Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf
One of the last remaining floating tongues of the Greenland ice sheet (GrIS), the Petermann Glacier ice shelf (PGIS), is seasonally shielded from warm Atlantic water (AW) by the formation of sea ice arches in the Nares Strait. However, continued decline of the Arctic sea ice extent and thickness sug...
Published in: | The Cryosphere |
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Language: | English |
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Copernicus Publications
2023
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Online Access: | https://doi.org/10.5194/tc-17-5255-2023 https://doaj.org/article/bd3c54bed3f7401fa1a5807458244441 |
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ftdoajarticles:oai:doaj.org/article:bd3c54bed3f7401fa1a5807458244441 2024-01-14T10:05:11+01:00 Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf A. Prakash Q. Zhou T. Hattermann N. Kirchner 2023-12-01T00:00:00Z https://doi.org/10.5194/tc-17-5255-2023 https://doaj.org/article/bd3c54bed3f7401fa1a5807458244441 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/5255/2023/tc-17-5255-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-5255-2023 1994-0416 1994-0424 https://doaj.org/article/bd3c54bed3f7401fa1a5807458244441 The Cryosphere, Vol 17, Pp 5255-5281 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-5255-2023 2023-12-17T01:44:08Z One of the last remaining floating tongues of the Greenland ice sheet (GrIS), the Petermann Glacier ice shelf (PGIS), is seasonally shielded from warm Atlantic water (AW) by the formation of sea ice arches in the Nares Strait. However, continued decline of the Arctic sea ice extent and thickness suggests that arch formation is likely to become anomalous, necessitating an investigation into the response of PGIS to a year-round mobile and thin sea ice cover. We use a high-resolution unstructured grid 3-D ocean–sea ice–ice shelf setup, featuring an improved sub-ice-shelf bathymetry and a realistic PGIS geometry, to investigate in unprecedented detail the implications of transitions in the Nares Strait sea ice regime, that is, from a thick and landfast sea ice regime to a mobile, and further, a thin and mobile sea ice regime, with regard to PGIS basal melt. In all three sea ice regimes, basal melt near the grounding line (GL) presents a seasonal increase during summer, driven by a higher thermal driving. The stronger melt overturning increases the friction velocity slightly downstream, where enhanced friction-driven turbulent mixing further increases the thermal driving, substantially increasing the local melt. As the sea ice cover becomes mobile and thin, wind and (additionally in winter) convectively upwelled AW from the Nares Strait enter the PGIS cavity. While its effect on basal melting is largely limited to the shallower ( <200 m) drafts during winter, in summer it extends to the GL (ca. 600 m) depth. In the absence of an increase in thermal driving, increased melting under the deeper ( >200 m) drafts in winter is solely driven by the increased vertical shear of a more energetic boundary layer current. A similar behaviour is noted when transitioning from a mobile to a thin mobile sea ice cover in summer, when increases in thermal driving are negligible and increases in melt are congruent with increases in friction velocity. These results suggest that the projected continuation of the warming of the ... Article in Journal/Newspaper Arctic glacier Greenland Ice Sheet Ice Shelf Nares strait Petermann glacier Sea ice The Cryosphere Directory of Open Access Journals: DOAJ Articles Arctic Greenland Nares ENVELOPE(158.167,158.167,-81.450,-81.450) The Cryosphere 17 12 5255 5281 |
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 A. Prakash Q. Zhou T. Hattermann N. Kirchner Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
One of the last remaining floating tongues of the Greenland ice sheet (GrIS), the Petermann Glacier ice shelf (PGIS), is seasonally shielded from warm Atlantic water (AW) by the formation of sea ice arches in the Nares Strait. However, continued decline of the Arctic sea ice extent and thickness suggests that arch formation is likely to become anomalous, necessitating an investigation into the response of PGIS to a year-round mobile and thin sea ice cover. We use a high-resolution unstructured grid 3-D ocean–sea ice–ice shelf setup, featuring an improved sub-ice-shelf bathymetry and a realistic PGIS geometry, to investigate in unprecedented detail the implications of transitions in the Nares Strait sea ice regime, that is, from a thick and landfast sea ice regime to a mobile, and further, a thin and mobile sea ice regime, with regard to PGIS basal melt. In all three sea ice regimes, basal melt near the grounding line (GL) presents a seasonal increase during summer, driven by a higher thermal driving. The stronger melt overturning increases the friction velocity slightly downstream, where enhanced friction-driven turbulent mixing further increases the thermal driving, substantially increasing the local melt. As the sea ice cover becomes mobile and thin, wind and (additionally in winter) convectively upwelled AW from the Nares Strait enter the PGIS cavity. While its effect on basal melting is largely limited to the shallower ( <200 m) drafts during winter, in summer it extends to the GL (ca. 600 m) depth. In the absence of an increase in thermal driving, increased melting under the deeper ( >200 m) drafts in winter is solely driven by the increased vertical shear of a more energetic boundary layer current. A similar behaviour is noted when transitioning from a mobile to a thin mobile sea ice cover in summer, when increases in thermal driving are negligible and increases in melt are congruent with increases in friction velocity. These results suggest that the projected continuation of the warming of the ... |
format |
Article in Journal/Newspaper |
author |
A. Prakash Q. Zhou T. Hattermann N. Kirchner |
author_facet |
A. Prakash Q. Zhou T. Hattermann N. Kirchner |
author_sort |
A. Prakash |
title |
Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
title_short |
Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
title_full |
Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
title_fullStr |
Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
title_full_unstemmed |
Impact of the Nares Strait sea ice arches on the long-term stability of the Petermann Glacier ice shelf |
title_sort |
impact of the nares strait sea ice arches on the long-term stability of the petermann glacier ice shelf |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-5255-2023 https://doaj.org/article/bd3c54bed3f7401fa1a5807458244441 |
long_lat |
ENVELOPE(158.167,158.167,-81.450,-81.450) |
geographic |
Arctic Greenland Nares |
geographic_facet |
Arctic Greenland Nares |
genre |
Arctic glacier Greenland Ice Sheet Ice Shelf Nares strait Petermann glacier Sea ice The Cryosphere |
genre_facet |
Arctic glacier Greenland Ice Sheet Ice Shelf Nares strait Petermann glacier Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 5255-5281 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/5255/2023/tc-17-5255-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-5255-2023 1994-0416 1994-0424 https://doaj.org/article/bd3c54bed3f7401fa1a5807458244441 |
op_doi |
https://doi.org/10.5194/tc-17-5255-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
12 |
container_start_page |
5255 |
op_container_end_page |
5281 |
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1788059558987431936 |