Antarctic ice sheet fertilises the Southern Ocean
Southern Ocean (SO) marine primary productivity (PP) is strongly influenced by the availability of iron in surface waters, which is thought to exert a significant control upon atmospheric CO 2 concentrations on glacial/interglacial timescales. The zone bordering the Antarctic Ice Sheet exhibits high...
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ftcopernicus:oai:publications.copernicus.org:bg20827 2023-05-15T13:45:55+02:00 Antarctic ice sheet fertilises the Southern Ocean Death, R. Wadham, J. L. Monteiro, F. Le Brocq, A. M. Tranter, M. Ridgwell, A. Dutkiewicz, S. Raiswell, R. 2018-09-27 application/pdf https://doi.org/10.5194/bg-11-2635-2014 https://www.biogeosciences.net/11/2635/2014/ eng eng doi:10.5194/bg-11-2635-2014 https://www.biogeosciences.net/11/2635/2014/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-11-2635-2014 2019-12-24T09:54:30Z Southern Ocean (SO) marine primary productivity (PP) is strongly influenced by the availability of iron in surface waters, which is thought to exert a significant control upon atmospheric CO 2 concentrations on glacial/interglacial timescales. The zone bordering the Antarctic Ice Sheet exhibits high PP and seasonal plankton blooms in response to light and variations in iron availability. The sources of iron stimulating elevated SO PP are in debate. Established contributors include dust, coastal sediments/upwelling, icebergs and sea ice. Subglacial meltwater exported at the ice margin is a more recent suggestion, arising from intense iron cycling beneath the ice sheet. Icebergs and subglacial meltwater may supply a large amount of bioavailable iron to the SO, estimated in this study at 0.07–0.2 Tg yr −1 . Here we apply the MIT global ocean model (Follows et al., 2007) to determine the potential impact of this level of iron export from the ice sheet upon SO PP. The export of iron from the ice sheet raises modelled SO PP by up to 40%, and provides one plausible explanation for seasonally very high in situ measurements of PP in the near-coastal zone. The impact on SO PP is greatest in coastal regions, which are also areas of high measured marine PP. These results suggest that the export of Antarctic runoff and icebergs may have an important impact on SO PP and should be included in future biogeochemical modelling. Text Antarc* Antarctic Ice Sheet Iceberg* Sea ice Southern Ocean Copernicus Publications: E-Journals Antarctic Southern Ocean The Antarctic Biogeosciences 11 10 2635 2643 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Southern Ocean (SO) marine primary productivity (PP) is strongly influenced by the availability of iron in surface waters, which is thought to exert a significant control upon atmospheric CO 2 concentrations on glacial/interglacial timescales. The zone bordering the Antarctic Ice Sheet exhibits high PP and seasonal plankton blooms in response to light and variations in iron availability. The sources of iron stimulating elevated SO PP are in debate. Established contributors include dust, coastal sediments/upwelling, icebergs and sea ice. Subglacial meltwater exported at the ice margin is a more recent suggestion, arising from intense iron cycling beneath the ice sheet. Icebergs and subglacial meltwater may supply a large amount of bioavailable iron to the SO, estimated in this study at 0.07–0.2 Tg yr −1 . Here we apply the MIT global ocean model (Follows et al., 2007) to determine the potential impact of this level of iron export from the ice sheet upon SO PP. The export of iron from the ice sheet raises modelled SO PP by up to 40%, and provides one plausible explanation for seasonally very high in situ measurements of PP in the near-coastal zone. The impact on SO PP is greatest in coastal regions, which are also areas of high measured marine PP. These results suggest that the export of Antarctic runoff and icebergs may have an important impact on SO PP and should be included in future biogeochemical modelling. |
format |
Text |
author |
Death, R. Wadham, J. L. Monteiro, F. Le Brocq, A. M. Tranter, M. Ridgwell, A. Dutkiewicz, S. Raiswell, R. |
spellingShingle |
Death, R. Wadham, J. L. Monteiro, F. Le Brocq, A. M. Tranter, M. Ridgwell, A. Dutkiewicz, S. Raiswell, R. Antarctic ice sheet fertilises the Southern Ocean |
author_facet |
Death, R. Wadham, J. L. Monteiro, F. Le Brocq, A. M. Tranter, M. Ridgwell, A. Dutkiewicz, S. Raiswell, R. |
author_sort |
Death, R. |
title |
Antarctic ice sheet fertilises the Southern Ocean |
title_short |
Antarctic ice sheet fertilises the Southern Ocean |
title_full |
Antarctic ice sheet fertilises the Southern Ocean |
title_fullStr |
Antarctic ice sheet fertilises the Southern Ocean |
title_full_unstemmed |
Antarctic ice sheet fertilises the Southern Ocean |
title_sort |
antarctic ice sheet fertilises the southern ocean |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-11-2635-2014 https://www.biogeosciences.net/11/2635/2014/ |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Iceberg* Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Ice Sheet Iceberg* Sea ice Southern Ocean |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-11-2635-2014 https://www.biogeosciences.net/11/2635/2014/ |
op_doi |
https://doi.org/10.5194/bg-11-2635-2014 |
container_title |
Biogeosciences |
container_volume |
11 |
container_issue |
10 |
container_start_page |
2635 |
op_container_end_page |
2643 |
_version_ |
1766232366142980096 |