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Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific
Title: | Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific |
Authors: | Nakanowatari, Takuya Browse this author →KAKEN DB | Nakamura, Tomohiro Browse this author →KAKEN DB | Uchimoto, Keisuke Browse this author →KAKEN DB | Nishioka, Jun Browse this author →KAKEN DB | Mitsudera, Humio Browse this author →KAKEN DB | Wakatsuchi, Masaaki Browse this author |
Issue Date: | 3-May-2017 |
Publisher: | American Geophysical Union |
Journal Title: | Journal of Geophysical Research: Oceans |
Volume: | 122 |
Issue: | 5 |
Start Page: | 4364 |
End Page: | 4391 |
Publisher DOI: | 10.1002/2016JC012354 |
Abstract: | 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. |
Rights: | Copyright [2017] American Geophysical Union. |
Type: | article |
URI: | http://hdl.handle.net/2115/72718 |
Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 中村 知裕
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