Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen
A simple model, using concentrations of nitrate and phosphate in austral winter 1992, reveals that the Antarctic Surface Water (AASW) of the southernmost Antarctic Circumpolar Current (ACC) between the Southern ACC Front and the Weddell Front is made up of about 90% Upper Circumpolar Deep Water (UCD...
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ftawi:oai:epic.awi.de:1430 2023-09-05T13:13:51+02:00 Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen Hoppema, Mario Fahrbach, Eberhard Baar, H. J. W. de 2000 https://epic.awi.de/id/eprint/1430/ http://dx.doi.org/2000JC000257 https://hdl.handle.net/10013/epic.12021 unknown Hoppema, M. orcid:0000-0002-2326-619X , Fahrbach, E. and Baar, H. J. W. d. (2000) Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen , Journal of Geophysical Research, 105, C5, pp. 11359-11371 . doi:2000JC000257 , hdl:10013/epic.12021 EPIC3Journal of Geophysical Research, 105, C5, pp. 11359-11371, ISSN: 0148-0227 Article isiRev 2000 ftawi 2023-08-22T19:42:40Z A simple model, using concentrations of nitrate and phosphate in austral winter 1992, reveals that the Antarctic Surface Water (AASW) of the southernmost Antarctic Circumpolar Current (ACC) between the Southern ACC Front and the Weddell Front is made up of about 90% Upper Circumpolar Deep Water (UCDW) and 10% northward-flowing AASW from the Weddell Gyre. With a typical time scale of about 1 year, the upwelling velocity was calculated to be as high as 60-100 m y-1. Knowing the composition of the surface water with respect to its sources, changes due to several processes in the surface layer were deduced for carbon dioxide, oxygen and silicate. As the time scale of changes in the surface layer of the southern ACC is about 1 year, this allows us to calculate changes on an annual basis without interference of short-term variations. Balancing the contributions by upwelling, biological activity and air-sea exchange to the concentrations in the surface layer, the area was found to be a large sink for atmospheric oxygen of 6.0 mol m-2 y-1 (53 µmol kg-1) and a small sink for atmospheric carbon dioxide of 1.0 mol m-2 y-1 (9 µmol kg-1). The most important cause for the oxygen sink is the upwelling of oxygen-poor UCDW, which surpasses the oxygen-elevating effect of primary productivity. This large oxygen sink, in between areas to the north and south which are only a small sink or even a source, conforms with the latitudinal distribution of atmospheric oxygen. The small CO2 sink is largely brought about by biological activity. The annual carbon utilization amounts to 76 ± 22 g C m-2 y-1, which is relatively high for an open ocean region in the Antarctic. However, it supports recent estimates of primary production of the Antarctic Ocean that are higher than early published values. The annual silicate consumption was calculated to be 126 ± 19 g Si m-2 y-1. This is considerably higher than the Southern Ocean mean in current estimates. Although the southernmost ACC may be atypical for the Southern Ocean, the current estimate for ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Ocean Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic Weddell |
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 |
A simple model, using concentrations of nitrate and phosphate in austral winter 1992, reveals that the Antarctic Surface Water (AASW) of the southernmost Antarctic Circumpolar Current (ACC) between the Southern ACC Front and the Weddell Front is made up of about 90% Upper Circumpolar Deep Water (UCDW) and 10% northward-flowing AASW from the Weddell Gyre. With a typical time scale of about 1 year, the upwelling velocity was calculated to be as high as 60-100 m y-1. Knowing the composition of the surface water with respect to its sources, changes due to several processes in the surface layer were deduced for carbon dioxide, oxygen and silicate. As the time scale of changes in the surface layer of the southern ACC is about 1 year, this allows us to calculate changes on an annual basis without interference of short-term variations. Balancing the contributions by upwelling, biological activity and air-sea exchange to the concentrations in the surface layer, the area was found to be a large sink for atmospheric oxygen of 6.0 mol m-2 y-1 (53 µmol kg-1) and a small sink for atmospheric carbon dioxide of 1.0 mol m-2 y-1 (9 µmol kg-1). The most important cause for the oxygen sink is the upwelling of oxygen-poor UCDW, which surpasses the oxygen-elevating effect of primary productivity. This large oxygen sink, in between areas to the north and south which are only a small sink or even a source, conforms with the latitudinal distribution of atmospheric oxygen. The small CO2 sink is largely brought about by biological activity. The annual carbon utilization amounts to 76 ± 22 g C m-2 y-1, which is relatively high for an open ocean region in the Antarctic. However, it supports recent estimates of primary production of the Antarctic Ocean that are higher than early published values. The annual silicate consumption was calculated to be 126 ± 19 g Si m-2 y-1. This is considerably higher than the Southern Ocean mean in current estimates. Although the southernmost ACC may be atypical for the Southern Ocean, the current estimate for ... |
format |
Article in Journal/Newspaper |
author |
Hoppema, Mario Fahrbach, Eberhard Baar, H. J. W. de |
spellingShingle |
Hoppema, Mario Fahrbach, Eberhard Baar, H. J. W. de Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
author_facet |
Hoppema, Mario Fahrbach, Eberhard Baar, H. J. W. de |
author_sort |
Hoppema, Mario |
title |
Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
title_short |
Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
title_full |
Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
title_fullStr |
Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
title_full_unstemmed |
Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen |
title_sort |
surface layer balance of the southern antarctic circumpolar current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for co2 and oxygen |
publishDate |
2000 |
url |
https://epic.awi.de/id/eprint/1430/ http://dx.doi.org/2000JC000257 https://hdl.handle.net/10013/epic.12021 |
geographic |
Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic Weddell |
geographic_facet |
Antarctic Antarctic Ocean Austral Southern Ocean The Antarctic Weddell |
genre |
Antarc* Antarctic Antarctic Ocean Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Ocean Southern Ocean |
op_source |
EPIC3Journal of Geophysical Research, 105, C5, pp. 11359-11371, ISSN: 0148-0227 |
op_relation |
Hoppema, M. orcid:0000-0002-2326-619X , Fahrbach, E. and Baar, H. J. W. d. (2000) Surface layer balance of the southern Antarctic Circumpolar Current (prime meridian) used to derive carbon and silicate consumptions and annual air-sea exchange for CO2 and oxygen , Journal of Geophysical Research, 105, C5, pp. 11359-11371 . doi:2000JC000257 , hdl:10013/epic.12021 |
_version_ |
1776204987884371968 |