題名: | A Study of the East Asian Cold Surges during 2004/05 Winter: The Impacts of East Asian Jet Stream and Subtropical Upper-level Rossby Wave Trains. |
作者: | 洪志誠;Chi-Cherng Hong;Huang-Hsiung Hsu;Hsin-Hsing Chia |
貢獻者: | 地球環境暨生物資源學系(含環境教育與資源碩士班) |
日期: | 2009-04 |
上傳時間: | 2014-01-17 19:30:38 (UTC+8) |
摘要: | Cold surges were unusually active in subtropical East Asia during January-February 2005. These cold surges were preceded by upstream wave trains,which originated in the Mediterranean-Sahara region and propagated eastward along the subtropical jet stream over the Eurasian continent. The northerly of upper-level cyclonic anomaly in East Asia coupled with the low-level northerly upon the arrival of wave activity, followed by the quick southward penetration of cold air mass and surface anticyclone. Diagnostic and numerical results suggest that the anomalously active wave activity affecting the East Asian cold surges may be attributed to the anomalously enhanced jet stream over Middle East and the anomalously westward extended East Asian Jet Stream. The configuration of these two subtropical jet streams established a strong waveguide through which the wave activity forced in the Mediterranean-Sahara region efficiently propagated to East Asia and resulted in more-than-averaged cold surge events in the subtropical East Asia. Wave-like perturbation tended to amplify at the entrance of the East Asian jet through barotropic energy conversion from the mean flow. |
關聯: | Terr. Atmos. Ocean Sci.,Vol. 20,Pages 333-343 |
顯示於類別: | [地球環境暨生物資源學系(含環境教育與資源碩士班)] 期刊論文
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