A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation
Leads in sea ice cover have been studied extensively because of the climatic relevance of the intense ocean–atmosphere heat exchange that occurs during winter. Leads are also preferential locations of heat exchange and melting in early summer, but their oceanography and climate relevance, if any, re...
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Online Access: | https://doi.org/10.5194/tc-17-3343-2023 https://tc.copernicus.org/articles/17/3343/2023/ |
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ftcopernicus:oai:publications.copernicus.org:tc108011 2023-09-26T15:14:45+02:00 A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation Alvarez, Alberto 2023-08-21 application/pdf https://doi.org/10.5194/tc-17-3343-2023 https://tc.copernicus.org/articles/17/3343/2023/ eng eng doi:10.5194/tc-17-3343-2023 https://tc.copernicus.org/articles/17/3343/2023/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-17-3343-2023 2023-08-28T16:24:16Z Leads in sea ice cover have been studied extensively because of the climatic relevance of the intense ocean–atmosphere heat exchange that occurs during winter. Leads are also preferential locations of heat exchange and melting in early summer, but their oceanography and climate relevance, if any, remains largely unexplored during summertime. In particular, the development of a near-surface temperature maximum (NSTM) layer typically 10–30 m deep under different Arctic basins has been observationally related to the penetration of solar radiation through the leads. These observations reveal that the concatenation of calm and wind events in the leads could facilitate the development of the NSTM layer. Using numerical modeling and an idealized framework, this study investigates the formation of the NSTM layer under a summer lead exposed to a combination of calm and moderate wind periods. During the calm period, solar heat accumulates in the upper layers under the lead. Near-surface convection cells are generated daily, extending from the lead sides to its center. Convection cells affect the heat storage in the mixed layer under the lead and the adjacent ice cap. A subsequent wind event (and corresponding ice drift) mixes and spreads fresh and cold meltwater into the warm layers near the surface. Surface mixing results in temperatures in the near-surface layers that are lower than in the deeper layers, where the impact of the surface stresses is weaker. Additionally, the warm waters initially located under the lead surface stretch and spread horizontally. Thus, an NSTM layer is formed. The study analyzes the sensitivity of the depth and temperature of the NSTM layer to buoyancy forcing, wind intensity, ice drift, stratification, and lead geometry. Numerical results suggest that the NSTM layer appears with moderate wind and ice drift and disappears when the wind intensity is higher than 9 m s −1 . Depending on the background stratification, the calm period reinforces or becomes critical in NSTM layer formation. ... Text Arctic Ice cap Sea ice Copernicus Publications: E-Journals Arctic The Cryosphere 17 8 3343 3361 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Leads in sea ice cover have been studied extensively because of the climatic relevance of the intense ocean–atmosphere heat exchange that occurs during winter. Leads are also preferential locations of heat exchange and melting in early summer, but their oceanography and climate relevance, if any, remains largely unexplored during summertime. In particular, the development of a near-surface temperature maximum (NSTM) layer typically 10–30 m deep under different Arctic basins has been observationally related to the penetration of solar radiation through the leads. These observations reveal that the concatenation of calm and wind events in the leads could facilitate the development of the NSTM layer. Using numerical modeling and an idealized framework, this study investigates the formation of the NSTM layer under a summer lead exposed to a combination of calm and moderate wind periods. During the calm period, solar heat accumulates in the upper layers under the lead. Near-surface convection cells are generated daily, extending from the lead sides to its center. Convection cells affect the heat storage in the mixed layer under the lead and the adjacent ice cap. A subsequent wind event (and corresponding ice drift) mixes and spreads fresh and cold meltwater into the warm layers near the surface. Surface mixing results in temperatures in the near-surface layers that are lower than in the deeper layers, where the impact of the surface stresses is weaker. Additionally, the warm waters initially located under the lead surface stretch and spread horizontally. Thus, an NSTM layer is formed. The study analyzes the sensitivity of the depth and temperature of the NSTM layer to buoyancy forcing, wind intensity, ice drift, stratification, and lead geometry. Numerical results suggest that the NSTM layer appears with moderate wind and ice drift and disappears when the wind intensity is higher than 9 m s −1 . Depending on the background stratification, the calm period reinforces or becomes critical in NSTM layer formation. ... |
format |
Text |
author |
Alvarez, Alberto |
spellingShingle |
Alvarez, Alberto A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
author_facet |
Alvarez, Alberto |
author_sort |
Alvarez, Alberto |
title |
A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
title_short |
A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
title_full |
A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
title_fullStr |
A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
title_full_unstemmed |
A model for the Arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
title_sort |
model for the arctic mixed layer circulation under a summertime lead: implications for the near-surface temperature maximum formation |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-3343-2023 https://tc.copernicus.org/articles/17/3343/2023/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Ice cap Sea ice |
genre_facet |
Arctic Ice cap Sea ice |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-17-3343-2023 https://tc.copernicus.org/articles/17/3343/2023/ |
op_doi |
https://doi.org/10.5194/tc-17-3343-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
8 |
container_start_page |
3343 |
op_container_end_page |
3361 |
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1778135600021372928 |