A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea
International audience An inverse model is applied for the analysis of hydrographic and current meter data collected on the repeat WOCE section SR4 in the Weddell Sea in 1989?1992. The section crosses the Weddell Sea cyclonic gyre from Kapp Norvegia to the northern end of the Antarctic Peninsula. Th...
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1998
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Online Access: | https://hal.science/hal-00316437 https://hal.science/hal-00316437/document https://hal.science/hal-00316437/file/angeo-16-1024-1998.pdf |
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ftccsdartic:oai:HAL:hal-00316437v1 2024-02-11T09:58:54+01:00 A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea Yaremchuk, M. Nechaev, D. Schroter, J. Fahrbach, E. Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association P.P. Shirshov Institute of Oceanology (SIO) Russian Academy of Sciences Moscow (RAS) 1998 https://hal.science/hal-00316437 https://hal.science/hal-00316437/document https://hal.science/hal-00316437/file/angeo-16-1024-1998.pdf en eng HAL CCSD European Geosciences Union hal-00316437 https://hal.science/hal-00316437 https://hal.science/hal-00316437/document https://hal.science/hal-00316437/file/angeo-16-1024-1998.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316437 Annales Geophysicae, 1998, 16 (8), pp.1024-1038 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 1998 ftccsdartic 2024-01-21T00:49:27Z International audience An inverse model is applied for the analysis of hydrographic and current meter data collected on the repeat WOCE section SR4 in the Weddell Sea in 1989?1992. The section crosses the Weddell Sea cyclonic gyre from Kapp Norvegia to the northern end of the Antarctic Peninsula. The concepts of geostrophy, conservation of planetary vorticity and hydrostatics are combined with advective balances of active and passive properties to provide a dynamically consistent circulation pattern. Our variational assimilation scheme allows the calculation of three-dimensional velocities in the section plane. Current speeds are small except along the coasts where they reach up to 12 cm/s. We diagnose a gyre transport of 34 Sverdrup which is associated with a poleward heat transport of 28×10 12 W corresponding to an average heat flux of 15 Wm ?2 in the Weddell Sea south of the transect. This exceeds the estimated local flux on the transect of 2 Wm ?2 . As the transect is located mostly in the open ocean, we conclude that the shelf areas contribute significantly to the ocean-atmosphere exchange and are consequently key areas for the contribution of the Weddell Sea to global ocean ventilation. Conversion of water masses occuring south of the section transform 6.6±1.1 Sv of the inflowing warm deep water into approximately equal amounts of Weddell Sea deep water and Weddell Sea bottom water. The volume transport of surface water equals in the in- and outflow. This means that almost all newly formed surface water is involved in the deep and bottom water formation. Comparison with the results obtained by pure velocity interpolation combined with a hydrographic data subset indicates major differences in the derived salt transports and the water mass conversion of the surface water. The differences can be explained by deviations in the structure of the upper ocean currents to which shelf areas contribute significantly. Additionally a rigorous variance analysis is performed. When only hydrographic data are used for ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Weddell Sea Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Antarctic Antarctic Peninsula The Antarctic Weddell Weddell Sea |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Yaremchuk, M. Nechaev, D. Schroter, J. Fahrbach, E. A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience An inverse model is applied for the analysis of hydrographic and current meter data collected on the repeat WOCE section SR4 in the Weddell Sea in 1989?1992. The section crosses the Weddell Sea cyclonic gyre from Kapp Norvegia to the northern end of the Antarctic Peninsula. The concepts of geostrophy, conservation of planetary vorticity and hydrostatics are combined with advective balances of active and passive properties to provide a dynamically consistent circulation pattern. Our variational assimilation scheme allows the calculation of three-dimensional velocities in the section plane. Current speeds are small except along the coasts where they reach up to 12 cm/s. We diagnose a gyre transport of 34 Sverdrup which is associated with a poleward heat transport of 28×10 12 W corresponding to an average heat flux of 15 Wm ?2 in the Weddell Sea south of the transect. This exceeds the estimated local flux on the transect of 2 Wm ?2 . As the transect is located mostly in the open ocean, we conclude that the shelf areas contribute significantly to the ocean-atmosphere exchange and are consequently key areas for the contribution of the Weddell Sea to global ocean ventilation. Conversion of water masses occuring south of the section transform 6.6±1.1 Sv of the inflowing warm deep water into approximately equal amounts of Weddell Sea deep water and Weddell Sea bottom water. The volume transport of surface water equals in the in- and outflow. This means that almost all newly formed surface water is involved in the deep and bottom water formation. Comparison with the results obtained by pure velocity interpolation combined with a hydrographic data subset indicates major differences in the derived salt transports and the water mass conversion of the surface water. The differences can be explained by deviations in the structure of the upper ocean currents to which shelf areas contribute significantly. Additionally a rigorous variance analysis is performed. When only hydrographic data are used for ... |
author2 |
Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association P.P. Shirshov Institute of Oceanology (SIO) Russian Academy of Sciences Moscow (RAS) |
format |
Article in Journal/Newspaper |
author |
Yaremchuk, M. Nechaev, D. Schroter, J. Fahrbach, E. |
author_facet |
Yaremchuk, M. Nechaev, D. Schroter, J. Fahrbach, E. |
author_sort |
Yaremchuk, M. |
title |
A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
title_short |
A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
title_full |
A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
title_fullStr |
A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
title_full_unstemmed |
A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea |
title_sort |
dynamically consistent analysis of circulation and transports in the southwestern weddell sea |
publisher |
HAL CCSD |
publishDate |
1998 |
url |
https://hal.science/hal-00316437 https://hal.science/hal-00316437/document https://hal.science/hal-00316437/file/angeo-16-1024-1998.pdf |
geographic |
Antarctic Antarctic Peninsula The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Antarctic Peninsula The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctic Peninsula Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Weddell Sea |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316437 Annales Geophysicae, 1998, 16 (8), pp.1024-1038 |
op_relation |
hal-00316437 https://hal.science/hal-00316437 https://hal.science/hal-00316437/document https://hal.science/hal-00316437/file/angeo-16-1024-1998.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1790594704327311360 |