Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection?
Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downwar...
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ftunivrhodeislan:oai:digitalcommons.uri.edu:gsofacpubs-2883 2024-02-04T10:04:51+01:00 Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? Boyd, P. W. Wong, C. S. Merrill, J. Whitney, F. Snow, J. Harrison, P. J. Gower, J. 1998-01-01T08:00:00Z https://digitalcommons.uri.edu/gsofacpubs/1914 https://doi.org/10.1029/98GB00745 unknown DigitalCommons@URI https://digitalcommons.uri.edu/gsofacpubs/1914 doi:10.1029/98GB00745 https://doi.org/10.1029/98GB00745 Graduate School of Oceanography Faculty Publications text 1998 ftunivrhodeislan https://doi.org/10.1029/98GB00745 2024-01-08T19:09:55Z Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that ong time sereis pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a(↑2.0 μm L-1) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OPS). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more production waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean. Text Subarctic Alaska University of Rhode Island: DigitalCommons@URI Pacific Global Biogeochemical Cycles 12 3 429 441 |
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University of Rhode Island: DigitalCommons@URI |
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ftunivrhodeislan |
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description |
Recent studies have confirmed the relationship between iron supply and phytoplankton growth rates in all three high-nitrate low-chlorophyll (HNLC) oceanic provinces. However, there is little evidence, so far, of the role of iron in altering the efficiency of the biological pump via increased downward export of particulate organic carbon (POC). The NE subarctic Pacific is unique among HNLC regions in that ong time sereis pelagic observations and deep-moored sediment trap records exist which may provide the best opportunity thus far to test aspects of the iron hypothesis. Episodic elevated levels of chlorophyll a(↑2.0 μm L-1) were observed 6 times between 1964 and 1976 at the former site of Ocean Station Papa (OPS). In addition, between 1984 and 1990 on at least three occasions, concurrent pulses of POC and biogenic silica were recorded in deep-moored traps at OSP. Possible explanations for these events, such as lateral advection of more production waters, iron-mediated blooms, or grazing by salp swarms are discussed and tested using an existing downward POC flux model. Owing to the episodic nature of such events, no available data are sufficiently comprehensive to unequivocally rule out any of these explanations. Nevertheless, from the data available, the occurrence of pelagic or deep water pulses, approximately once every 3 years, are most consistent with iron-mediated diatom blooms, and of the sinking of POC and biogenic silica (from such a bloom) to depth, respectively. A comparison of the timing of these iron-mediated pulses with that of the transport probabilities of atmospheric dust supply from Asia and Alaska provides an opportunity to assess the likelihood of a coupling between the atmosphere and the ocean. |
format |
Text |
author |
Boyd, P. W. Wong, C. S. Merrill, J. Whitney, F. Snow, J. Harrison, P. J. Gower, J. |
spellingShingle |
Boyd, P. W. Wong, C. S. Merrill, J. Whitney, F. Snow, J. Harrison, P. J. Gower, J. Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
author_facet |
Boyd, P. W. Wong, C. S. Merrill, J. Whitney, F. Snow, J. Harrison, P. J. Gower, J. |
author_sort |
Boyd, P. W. |
title |
Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
title_short |
Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
title_full |
Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
title_fullStr |
Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
title_full_unstemmed |
Atmospheric iron supply and enhanced vertical carbon flux in the NE subarctic Pacific: is there a connection? |
title_sort |
atmospheric iron supply and enhanced vertical carbon flux in the ne subarctic pacific: is there a connection? |
publisher |
DigitalCommons@URI |
publishDate |
1998 |
url |
https://digitalcommons.uri.edu/gsofacpubs/1914 https://doi.org/10.1029/98GB00745 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Subarctic Alaska |
genre_facet |
Subarctic Alaska |
op_source |
Graduate School of Oceanography Faculty Publications |
op_relation |
https://digitalcommons.uri.edu/gsofacpubs/1914 doi:10.1029/98GB00745 https://doi.org/10.1029/98GB00745 |
op_doi |
https://doi.org/10.1029/98GB00745 |
container_title |
Global Biogeochemical Cycles |
container_volume |
12 |
container_issue |
3 |
container_start_page |
429 |
op_container_end_page |
441 |
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1789973591326982144 |