Project/Area Number |
09640520
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Meteorology/Physical oceanography/Hydrology
|
Research Institution | The University of Tokyo |
Principal Investigator |
HIBIYA Toshiyuki The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (80192714)
|
Project Period (FY) |
1997 – 1998
|
Project Status |
Completed (Fiscal Year 1998)
|
Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
Keywords | internal wave spectrum / energy cascade / nonlinear wave interactions / diapycnal diffusivity / ocean general circulation model / parameterization / near-inertial internal waves / midlatitude storms / 内部波スペクトル / 非線形干渉 / 乱波拡散 / 近慣性流 / 倍慣性周波数 / 中・深層 |
Research Abstract |
By using three-dimensional numerical models, the distribution of internal wave energy for diapycnalmixing in the deep waters of the North Pacific has been examined. During winter, energetic near-inertial waves are excited in response to the midlatitude storms in the western-central North Pacific (30゚N-45゚N). Thus excited waves propagate southward down to 10゚N-15゚N where the frequencies become double the local inertial frequencies so that large amount of wave energy cascades down to dissipation scales via Parametric Subharmonic Instability mechanism. The low-vertical-wavenumber double-inertial frequency internal waves are, in contrast, very weak at the times and locations of the previous microscale measurements so that the observed diapycnal diffusivity of-0.1 cm^2s^<-1> might not be representative.
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