Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea
The thermohaline circulation of the world ocean is partly driven by deep water formation at high-latitudes. In the Southern Ocean, deep and bottom water formation in the marginal seas is induced by high freezing rates as generally found at coastal polynyas. Atmospheric cooling and brine-release enab...
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ftoceanrep:oai:oceanrep.geomar.de:26466 2023-05-15T18:17:17+02:00 Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea Haid, Verena Timmermann, Ralph Ebner, Lars Heinemann, Günther 2012 text https://oceanrep.geomar.de/id/eprint/26466/ https://oceanrep.geomar.de/id/eprint/26466/1/EGU2012-9797.pdf http://meetingorganizer.copernicus.org/EGU2011/EGU2012-9797.pdf en eng https://oceanrep.geomar.de/id/eprint/26466/1/EGU2012-9797.pdf Haid, V., Timmermann, R., Ebner, L. and Heinemann, G. (2012) Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea. [Other] In: EGU General Assembly 2012. , 22.04.-27.04.2012, Vienna, Austria . cc_by_nc Conference or Workshop Item NonPeerReviewed 2012 ftoceanrep 2023-04-07T15:15:53Z The thermohaline circulation of the world ocean is partly driven by deep water formation at high-latitudes. In the Southern Ocean, deep and bottom water formation in the marginal seas is induced by high freezing rates as generally found at coastal polynyas. Atmospheric cooling and brine-release enable the production of very cold and saline water masses. In the southwestern Weddell Sea, wide shelves allow for a strong salinification of the whole water column and the formation of High Salinity Shelf Water (HSSW). The impact of coastal polynyas on ice production and water mass formation in the southwestern Weddell Sea was studied employing the Finite Element Sea ice-Ocean Model (FESOM) of the Alfred Wegener Institute, Bremerhaven. FESOM is a coupled system of a primitive-equation, hydrostatic ocean model and a dynamic-thermodynamic sea ice model. Simulations were conducted on a global unstructured mesh with a strong focus on the southwestern Weddell Sea coastline (up to 3 km resolution). In vertical direction, the grid features 37 z-coordinate depth levels of which 6 are within the uppermost 100 m. The model runs were initialised in 1980 and forced with NCEP reanalysis data (daily resolution). The year 2008 was also simulated with higher-resolution GME and regional COSMO forcing data. For data evaluation and analysis the period 1990-2009 is used. A comparison of AMSR sea ice concentration and model results shows good accordance in spatial and temporal polynya extent. Also, calculated vertical temperature and salinity profiles agree well with CTD measurements. Our simulations feature a 20-year winter mean area of coastal polynyas of 6.7 x 10-3 km-2 (0.4% of the continental shelf area) in the southwestern Weddell Sea which is in good agreement with observations. Winter sea ice production within the coastal polynyas exceeds the ice production of the surrounding ice-covered area by a factor of 7 in the 20-year mean, so that the polynya contribution to total sea ice formation averages at about 3%. This small percentage ... Conference Object Sea ice Southern Ocean Weddell Sea OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Southern Ocean Weddell Sea Weddell |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The thermohaline circulation of the world ocean is partly driven by deep water formation at high-latitudes. In the Southern Ocean, deep and bottom water formation in the marginal seas is induced by high freezing rates as generally found at coastal polynyas. Atmospheric cooling and brine-release enable the production of very cold and saline water masses. In the southwestern Weddell Sea, wide shelves allow for a strong salinification of the whole water column and the formation of High Salinity Shelf Water (HSSW). The impact of coastal polynyas on ice production and water mass formation in the southwestern Weddell Sea was studied employing the Finite Element Sea ice-Ocean Model (FESOM) of the Alfred Wegener Institute, Bremerhaven. FESOM is a coupled system of a primitive-equation, hydrostatic ocean model and a dynamic-thermodynamic sea ice model. Simulations were conducted on a global unstructured mesh with a strong focus on the southwestern Weddell Sea coastline (up to 3 km resolution). In vertical direction, the grid features 37 z-coordinate depth levels of which 6 are within the uppermost 100 m. The model runs were initialised in 1980 and forced with NCEP reanalysis data (daily resolution). The year 2008 was also simulated with higher-resolution GME and regional COSMO forcing data. For data evaluation and analysis the period 1990-2009 is used. A comparison of AMSR sea ice concentration and model results shows good accordance in spatial and temporal polynya extent. Also, calculated vertical temperature and salinity profiles agree well with CTD measurements. Our simulations feature a 20-year winter mean area of coastal polynyas of 6.7 x 10-3 km-2 (0.4% of the continental shelf area) in the southwestern Weddell Sea which is in good agreement with observations. Winter sea ice production within the coastal polynyas exceeds the ice production of the surrounding ice-covered area by a factor of 7 in the 20-year mean, so that the polynya contribution to total sea ice formation averages at about 3%. This small percentage ... |
format |
Conference Object |
author |
Haid, Verena Timmermann, Ralph Ebner, Lars Heinemann, Günther |
spellingShingle |
Haid, Verena Timmermann, Ralph Ebner, Lars Heinemann, Günther Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
author_facet |
Haid, Verena Timmermann, Ralph Ebner, Lars Heinemann, Günther |
author_sort |
Haid, Verena |
title |
Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
title_short |
Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
title_full |
Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
title_fullStr |
Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
title_full_unstemmed |
Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea |
title_sort |
impact of coastal polynyas on sea ice production and water mass modification in the southwestern weddell sea |
publishDate |
2012 |
url |
https://oceanrep.geomar.de/id/eprint/26466/ https://oceanrep.geomar.de/id/eprint/26466/1/EGU2012-9797.pdf http://meetingorganizer.copernicus.org/EGU2011/EGU2012-9797.pdf |
geographic |
Southern Ocean Weddell Sea Weddell |
geographic_facet |
Southern Ocean Weddell Sea Weddell |
genre |
Sea ice Southern Ocean Weddell Sea |
genre_facet |
Sea ice Southern Ocean Weddell Sea |
op_relation |
https://oceanrep.geomar.de/id/eprint/26466/1/EGU2012-9797.pdf Haid, V., Timmermann, R., Ebner, L. and Heinemann, G. (2012) Impact of coastal polynyas on sea ice production and water mass modification in the southwestern Weddell Sea. [Other] In: EGU General Assembly 2012. , 22.04.-27.04.2012, Vienna, Austria . |
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cc_by_nc |
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1766191413709504512 |