Impact of coastal polynyas on dense shelf water formation in the Weddell Sea

Dense shelf water is an essential ingredient to the formation of Antarctic Bottom Water (AABW). It is formed on the continental shelves surrounding Antarctica, when freezing rates are sufficiently high to push ocean salinity to values of 34.65 and higher. Coastal polynyas, where the ice is driven aw...

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Main Authors: Haid, Verena, Timmermann, Ralph, Ebner, Lars, Heinemann, Günther
Format: Conference Object
Language:unknown
Published: Geophysical Research Abstracts 2013
Subjects:
Online Access:https://epic.awi.de/id/eprint/35356/
https://epic.awi.de/id/eprint/35356/1/Haid_et_al_2013_EGU.pdf
http://meetingorganizer.copernicus.org/EGU2013/EGU2013-10191.pdf
https://hdl.handle.net/10013/epic.43349
https://hdl.handle.net/10013/epic.43349.d001
id ftawi:oai:epic.awi.de:35356
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spelling ftawi:oai:epic.awi.de:35356 2023-05-15T13:40:26+02:00 Impact of coastal polynyas on dense shelf water formation in the Weddell Sea Haid, Verena Timmermann, Ralph Ebner, Lars Heinemann, Günther 2013-04-08 application/pdf https://epic.awi.de/id/eprint/35356/ https://epic.awi.de/id/eprint/35356/1/Haid_et_al_2013_EGU.pdf http://meetingorganizer.copernicus.org/EGU2013/EGU2013-10191.pdf https://hdl.handle.net/10013/epic.43349 https://hdl.handle.net/10013/epic.43349.d001 unknown Geophysical Research Abstracts https://epic.awi.de/id/eprint/35356/1/Haid_et_al_2013_EGU.pdf https://hdl.handle.net/10013/epic.43349.d001 Haid, V. , Timmermann, R. , Ebner, L. and Heinemann, G. (2013) Impact of coastal polynyas on dense shelf water formation in the Weddell Sea , EGU General Assembly 2013, Vienna, 2013 - unspecified . hdl:10013/epic.43349 EPIC3EGU General Assembly 2013, Vienna, 2013Vol. 15, EGU2013-10191, Geophysical Research Abstracts Conference notRev 2013 ftawi 2021-12-24T15:39:29Z Dense shelf water is an essential ingredient to the formation of Antarctic Bottom Water (AABW). It is formed on the continental shelves surrounding Antarctica, when freezing rates are sufficiently high to push ocean salinity to values of 34.65 and higher. Coastal polynyas, where the ice is driven away from the coastline, maintain the highest freezing rates in Antarctic winter. Since the Weddell Sea is considered the most productive source region of AABW, we investigate the dense water formation on the continental shelves of the southwestern Weddell Sea, with a focus on the role of coastal polynyas, using the Finite Element Sea ice-Ocean Model (FESOM), a primitive-equation, hydrostatic ocean model coupled with a dynamic-thermodynamic sea ice model. The horizontal resolution of the global, unstructured mesh is up to 3 km at the southwestern Weddell Sea coastline; in vertical direction the mesh features 37 depth levels (resolution increases toward the surface). The model was initialized on 01/01/1980 with data from the Polar Hydrographic Climatology and forced with NCEP/NCAR Reanalysis data. The 20-year period 1990-2009 is used for analysis. Our results indicate that in an average year, the polynya freezing rates of 9 cm/d cause a seasonal variation in salinity of 0.3 psu under the Ronne polynya and result in the production of dense shelf water, which leaves the continental shelf (outlined by the 700 m isobath in this study) at a long-term mean volume flux of 5.2 Sv. Some of this water contributes to the formation of Weddell Sea Deep/Bottom Water, but a large fraction is diluted by mixing with ambient water and leaves the Weddell Sea at intermediate levels. Conference Object Antarc* Antarctic Antarctica Sea ice Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Weddell Weddell Sea
institution Open Polar
collection Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
op_collection_id ftawi
language unknown
description Dense shelf water is an essential ingredient to the formation of Antarctic Bottom Water (AABW). It is formed on the continental shelves surrounding Antarctica, when freezing rates are sufficiently high to push ocean salinity to values of 34.65 and higher. Coastal polynyas, where the ice is driven away from the coastline, maintain the highest freezing rates in Antarctic winter. Since the Weddell Sea is considered the most productive source region of AABW, we investigate the dense water formation on the continental shelves of the southwestern Weddell Sea, with a focus on the role of coastal polynyas, using the Finite Element Sea ice-Ocean Model (FESOM), a primitive-equation, hydrostatic ocean model coupled with a dynamic-thermodynamic sea ice model. The horizontal resolution of the global, unstructured mesh is up to 3 km at the southwestern Weddell Sea coastline; in vertical direction the mesh features 37 depth levels (resolution increases toward the surface). The model was initialized on 01/01/1980 with data from the Polar Hydrographic Climatology and forced with NCEP/NCAR Reanalysis data. The 20-year period 1990-2009 is used for analysis. Our results indicate that in an average year, the polynya freezing rates of 9 cm/d cause a seasonal variation in salinity of 0.3 psu under the Ronne polynya and result in the production of dense shelf water, which leaves the continental shelf (outlined by the 700 m isobath in this study) at a long-term mean volume flux of 5.2 Sv. Some of this water contributes to the formation of Weddell Sea Deep/Bottom Water, but a large fraction is diluted by mixing with ambient water and leaves the Weddell Sea at intermediate levels.
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 dense shelf water formation in the Weddell Sea
author_facet Haid, Verena
Timmermann, Ralph
Ebner, Lars
Heinemann, Günther
author_sort Haid, Verena
title Impact of coastal polynyas on dense shelf water formation in the Weddell Sea
title_short Impact of coastal polynyas on dense shelf water formation in the Weddell Sea
title_full Impact of coastal polynyas on dense shelf water formation in the Weddell Sea
title_fullStr Impact of coastal polynyas on dense shelf water formation in the Weddell Sea
title_full_unstemmed Impact of coastal polynyas on dense shelf water formation in the Weddell Sea
title_sort impact of coastal polynyas on dense shelf water formation in the weddell sea
publisher Geophysical Research Abstracts
publishDate 2013
url https://epic.awi.de/id/eprint/35356/
https://epic.awi.de/id/eprint/35356/1/Haid_et_al_2013_EGU.pdf
http://meetingorganizer.copernicus.org/EGU2013/EGU2013-10191.pdf
https://hdl.handle.net/10013/epic.43349
https://hdl.handle.net/10013/epic.43349.d001
geographic Antarctic
Weddell
Weddell Sea
geographic_facet Antarctic
Weddell
Weddell Sea
genre Antarc*
Antarctic
Antarctica
Sea ice
Weddell Sea
genre_facet Antarc*
Antarctic
Antarctica
Sea ice
Weddell Sea
op_source EPIC3EGU General Assembly 2013, Vienna, 2013Vol. 15, EGU2013-10191, Geophysical Research Abstracts
op_relation https://epic.awi.de/id/eprint/35356/1/Haid_et_al_2013_EGU.pdf
https://hdl.handle.net/10013/epic.43349.d001
Haid, V. , Timmermann, R. , Ebner, L. and Heinemann, G. (2013) Impact of coastal polynyas on dense shelf water formation in the Weddell Sea , EGU General Assembly 2013, Vienna, 2013 - unspecified . hdl:10013/epic.43349
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