On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre
Sections from two 'Polarstern' cruises in austral winter 1992 and summer 1992/93 were used to track the course of Circumpolar Deep Water (CDW) in the Weddell Sea. Total inorganic carbon (TCO2) is a valuable tracer for that water mass because it allows to distinguish features that cannot be...
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ftawi:oai:epic.awi.de:1425 2024-09-15T17:45:15+00:00 On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre Hoppema, Mario Fahrbach, Eberhard Schröder, Michael 1997 https://epic.awi.de/id/eprint/1425/ https://hdl.handle.net/10013/epic.12016 unknown Hoppema, M. orcid:0000-0002-2326-619X , Fahrbach, E. and Schröder, M. (1997) On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre , Oceanologica Acta, 20 , pp. 783-798 . hdl:10013/epic.12016 EPIC3Oceanologica Acta, 20, pp. 783-798 Article isiRev 1997 ftawi 2024-06-24T03:53:34Z Sections from two 'Polarstern' cruises in austral winter 1992 and summer 1992/93 were used to track the course of Circumpolar Deep Water (CDW) in the Weddell Sea. Total inorganic carbon (TCO2) is a valuable tracer for that water mass because it allows to distinguish features that cannot be seen in the distributions of temperature and salinity. Upon entrance into the eastern Weddell Gyre, a shallow maximum in TCO2 at about 200 m (likewise a temperature maximum and oxygen minimum) indicates the depth level to which vertical mixing with Winter Water penetrates the CDW layer in the Weddell Gyre. The lower boundary of this CDW layer, which is not apparent in the temperature and salinity profiles, is a TCO2 maximum at 1000-1500 m (sq27.835), originating through the superposition of the recently advected CDW from the Antarctic Circumpolar Current and the Weddell Sea Deep Water (WSDW) with opposite vertical gradients. A coinciding, weak oxygen minimum is only present on the prime meridian and is probably caused bydifferent biological histories of the CDW and the WSDW underneath. Using this TCO2 maximum, the newly injected CDW can be traced as a well-defined band around the Weddell Sea up to south of the South Orkney plateau. Downstream in the northern limb of the Weddell Gyre at the prime meridian its trace has disappeared.The band of 'new' CDW, as part of the boundary current, envelopes a central area where currents are significantly smaller. In this interior a special modification of CDW, the Central Intermediate Water (CIW), can be distinguished. This water mass is characterised by a secondary TCO2 maximum and oxygen minimum, with no comparable structures in the temperature and salinitiy fields. CIW is enriched in CO2 compared to the CDW that enters the Weddell Gyre and is most pronounced in the western part of the Weddell basin. Data in the west suggest that the CIW is related to the lower part of the 'new'-CDW layer. Thus, the central Weddell basin is replenished from the west side rather than from the east. Within ... Article in Journal/Newspaper Antarc* Antarctic Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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 |
Sections from two 'Polarstern' cruises in austral winter 1992 and summer 1992/93 were used to track the course of Circumpolar Deep Water (CDW) in the Weddell Sea. Total inorganic carbon (TCO2) is a valuable tracer for that water mass because it allows to distinguish features that cannot be seen in the distributions of temperature and salinity. Upon entrance into the eastern Weddell Gyre, a shallow maximum in TCO2 at about 200 m (likewise a temperature maximum and oxygen minimum) indicates the depth level to which vertical mixing with Winter Water penetrates the CDW layer in the Weddell Gyre. The lower boundary of this CDW layer, which is not apparent in the temperature and salinity profiles, is a TCO2 maximum at 1000-1500 m (sq27.835), originating through the superposition of the recently advected CDW from the Antarctic Circumpolar Current and the Weddell Sea Deep Water (WSDW) with opposite vertical gradients. A coinciding, weak oxygen minimum is only present on the prime meridian and is probably caused bydifferent biological histories of the CDW and the WSDW underneath. Using this TCO2 maximum, the newly injected CDW can be traced as a well-defined band around the Weddell Sea up to south of the South Orkney plateau. Downstream in the northern limb of the Weddell Gyre at the prime meridian its trace has disappeared.The band of 'new' CDW, as part of the boundary current, envelopes a central area where currents are significantly smaller. In this interior a special modification of CDW, the Central Intermediate Water (CIW), can be distinguished. This water mass is characterised by a secondary TCO2 maximum and oxygen minimum, with no comparable structures in the temperature and salinitiy fields. CIW is enriched in CO2 compared to the CDW that enters the Weddell Gyre and is most pronounced in the western part of the Weddell basin. Data in the west suggest that the CIW is related to the lower part of the 'new'-CDW layer. Thus, the central Weddell basin is replenished from the west side rather than from the east. Within ... |
format |
Article in Journal/Newspaper |
author |
Hoppema, Mario Fahrbach, Eberhard Schröder, Michael |
spellingShingle |
Hoppema, Mario Fahrbach, Eberhard Schröder, Michael On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
author_facet |
Hoppema, Mario Fahrbach, Eberhard Schröder, Michael |
author_sort |
Hoppema, Mario |
title |
On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
title_short |
On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
title_full |
On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
title_fullStr |
On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
title_full_unstemmed |
On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre |
title_sort |
on the total carbon dioxide and oxygen signature of the circumpolar deep water in the weddell gyre |
publishDate |
1997 |
url |
https://epic.awi.de/id/eprint/1425/ https://hdl.handle.net/10013/epic.12016 |
genre |
Antarc* Antarctic Weddell Sea |
genre_facet |
Antarc* Antarctic Weddell Sea |
op_source |
EPIC3Oceanologica Acta, 20, pp. 783-798 |
op_relation |
Hoppema, M. orcid:0000-0002-2326-619X , Fahrbach, E. and Schröder, M. (1997) On the total carbon dioxide and oxygen signature of the Circumpolar Deep Water in the Weddell Gyre , Oceanologica Acta, 20 , pp. 783-798 . hdl:10013/epic.12016 |
_version_ |
1810493015535386624 |