1987 Fiscal Year Final Research Report Summary
Analytical and Numerical Study on Intermediate-Geostrophic Eddies
| Project/Area Number |
60540262
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
気象・海洋・陸水学
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| Research Institution | Kyushu University |
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Principal Investigator |
YAMAGATA TOSHIO Research Institute for Applied Mechanics, Kyushu University, 応用力学研究所, 助教授 (50091400)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUURA TOMONORI Faculty of Engineering, Ibaraki University, 工学部, 助手 (80165761)
UMATANI SHIN-ICHIRO Research Institute for Applied Mechanics, Kyushu University, 応用力学研究所, 助手 (30112353)
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| Project Period (FY) |
1985 – 1987
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| Keywords | IG equation / QG equation / PG equation / GG equation / Gulf Stream Ring / Kuroshio Large Meander / OGCM / 山形-Flierl方程式 |
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| Research Abstract |
1. We have generalized the IG equation to the degree at which either total energy or potential enstrophy of a reduced-gravity shallow water fluid system is conserved in time. In particular, we have derived new evolution equation using a perturbatin technique and have applied the equation to the satellite observed motion of a cyclonic Gulf Stream ring. The result has shown a superiority of the present model to the traditional quasi-geostrophic model
2. We have discussed the bimodelity of the Kuroshio path south of Japan from a new viewpoint of direct interaction of current with coastal geometry. By solving the barotropic quasi-geostrophic equation with step-like coastal geometry, we have demostrated that the model Kuroshio can actually show the localized, bimodal behavior for a reasonable range of inlet current speed.
3. We have developed a very tractable nonlinear shallow water ocean model which conserves potential enstrophy.
4. We have succeeded in transplanting the GFDL general circulation model to RIAM/Kyushu University. The next step is to adapt the model for our future model studies.
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