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題名 | TOGA COARE IOP期間大氣低頻擾動之特性 |
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作者姓名(中文) | 盧孟明; | 書刊名 | 大氣科學 |
卷期 | 23:1 1995.03[民84.03] |
頁次 | 頁65-91 |
分類號 | 328.2 |
關鍵詞 | 熱帶季內振盪; 中高緯低頻擾動; 熱帶與中高緯交互作用; Tropical intraseasonal oscillation; Midlatitude low-frequency disturbances; Tropical-extratropcial interactions; |
語文 | 中文(Chinese) |
中文摘要 | TOGA COARE IOP期間赤道附近的對流運動有明顯的低頻振盪現象。與之對應的振盪現象亦出現在熱帶地區高低層風場。我們發現在赤道東風增強之前,西亞或東亞之高層亞(副)熱帶西風噴流即開始增強;而赤道西風增強的個案中均有中緯度西風向赤道伸入的現象。另外,在中高緯度(50°N)的東西風分量也有明顯的低頻振盪現象。這些現象顯示出「低頻擾動」的複雜程度,即使在赤道附近也與簡單的「凱爾文-羅士比波」有許多不一致處。初步結果顯示熱帶低頻擾動與中高緯擾動是密不可分的。其間的「聯結」關鍵處除了赤道西風帶之外,以從北非到印度洋北側之高空亞熱帶噴流位置最為重要。 |
英文摘要 | Equatorial deep convection clearly oscillated with low-frequencies during the periodof TOGA COARE IOP. Corresponding oscillations are observed in the tropical wind field. We find that before upper equatorial easterly anomalies being intensified, the subtropical westerly jet stream over west or east Asia first become intensified. In the cases of strong equatorial westerly anomalies, subtropical westerlies are often found to intrude into the tropics. In addition, the low-frequency oscillations are also observed in midlatitude (50 ON) in east-west wind component of the upper tropospherical wind. Our results suggest that the low-frequency disturbances are not simple planetary waves. Even near the equator, the disturbances do not resemble the coupled Kelvin-Rossby modes. The low-frequency disturbances in the tropics and in the extratropics are not independent. The key location for connecting the low-frequency systems at different latitudial belts are the tropical westerly duct and the subtropical stream, extending from north Africa to the northern rim of the Indian Ocean. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。