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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Geophysical Research Abstracts
2013
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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 |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
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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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1766133940434763776 |