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タカヤ コウタロウ
TAKAYA KOTARO
高谷 康太郎 所属 京都産業大学 理学部 宇宙物理・気象学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2015/07 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | A Divergence-Form Wave-Induced Pressure Inherent in the Extension of the Eliassen-Palm Theory to a Three-Dimensional Framework for All Waves at All Latitudes |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF THE ATMOSPHERIC SCIENCES |
| 出版社・発行元 | AMER METEOROLOGICAL SOC |
| 巻・号・頁 | 72(7),pp.2822-2849 |
| 著者・共著者 | Hidenori Aiki,Koutarou Takaya,Richard J. Greatbatch |
| 概要 | Classical theory concerning the Eliassen-Palm relation is extended in this study to allow for a unified treatment of midlatitude inertia-gravity waves (MIGWs), midlatitude Rossby waves (MRWs), and equatorial waves (EQWs). A conservation equation for what the authors call the impulse-bolus (IB) pseudomomentum is useful, because it is applicable to ageostrophic waves, and the associated three-dimensional flux is parallel to the direction of the group velocity of MRWs. The equation has previously been derived in an isentropic coordinate system or a shallow-water model. The authors make an explicit comparison of prognostic equations for the IB pseudomomentum vector and the classical energy-based (CE) pseudomomentum vector, assuming inviscid linear waves in a sufficiently weak mean flow, to provide a basis for the former quantity to be used in an Eulerian time-mean (EM) framework. The authors investigate what makes the three-dimensional fluxes in the IB and CE pseudomomentum equations look in different directions. It is found that the two fluxes are linked by a gauge transformation, previously unmentioned, associated with a divergence-form wave-induced pressure
[GRAPHICS] . The quantity [GRAPHICS] vanishes for MIGWs and becomes nonzero for MRWs and EQWs, and it may be estimated using the virial theorem. Concerning the effect of waves on the mean flow, [GRAPHICS] represents an additional effect in the pressure gradient term of both (the three-dimensional versions of) the transformed EM momentum equations and the merged form of the EM momentum equations, the latter of which is associated with the nonacceleration theorem. |
| DOI | 10.1175/JAS-D-14-0172.1 |
| ISSN | 0022-4928/1520-0469 |