On estimates for the vertical nitrate flux due to eddy pumping
Integral tracer methods consistently imply an annual new primary production of 0.5 +/- 0.15 mol N m(-2) yr(-1) for the Sargasso Sea region of the North Atlantic. It has been suggested that as much as half of this may be fueled by the vertical nitrate flux associated with "eddy pumping.'...
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ftnerc:oai:nora.nerc.ac.uk:101319 2023-05-15T17:34:49+02:00 On estimates for the vertical nitrate flux due to eddy pumping Martin, A.P. Pondaven, P. 2003-11 http://nora.nerc.ac.uk/id/eprint/101319/ https://doi.org/10.1029/2003JC001841 unknown Martin, A.P. orcid:0000-0002-1202-8612 Pondaven, P. 2003 On estimates for the vertical nitrate flux due to eddy pumping. Journal of Geophysical Research C (Oceans), 108 (C11). 03359-[10pp]. https://doi.org/10.1029/2003JC001841 <https://doi.org/10.1029/2003JC001841> Publication - Article PeerReviewed 2003 ftnerc https://doi.org/10.1029/2003JC001841 2023-02-04T19:33:29Z Integral tracer methods consistently imply an annual new primary production of 0.5 +/- 0.15 mol N m(-2) yr(-1) for the Sargasso Sea region of the North Atlantic. It has been suggested that as much as half of this may be fueled by the vertical nitrate flux associated with "eddy pumping.'' The key factor in estimates of eddy pumping is the relationship between the time for which water upwelled within eddies remains within the euphotic zone and the rate at which upwelled nutrients are consumed by phytoplankton. The uplift time is strongly influenced by the nature of the eddy, more specifically by its ability to trap waters within it as it propagates. We investigate two scenarios: If eddies propagate as nonlinear features, such that they retain the water within them for their lifetime, only a fraction of eddy "events'' observed at a fixed location actually contribute to the nitrate flux at that position; if eddies propagate as linear features, the efficiency of the pumping process, assumed in current altimetry-based estimates to be 100%, may be very significantly overestimated. Either scenario is shown to result in a major reduction in altimetry-based estimates of the vertical nitrate flux due to eddy pumping. Furthermore, the major contribution of local nitrification to the nitrate "recharging'' of previously uplifted waters, witnessed in our model, raises the possibility that much inferred new production in this area, based on nitrate uptake, is actually regenerated. Our results support the view that mesoscale eddy pumping may not be able to close the Sargasso Sea nitrate budget Article in Journal/Newspaper North Atlantic Natural Environment Research Council: NERC Open Research Archive Journal of Geophysical Research 108 C11 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
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unknown |
description |
Integral tracer methods consistently imply an annual new primary production of 0.5 +/- 0.15 mol N m(-2) yr(-1) for the Sargasso Sea region of the North Atlantic. It has been suggested that as much as half of this may be fueled by the vertical nitrate flux associated with "eddy pumping.'' The key factor in estimates of eddy pumping is the relationship between the time for which water upwelled within eddies remains within the euphotic zone and the rate at which upwelled nutrients are consumed by phytoplankton. The uplift time is strongly influenced by the nature of the eddy, more specifically by its ability to trap waters within it as it propagates. We investigate two scenarios: If eddies propagate as nonlinear features, such that they retain the water within them for their lifetime, only a fraction of eddy "events'' observed at a fixed location actually contribute to the nitrate flux at that position; if eddies propagate as linear features, the efficiency of the pumping process, assumed in current altimetry-based estimates to be 100%, may be very significantly overestimated. Either scenario is shown to result in a major reduction in altimetry-based estimates of the vertical nitrate flux due to eddy pumping. Furthermore, the major contribution of local nitrification to the nitrate "recharging'' of previously uplifted waters, witnessed in our model, raises the possibility that much inferred new production in this area, based on nitrate uptake, is actually regenerated. Our results support the view that mesoscale eddy pumping may not be able to close the Sargasso Sea nitrate budget |
format |
Article in Journal/Newspaper |
author |
Martin, A.P. Pondaven, P. |
spellingShingle |
Martin, A.P. Pondaven, P. On estimates for the vertical nitrate flux due to eddy pumping |
author_facet |
Martin, A.P. Pondaven, P. |
author_sort |
Martin, A.P. |
title |
On estimates for the vertical nitrate flux due to eddy pumping |
title_short |
On estimates for the vertical nitrate flux due to eddy pumping |
title_full |
On estimates for the vertical nitrate flux due to eddy pumping |
title_fullStr |
On estimates for the vertical nitrate flux due to eddy pumping |
title_full_unstemmed |
On estimates for the vertical nitrate flux due to eddy pumping |
title_sort |
on estimates for the vertical nitrate flux due to eddy pumping |
publishDate |
2003 |
url |
http://nora.nerc.ac.uk/id/eprint/101319/ https://doi.org/10.1029/2003JC001841 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Martin, A.P. orcid:0000-0002-1202-8612 Pondaven, P. 2003 On estimates for the vertical nitrate flux due to eddy pumping. Journal of Geophysical Research C (Oceans), 108 (C11). 03359-[10pp]. https://doi.org/10.1029/2003JC001841 <https://doi.org/10.1029/2003JC001841> |
op_doi |
https://doi.org/10.1029/2003JC001841 |
container_title |
Journal of Geophysical Research |
container_volume |
108 |
container_issue |
C11 |
_version_ |
1766133770041163776 |