Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq
The role of icebergs in narrow fjords hosting marine-terminating glaciers in Greenland is poorly understood, even though iceberg melt results in a substantial freshwater flux that can exceed the subglacial discharge. Furthermore, the melting of deep-keeled icebergs modifies the vertical stratificati...
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Copernicus Publications
2023
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ftdoajarticles:oai:doaj.org/article:204bb135baee4112b1b9148f15e5080a 2023-05-15T16:21:08+02:00 Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq K. Kajanto F. Straneo K. Nisancioglu 2023-01-01T00:00:00Z https://doi.org/10.5194/tc-17-371-2023 https://doaj.org/article/204bb135baee4112b1b9148f15e5080a EN eng Copernicus Publications https://tc.copernicus.org/articles/17/371/2023/tc-17-371-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-371-2023 1994-0416 1994-0424 https://doaj.org/article/204bb135baee4112b1b9148f15e5080a The Cryosphere, Vol 17, Pp 371-390 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-371-2023 2023-01-29T01:27:45Z The role of icebergs in narrow fjords hosting marine-terminating glaciers in Greenland is poorly understood, even though iceberg melt results in a substantial freshwater flux that can exceed the subglacial discharge. Furthermore, the melting of deep-keeled icebergs modifies the vertical stratification of the fjord and, as such, can impact ice–ocean exchanges at the glacier front. We model an idealised representation of the high-silled Ilulissat Icefjord in West Greenland with the MITgcm ocean circulation model, using the IceBerg package to study the effect of submarine iceberg melt on fjord water properties over a runoff season, and compare our results with available observations from 2014. We find the subglacial discharge plume to be the primary driver of the seasonality of circulation, glacier melt and iceberg melt. Furthermore, we find that melting of icebergs modifies the fjord in three main ways: first, icebergs cool and freshen the water column over their vertical extent; second, iceberg-melt-induced changes to fjord stratification cause the neutral buoyancy depth of the plume and the export of glacially modified waters to be deeper; third, icebergs modify the deep basin, below their vertical extent, by driving mixing of the glacially modified waters with the deep-basin waters and by modifying the incoming ambient waters. Through the combination of cooling and causing the subglacial-discharge-driven plume to equilibrate deeper, icebergs suppress glacier melting in the upper layer, resulting in undercutting of the glacier front. Finally, we postulate that the impact of submarine iceberg melt on the neutral buoyancy depth of the plume is a key mechanism linking the presence of an iceberg mélange with the glacier front, without needing to invoke mechanical effects. Article in Journal/Newspaper glacier Greenland Ilulissat Kujalleq Sermeq Kujalleq The Cryosphere Directory of Open Access Journals: DOAJ Articles Greenland Ilulissat ENVELOPE(-51.099,-51.099,69.220,69.220) Kujalleq ENVELOPE(-46.037,-46.037,60.719,60.719) The Cryosphere 17 1 371 390 |
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 K. Kajanto F. Straneo K. Nisancioglu Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The role of icebergs in narrow fjords hosting marine-terminating glaciers in Greenland is poorly understood, even though iceberg melt results in a substantial freshwater flux that can exceed the subglacial discharge. Furthermore, the melting of deep-keeled icebergs modifies the vertical stratification of the fjord and, as such, can impact ice–ocean exchanges at the glacier front. We model an idealised representation of the high-silled Ilulissat Icefjord in West Greenland with the MITgcm ocean circulation model, using the IceBerg package to study the effect of submarine iceberg melt on fjord water properties over a runoff season, and compare our results with available observations from 2014. We find the subglacial discharge plume to be the primary driver of the seasonality of circulation, glacier melt and iceberg melt. Furthermore, we find that melting of icebergs modifies the fjord in three main ways: first, icebergs cool and freshen the water column over their vertical extent; second, iceberg-melt-induced changes to fjord stratification cause the neutral buoyancy depth of the plume and the export of glacially modified waters to be deeper; third, icebergs modify the deep basin, below their vertical extent, by driving mixing of the glacially modified waters with the deep-basin waters and by modifying the incoming ambient waters. Through the combination of cooling and causing the subglacial-discharge-driven plume to equilibrate deeper, icebergs suppress glacier melting in the upper layer, resulting in undercutting of the glacier front. Finally, we postulate that the impact of submarine iceberg melt on the neutral buoyancy depth of the plume is a key mechanism linking the presence of an iceberg mélange with the glacier front, without needing to invoke mechanical effects. |
format |
Article in Journal/Newspaper |
author |
K. Kajanto F. Straneo K. Nisancioglu |
author_facet |
K. Kajanto F. Straneo K. Nisancioglu |
author_sort |
K. Kajanto |
title |
Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
title_short |
Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
title_full |
Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
title_fullStr |
Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
title_full_unstemmed |
Impact of icebergs on the seasonal submarine melt of Sermeq Kujalleq |
title_sort |
impact of icebergs on the seasonal submarine melt of sermeq kujalleq |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-371-2023 https://doaj.org/article/204bb135baee4112b1b9148f15e5080a |
long_lat |
ENVELOPE(-51.099,-51.099,69.220,69.220) ENVELOPE(-46.037,-46.037,60.719,60.719) |
geographic |
Greenland Ilulissat Kujalleq |
geographic_facet |
Greenland Ilulissat Kujalleq |
genre |
glacier Greenland Ilulissat Kujalleq Sermeq Kujalleq The Cryosphere |
genre_facet |
glacier Greenland Ilulissat Kujalleq Sermeq Kujalleq The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 371-390 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/371/2023/tc-17-371-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-371-2023 1994-0416 1994-0424 https://doaj.org/article/204bb135baee4112b1b9148f15e5080a |
op_doi |
https://doi.org/10.5194/tc-17-371-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
1 |
container_start_page |
371 |
op_container_end_page |
390 |
_version_ |
1766009150696849408 |