2013 Fiscal Year Final Research Report
Spontaneous generation of organized current from random eddies in the ocean
| Project/Area Number |
23654167
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Kyushu University |
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Principal Investigator |
MASUDA Akira 九州大学, 応用力学研究所, 学術研究員 (60091401)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUTA Genta 北海道大学, 大学院・地球環境科学研究科, 助教 (30301948)
HIRABARA Mikitoshi 気象庁・気象研究所, 海洋研究部, 主任研究官 (70354545)
NAKANO Hideyuki 気象庁・気象研究所, 海洋研究部, 主任研究官 (60370334)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 不規則渦群から自発する組織構造 / 縞状東西流 / 再循環流 / 傾圧不安定 / 絶対渦度零の平均剪断流 / ロスビー波 / 三波相互作用 / 運動量・渦度の再分配 |
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| Research Abstract |
A riddle in physical oceanography has been why and how organized currents are generated spontaneously from random eddies in the ocean. In this study, by numerical experiment and dynamic investigation, we have attained several remarkable achievements for (1) Rhines effects, (2) recirculation in the Kuroshio Extension, (3) Neptune effects, (4) baroclinic-instability induced zonal current on a beta plane, (5) mean current with shear of zero absolute vorticity. As for common mechanisms underlying those phenomena, we have revealed important roles of such concepts as (1) nonlinear interaction of three wavenumber components, (2) dispersion relation of Rossby waves, (3) planetary and topographic beta effects, (4) redistribution of momentum and vorticity by Rossby waves, and (5) marginal stability. These results suggest future subjects to be studied and prospective approaches to be explored.
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