Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific
Iron (Fe) is an essential nutrient for marine phytoplankton and it constitutes an important element in the marine carbon cycle in the ocean. This study examined the mechanisms controlling seasonal variation of dissolved Fe (dFe) in the western subarctic North Pacific (WSNP), using an ocean general c...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | http://hdl.handle.net/2115/72718 https://doi.org/10.1002/2016JC012354 |
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fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/72718 2023-05-15T18:28:03+02:00 Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific Nakanowatari, Takuya Nakamura, Tomohiro Uchimoto, Keisuke Nishioka, Jun Mitsudera, Humio Wakatsuchi, Masaaki http://hdl.handle.net/2115/72718 https://doi.org/10.1002/2016JC012354 unknown American Geophysical Union http://hdl.handle.net/2115/72718 Journal of Geophysical Research: Oceans, 122(5): 4364-4391 http://dx.doi.org/10.1002/2016JC012354 Copyright [2017] American Geophysical Union. 452 article fthokunivhus https://doi.org/10.1002/2016JC012354 2022-11-18T01:05:14Z Iron (Fe) is an essential nutrient for marine phytoplankton and it constitutes an important element in the marine carbon cycle in the ocean. This study examined the mechanisms controlling seasonal variation of dissolved Fe (dFe) in the western subarctic North Pacific (WSNP), using an ocean general circulation model coupled with a simple biogeochemical model incorporating a dFe cycle fed by two major sources (atmospheric dust and continental shelf sediment). The model reproduced the seasonal cycle of observed concentrations of dFe and macronutrients at the surface in the Oyashio region with maxima in winter (February–March) and minima in summer (July–September), although the simulated seasonal amplitudes are a half of the observed values. Analysis of the mixed‐layer dFe budget indicated that both local vertical entrainment and lateral advection are primary contributors to the wintertime increase in dFe concentration. In early winter, strengthened northwesterly winds excite southward Ekman transport and Ekman upwelling over the western subarctic gyre, transporting dFe‐rich water southward. In mid to late winter, the southward western boundary current of the subarctic gyre and the outflow from the Sea of Okhotsk also bring dFe‐rich water to the Oyashio region. The contribution of atmospheric dust to the dFe budget is several times smaller than these ocean transport processes in winter. These results suggest that the westerly wind‐induced Ekman transport and gyre circulation systematically influence the seasonal cycle of WSNP surface dFe concentration. Article in Journal/Newspaper Subarctic Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Okhotsk Oyashio ENVELOPE(157.000,157.000,50.000,50.000) Pacific Journal of Geophysical Research: Oceans 122 5 4364 4391 |
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Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
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fthokunivhus |
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unknown |
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452 |
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452 Nakanowatari, Takuya Nakamura, Tomohiro Uchimoto, Keisuke Nishioka, Jun Mitsudera, Humio Wakatsuchi, Masaaki Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
topic_facet |
452 |
description |
Iron (Fe) is an essential nutrient for marine phytoplankton and it constitutes an important element in the marine carbon cycle in the ocean. This study examined the mechanisms controlling seasonal variation of dissolved Fe (dFe) in the western subarctic North Pacific (WSNP), using an ocean general circulation model coupled with a simple biogeochemical model incorporating a dFe cycle fed by two major sources (atmospheric dust and continental shelf sediment). The model reproduced the seasonal cycle of observed concentrations of dFe and macronutrients at the surface in the Oyashio region with maxima in winter (February–March) and minima in summer (July–September), although the simulated seasonal amplitudes are a half of the observed values. Analysis of the mixed‐layer dFe budget indicated that both local vertical entrainment and lateral advection are primary contributors to the wintertime increase in dFe concentration. In early winter, strengthened northwesterly winds excite southward Ekman transport and Ekman upwelling over the western subarctic gyre, transporting dFe‐rich water southward. In mid to late winter, the southward western boundary current of the subarctic gyre and the outflow from the Sea of Okhotsk also bring dFe‐rich water to the Oyashio region. The contribution of atmospheric dust to the dFe budget is several times smaller than these ocean transport processes in winter. These results suggest that the westerly wind‐induced Ekman transport and gyre circulation systematically influence the seasonal cycle of WSNP surface dFe concentration. |
format |
Article in Journal/Newspaper |
author |
Nakanowatari, Takuya Nakamura, Tomohiro Uchimoto, Keisuke Nishioka, Jun Mitsudera, Humio Wakatsuchi, Masaaki |
author_facet |
Nakanowatari, Takuya Nakamura, Tomohiro Uchimoto, Keisuke Nishioka, Jun Mitsudera, Humio Wakatsuchi, Masaaki |
author_sort |
Nakanowatari, Takuya |
title |
Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
title_short |
Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
title_full |
Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
title_fullStr |
Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
title_full_unstemmed |
Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
title_sort |
importance of ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic north pacific |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/2115/72718 https://doi.org/10.1002/2016JC012354 |
long_lat |
ENVELOPE(157.000,157.000,50.000,50.000) |
geographic |
Okhotsk Oyashio Pacific |
geographic_facet |
Okhotsk Oyashio Pacific |
genre |
Subarctic |
genre_facet |
Subarctic |
op_relation |
http://hdl.handle.net/2115/72718 Journal of Geophysical Research: Oceans, 122(5): 4364-4391 http://dx.doi.org/10.1002/2016JC012354 |
op_rights |
Copyright [2017] American Geophysical Union. |
op_doi |
https://doi.org/10.1002/2016JC012354 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
122 |
container_issue |
5 |
container_start_page |
4364 |
op_container_end_page |
4391 |
_version_ |
1766210387935494144 |