Modelling the effect of submarine iceberg melting on glacier-adjacent water properties
The rate of ocean-driven retreat of Greenland's tidewater glaciers remains highly uncertain in predictions of future sea level rise, in part due to poorly constrained glacier-adjacent water properties. Icebergs and their meltwater contributions are likely important modifiers of fjord water prop...
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2022
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ftdoajarticles:oai:doaj.org/article:78594d2ff2094f9d8dc32d1f8adc395d 2023-05-15T16:40:47+02:00 Modelling the effect of submarine iceberg melting on glacier-adjacent water properties B. J. Davison T. Cowton A. Sole F. Cottier P. Nienow 2022-04-01T00:00:00Z https://doi.org/10.5194/tc-16-1181-2022 https://doaj.org/article/78594d2ff2094f9d8dc32d1f8adc395d EN eng Copernicus Publications https://tc.copernicus.org/articles/16/1181/2022/tc-16-1181-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-1181-2022 1994-0416 1994-0424 https://doaj.org/article/78594d2ff2094f9d8dc32d1f8adc395d The Cryosphere, Vol 16, Pp 1181-1196 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-1181-2022 2022-12-31T06:59:08Z The rate of ocean-driven retreat of Greenland's tidewater glaciers remains highly uncertain in predictions of future sea level rise, in part due to poorly constrained glacier-adjacent water properties. Icebergs and their meltwater contributions are likely important modifiers of fjord water properties, yet their effect is poorly understood. Here, we use a 3-D ocean circulation model, coupled to a submarine iceberg melt module, to investigate the effect of submarine iceberg melting on glacier-adjacent water properties in a range of idealised settings. Submarine iceberg melting can modify glacier-adjacent water properties in three principal ways: (1) substantial cooling and modest freshening in the upper ∼50 m of the water column; (2) warming of Polar Water at intermediate depths due to iceberg melt-induced upwelling of warm Atlantic Water and; (3) warming of the deeper Atlantic Water layer when vertical temperature gradients through this layer are steep (due to vertical mixing of warm water at depth) but cooling of the Atlantic Water layer when vertical temperature gradients are shallow. The overall effect of iceberg melt is to make glacier-adjacent water properties more uniform with depth. When icebergs extend to, or below, the depth of a sill at the fjord mouth, they can cause cooling throughout the entire water column. All of these effects are more pronounced in fjords with higher iceberg concentrations and deeper iceberg keel depths. These iceberg melt-induced changes to glacier-adjacent water properties will reduce rates of glacier submarine melting near the surface, increase them in the Polar Water layer, and cause typically modest impacts in the Atlantic Water layer. These results characterise the important role of submarine iceberg melting in modifying ice sheet-ocean interaction and highlight the need to improve representations of fjord processes in ice sheet scale models. Article in Journal/Newspaper Ice Sheet The Cryosphere Tidewater Directory of Open Access Journals: DOAJ Articles The Cryosphere 16 4 1181 1196 |
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 B. J. Davison T. Cowton A. Sole F. Cottier P. Nienow Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The rate of ocean-driven retreat of Greenland's tidewater glaciers remains highly uncertain in predictions of future sea level rise, in part due to poorly constrained glacier-adjacent water properties. Icebergs and their meltwater contributions are likely important modifiers of fjord water properties, yet their effect is poorly understood. Here, we use a 3-D ocean circulation model, coupled to a submarine iceberg melt module, to investigate the effect of submarine iceberg melting on glacier-adjacent water properties in a range of idealised settings. Submarine iceberg melting can modify glacier-adjacent water properties in three principal ways: (1) substantial cooling and modest freshening in the upper ∼50 m of the water column; (2) warming of Polar Water at intermediate depths due to iceberg melt-induced upwelling of warm Atlantic Water and; (3) warming of the deeper Atlantic Water layer when vertical temperature gradients through this layer are steep (due to vertical mixing of warm water at depth) but cooling of the Atlantic Water layer when vertical temperature gradients are shallow. The overall effect of iceberg melt is to make glacier-adjacent water properties more uniform with depth. When icebergs extend to, or below, the depth of a sill at the fjord mouth, they can cause cooling throughout the entire water column. All of these effects are more pronounced in fjords with higher iceberg concentrations and deeper iceberg keel depths. These iceberg melt-induced changes to glacier-adjacent water properties will reduce rates of glacier submarine melting near the surface, increase them in the Polar Water layer, and cause typically modest impacts in the Atlantic Water layer. These results characterise the important role of submarine iceberg melting in modifying ice sheet-ocean interaction and highlight the need to improve representations of fjord processes in ice sheet scale models. |
format |
Article in Journal/Newspaper |
author |
B. J. Davison T. Cowton A. Sole F. Cottier P. Nienow |
author_facet |
B. J. Davison T. Cowton A. Sole F. Cottier P. Nienow |
author_sort |
B. J. Davison |
title |
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
title_short |
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
title_full |
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
title_fullStr |
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
title_full_unstemmed |
Modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
title_sort |
modelling the effect of submarine iceberg melting on glacier-adjacent water properties |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-1181-2022 https://doaj.org/article/78594d2ff2094f9d8dc32d1f8adc395d |
genre |
Ice Sheet The Cryosphere Tidewater |
genre_facet |
Ice Sheet The Cryosphere Tidewater |
op_source |
The Cryosphere, Vol 16, Pp 1181-1196 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/1181/2022/tc-16-1181-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-1181-2022 1994-0416 1994-0424 https://doaj.org/article/78594d2ff2094f9d8dc32d1f8adc395d |
op_doi |
https://doi.org/10.5194/tc-16-1181-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
4 |
container_start_page |
1181 |
op_container_end_page |
1196 |
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1766031198526636032 |