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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 | 2005/12 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Mechanisms of intraseasonal amplification of the cold Siberian high |
| 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 | 62(12),pp.4423-4440 |
| 著者・共著者 | K Takaya,H Nakamura |
| 概要 | Mechanisms of intraseasonal amplification of the Siberian high are investigated on the basis of composite anomaly evolution for its strongest events at each of the grid points over Siberia. At each location, the amplification of the surface high is associated with formation of a blocking ridge in the upper troposphere. Over central and western Siberia, what may be called "wave-train (Atlantic-origin)" type is common, where a blocking ridge forms as a component of a quasi-stationary Rossby wave train propagating across the Eurasian continent. A cold air outbreak follows once anomalous surface cold air reaches the northeastern slope of the Tibetan Plateau.
It is found through the potential vorticity (PV) inversion technique that interaction between the upper-level stationary Rossby wave train and preexisting surface cold anomalies is essential for the strong amplification of the surface high. Upper-level PV anomalies associated with the wave train reinforce the cold anticyclonic anomalies at the surface by inducing anomalous cold advection that counteracts the tendency of the thermal anomalies themselves to migrate eastward as surface thermal Rossby waves. The surface cold anomalies thus intensified, in turn, act to induce anomalous vorticity advection aloft that reinforces the blocking ridge and cyclonic anomalies downstream of it that constitute the propagating wave train. The baroclinic development of the anomalies through this vertical coupling is manifested as a significant upward flux of wave activity emanating from the surface cold anomalies, which may be interpreted as dissipative destabilization of the incoming external Rossby waves. |
| ISSN | 0022-4928 |