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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 | 2014/06 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Isentropic Analysis of Polar Cold Airmass Streams in the Northern Hemispheric Winter |
| 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 | 71(6),pp.2230-2243 |
| 著者・共著者 | Toshiki Iwasaki,Takamichi Shoji,Yuki Kanno,Masahiro Sawada,Masashi Ujiie,Koutarou Takaya |
| 概要 | An analysis method is proposed for polar cold airmass streams from generation to disappearance. It designates a threshold potential temperature theta(T) at around the turning point of the extratropical direct (ETD) meridional circulation from downward to equatorward in the mass-weighted isentropic zonal mean (MIM) and clarifies the geographical distributions of the cold air mass, the negative heat content (NHC), their horizontal fluxes, and their diabatic change rates on the basis of conservation relations of the air mass and thermodynamic energy. In the Northern Hemispheric winter, the polar cold air mass below theta(T) = 280 K has two main streams: the East Asian stream and the North American stream. The former grows over the northern part of the Eurasian continent, flows eastward, turns down southeastward toward East Asia via Siberia, and disappears over the western North Pacific Ocean. The latter grows over the Arctic Ocean, flows toward the eastern coast of North America via Hudson Bay, and disappears over the western North Atlantic Ocean. In their exit regions, wave-mean flow interactions are considered to transfer the angular momentum from the cold airstreams to the upward Eliassen-Palm flux and convert the available potential energy to wave energy. |
| DOI | 10.1175/JAS-D-13-058.1 |
| ISSN | 0022-4928/1520-0469 |