Island Glacier which are produced from high-quality Landsat 8 images from 2013 to 2020. Subsequently, the validated method is applied to a historical velocity map of the David Glacier region from images from 1972–1989 acquired during Landsat 1, 4, and 5 satellite missions. It is demonstrated that velocity overestimations of up to 39 m a −1 for David Glacier and 195 m a −1 for Pine Island Glacier can be effectively corrected. Furthermore, temporal acceleration information, e.g., on basal melting and calving activities, is preserved in the corrected velocity maps and can be used for long-term ice flow dynamics analysis. Our experiment results in the Pine Island Glacier (PIG) show that OEs of a 15-year span can reach up to 1300 m a −1 along the grounding line and cause an overestimated grounding line (GL) flux of 11.5 Gt a −1 ... |
format |
Article in Journal/Newspaper |
author |
R. Li Y. Cheng H. Cui M. Xia X. Yuan Z. Li S. Luo G. Qiao |
author_facet |
R. Li Y. Cheng H. Cui M. Xia X. Yuan Z. Li S. Luo G. Qiao |
author_sort |
R. Li |
title |
Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
title_short |
Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
title_full |
Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
title_fullStr |
Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
title_full_unstemmed |
Overestimation and adjustment of Antarctic ice flow velocity fields reconstructed from historical satellite imagery |
title_sort |
overestimation and adjustment of antarctic ice flow velocity fields reconstructed from historical satellite imagery |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-737-2022 https://doaj.org/article/cabf7f96df8c433296eb9f695e649ba4 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(116.333,116.333,-66.833,-66.833) ENVELOPE(160.000,160.000,-75.333,-75.333) |
geographic |
Antarctic The Antarctic Pine Island Glacier Totten Glacier David Glacier |
geographic_facet |
Antarctic The Antarctic Pine Island Glacier Totten Glacier David Glacier |
genre |
Antarc* Antarctic David Glacier Ice Sheet Ice Shelf Pine Island Glacier The Cryosphere Totten Glacier |
genre_facet |
Antarc* Antarctic David Glacier Ice Sheet Ice Shelf Pine Island Glacier The Cryosphere Totten Glacier |
op_source |
The Cryosphere, Vol 16, Pp 737-760 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/737/2022/tc-16-737-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-737-2022 1994-0416 1994-0424 https://doaj.org/article/cabf7f96df8c433296eb9f695e649ba4 |
op_doi |
https://doi.org/10.5194/tc-16-737-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
2 |
container_start_page |
737 |
op_container_end_page |
760 |
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1766111201703493632 |