The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones
The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Su...
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ftunivtasecite:oai:ecite.utas.edu.au:73200 2023-05-15T14:02:30+02:00 The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones Cassar, N DiFiore, PJ Barnett, BA Bender, ML Bowie, AR Tilbrook, B Petrou, K Westwood, KJ Wright, SW Lefevre, D 2011 application/pdf https://doi.org/10.5194/bg-8-227-2011 http://ecite.utas.edu.au/73200 en eng Copernicus Publications http://ecite.utas.edu.au/73200/1/bg-8-227-2011.pdf http://dx.doi.org/10.5194/bg-8-227-2011 Cassar, N and DiFiore, PJ and Barnett, BA and Bender, ML and Bowie, AR and Tilbrook, B and Petrou, K and Westwood, KJ and Wright, SW and Lefevre, D, The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones, Biogeosciences, 8, (2) pp. 227-237. ISSN 1726-4170 (2011) [Refereed Article] http://ecite.utas.edu.au/73200 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2011 ftunivtasecite https://doi.org/10.5194/bg-8-227-2011 2019-12-13T21:40:20Z The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ) and the northern reaches of the Polar Frontal Zone (PFZ), we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense) study, which occurred in January-February 2007. Biological O2 supersaturation was derived from measuring O2/Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O2 m-2 d-1. NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (<50 m), dissolved Fe concentrations and Fe sufficiency, estimated from variable fluorescence, correlated strongly with NCP. The strong correlation between NCP and dissolved Fe may be difficult to interpret because of the correlation of dissolved Fe to MLD and because the concentration of iron may not be a good indicator of its availability. At stations with deeper mixed layers, NCP was consistently low, regardless of iron sufficiency, consistent with light availability also being an important control of NCP. Our new observations provide independent evidence for the critical roles of iron and light in mediating carbon export from the Southern Ocean mixed layer. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean eCite UTAS (University of Tasmania) Antarctic Austral Southern Ocean Biogeosciences 8 2 227 237 |
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Open Polar |
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eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Cassar, N DiFiore, PJ Barnett, BA Bender, ML Bowie, AR Tilbrook, B Petrou, K Westwood, KJ Wright, SW Lefevre, D The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
The roles of iron and light in controlling biomass and primary productivity are clearly established in the Southern Ocean. However, their influence on net community production (NCP) and carbon export remains to be quantified. To improve our understanding of NCP and carbon export production in the Subantarctic Zone (SAZ) and the northern reaches of the Polar Frontal Zone (PFZ), we conducted continuous onboard determinations of NCP as part of the Sub-Antarctic Sensitivity to Environmental Change (SAZ-Sense) study, which occurred in January-February 2007. Biological O2 supersaturation was derived from measuring O2/Ar ratios by equilibrator inlet mass spectrometry. Based on these continuous measurements, NCP during the austral summer 2007 in the Australian SAZ was approximately 43 mmol O2 m-2 d-1. NCP showed significant spatial variability, with larger values near the Subtropical front, and a general southward decrease. For shallower mixed layers (<50 m), dissolved Fe concentrations and Fe sufficiency, estimated from variable fluorescence, correlated strongly with NCP. The strong correlation between NCP and dissolved Fe may be difficult to interpret because of the correlation of dissolved Fe to MLD and because the concentration of iron may not be a good indicator of its availability. At stations with deeper mixed layers, NCP was consistently low, regardless of iron sufficiency, consistent with light availability also being an important control of NCP. Our new observations provide independent evidence for the critical roles of iron and light in mediating carbon export from the Southern Ocean mixed layer. |
format |
Article in Journal/Newspaper |
author |
Cassar, N DiFiore, PJ Barnett, BA Bender, ML Bowie, AR Tilbrook, B Petrou, K Westwood, KJ Wright, SW Lefevre, D |
author_facet |
Cassar, N DiFiore, PJ Barnett, BA Bender, ML Bowie, AR Tilbrook, B Petrou, K Westwood, KJ Wright, SW Lefevre, D |
author_sort |
Cassar, N |
title |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_short |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_full |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_fullStr |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_full_unstemmed |
The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones |
title_sort |
influence of iron and light on net community production in the subantarctic and polar frontal zones |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/bg-8-227-2011 http://ecite.utas.edu.au/73200 |
geographic |
Antarctic Austral Southern Ocean |
geographic_facet |
Antarctic Austral Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://ecite.utas.edu.au/73200/1/bg-8-227-2011.pdf http://dx.doi.org/10.5194/bg-8-227-2011 Cassar, N and DiFiore, PJ and Barnett, BA and Bender, ML and Bowie, AR and Tilbrook, B and Petrou, K and Westwood, KJ and Wright, SW and Lefevre, D, The influence of iron and light on net community production in the Subantarctic and Polar Frontal Zones, Biogeosciences, 8, (2) pp. 227-237. ISSN 1726-4170 (2011) [Refereed Article] http://ecite.utas.edu.au/73200 |
op_doi |
https://doi.org/10.5194/bg-8-227-2011 |
container_title |
Biogeosciences |
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8 |
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2 |
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227 |
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237 |
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