Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf
The Ross Sea polynya is among the most productive regions in the Southern Ocean and may constitute a significant oceanic CO2 sink. Based on results from several field studies, this region has been considered seasonally iron limited, whereby a "winter reserve" of dissolved iron (dFe) is pro...
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American Geophysical Union
2011
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ftncar:oai:drupal-site.org:articles_12313 2023-09-05T13:14:05+02:00 Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf Sedwick, P. (author) Marsay, C. (author) Sohst, B. (author) Aguilar-Islas, A. (author) Lohan, M. (author) Long, Matthew (author) Arrigo, K. (author) Dunbar, R. (author) Saito, M. (author) Smith, W. (author) DiTullio, G. (author) 2011-12-15 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-398 https://doi.org/10.1029/2010JC006553 en eng American Geophysical Union Journal of Geophysical Research-Oceans http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-398 doi:10.1029/2010JC006553 ark:/85065/d7tb17nt Copyright 2011 American Geophysical Union. Text article 2011 ftncar https://doi.org/10.1029/2010JC006553 2023-08-14T18:39:27Z The Ross Sea polynya is among the most productive regions in the Southern Ocean and may constitute a significant oceanic CO2 sink. Based on results from several field studies, this region has been considered seasonally iron limited, whereby a "winter reserve" of dissolved iron (dFe) is progressively depleted during the growing season to low concentrations (~0.1 nM) that limit phytoplankton growth in the austral summer (December-February). Here we report new iron data for the Ross Sea polynya during austral summer 2005-2006 (27 December-22 January) and the following austral spring 2006 (16 November-3 December). The summer 2005-2006 data show generally low dFe concentrations in polynya surface waters (0.10 ± 0.05 nM in upper 40 m, n = 175), consistent with previous observations. Surprisingly, our spring 2006 data reveal similar low surface dFe concentrations in the polynya (0.06 ± 0.04 nM in upper 40 m, n = 69), in association with relatively high rates of primary production (~170-260 mmol C m⁻² d⁻¹). These results indicate that the winter reserve dFe may be consumed relatively early in the growing season, such that polynya surface waters can become "iron limited" as early as November; i.e., the seasonal depletion of dFe is not necessarily gradual. Satellite observations reveal significant biomass accumulation in the polynya during summer 2006-2007, implying significant sources of "new" dFe to surface waters during this period. Possible sources of this new dFe include episodic vertical exchange, lateral advection, aerosol input, and reductive dissolution of particulate iron. Article in Journal/Newspaper Antarc* Antarctic Ross Sea Southern Ocean OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Antarctic Austral Ross Sea Southern Ocean The Antarctic Journal of Geophysical Research 116 C12 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
English |
description |
The Ross Sea polynya is among the most productive regions in the Southern Ocean and may constitute a significant oceanic CO2 sink. Based on results from several field studies, this region has been considered seasonally iron limited, whereby a "winter reserve" of dissolved iron (dFe) is progressively depleted during the growing season to low concentrations (~0.1 nM) that limit phytoplankton growth in the austral summer (December-February). Here we report new iron data for the Ross Sea polynya during austral summer 2005-2006 (27 December-22 January) and the following austral spring 2006 (16 November-3 December). The summer 2005-2006 data show generally low dFe concentrations in polynya surface waters (0.10 ± 0.05 nM in upper 40 m, n = 175), consistent with previous observations. Surprisingly, our spring 2006 data reveal similar low surface dFe concentrations in the polynya (0.06 ± 0.04 nM in upper 40 m, n = 69), in association with relatively high rates of primary production (~170-260 mmol C m⁻² d⁻¹). These results indicate that the winter reserve dFe may be consumed relatively early in the growing season, such that polynya surface waters can become "iron limited" as early as November; i.e., the seasonal depletion of dFe is not necessarily gradual. Satellite observations reveal significant biomass accumulation in the polynya during summer 2006-2007, implying significant sources of "new" dFe to surface waters during this period. Possible sources of this new dFe include episodic vertical exchange, lateral advection, aerosol input, and reductive dissolution of particulate iron. |
author2 |
Sedwick, P. (author) Marsay, C. (author) Sohst, B. (author) Aguilar-Islas, A. (author) Lohan, M. (author) Long, Matthew (author) Arrigo, K. (author) Dunbar, R. (author) Saito, M. (author) Smith, W. (author) DiTullio, G. (author) |
format |
Article in Journal/Newspaper |
title |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
spellingShingle |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
title_short |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
title_full |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
title_fullStr |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
title_full_unstemmed |
Early season depletion of dissolved iron in the Ross Sea polynya: Implications for iron dynamics on the Antarctic continental shelf |
title_sort |
early season depletion of dissolved iron in the ross sea polynya: implications for iron dynamics on the antarctic continental shelf |
publisher |
American Geophysical Union |
publishDate |
2011 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-398 https://doi.org/10.1029/2010JC006553 |
geographic |
Antarctic Austral Ross Sea Southern Ocean The Antarctic |
geographic_facet |
Antarctic Austral Ross Sea Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Ross Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Ross Sea Southern Ocean |
op_relation |
Journal of Geophysical Research-Oceans http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-398 doi:10.1029/2010JC006553 ark:/85065/d7tb17nt |
op_rights |
Copyright 2011 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2010JC006553 |
container_title |
Journal of Geophysical Research |
container_volume |
116 |
container_issue |
C12 |
_version_ |
1776205140826521600 |