研究生: |
張卜仁 |
---|---|
論文名稱: |
亞洲夏季季風季內振盪之分析與模擬 |
指導教授: |
鄒治華
Tsou, Chih-Hua 柯文雄 Kau, Wen-Shung |
學位類別: |
碩士 Master |
系所名稱: |
地球科學系 Department of Earth Sciences |
畢業學年度: | 87 |
語文別: | 中文 |
論文頁數: | 49 |
中文關鍵詞: | 亞洲季風 、季內振盪 |
論文種類: | 學術論文 |
相關次數: | 點閱:171 下載:0 |
分享至: |
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
摘要
大尺度環流的突然轉變與降雨的迅速增強是亞洲夏季季風肇始的明顯特徵,除季節變化影響外,季內振盪低值到達時間亦是關鍵。本研究的目的即在分析季內振盪與季風環流之互動關係。並探討台大波普模式(NTU GCM)模擬亞洲季風區內季內振盪與季風環流之動力關係,我們採用Daubechies(1988)之波列轉換進行濾波,因其在處理區域性波動時能會保有原波動的區域性特徵。結果顯示,夏季熱帶地區出現三個強對流,分別在印度西岸、孟加拉灣與南海地區,其中南海地區的OLR變化主要是以30~60天波動為主。南海地區氣候平均值在五月中突然下降,30~60天振盪負值亦在相同時間由赤道向北傳遞,南亞高壓北移、南海高層風場反轉與30~60天振盪負值到達時間一致。此外,南海季內振盪可能是影響南亞高壓北移與高層東風的重要因素。NTU GCM模式可以模擬東亞夏季季風之爆發性突變,而模擬之季風肇始與模擬之30~60 天波動北傳的關係密切。NTU GCM所模擬之高壓北移、南海高層風場反轉時間亦與30~60天振盪負值到達時間一致。此結果顯示,以氣候平均觀點,模式中季內振盪之結構與與季風環流之間動力連結一致。
為探討東亞季風與東太平洋海平面溫度之相互關係,我們根據Nino3地區6~8月海溫距平區分SST冷年及SST暖年,結果顯示Nino3地區海溫與南海地區對流,無論在強度或肇始時間皆呈負相關,即在SST暖年,南海地區對流發生時間延遲,對流強度減弱,而其影響直接反應在30~60天振盪上。此外,受到OLR呈南北振盪的影響,長江流域(日本)與Nino3地區海溫呈正(負)相關。模式模擬之季風肇始在SST冷年較SST暖年早,與實際相符,且模式在SST冷年之OLR 及30~60天振盪均較SST年強,顯示模式在南海季風之季風肇始及強度的年際變化,確實受到模式本身之30~60 天振盪影響。
參考文獻
Chen, T.-C., and Chen, J.-M., 1995: An observational study of the South China Sea monsoon during the 1979 summer: Onset and life cycle. Mon. Wea. Rev., 123, 2295-2318.
Daubechies, I., 1988: Orthonormal bases of compactly supported wavelets. Commun. Pure Appl. Math., 41, 909-996.
He, H., J. W. McGinnis, Z. Song, and M. Yanai, 1987: Onset of the Asian monsoon in 1979 and the effect of the Tibetan Plateau. Mon. Wea. Rev., 115, 1966-1995.
Kau, W. S., 1998: The NTUGCM’s AMIP Simulation on the East Asian Summer Monsoon, TAO ,Vol., 9, No. 2, 197-238, June 1998.
Krishnamurti, T. N., and D. Subrahmanyam, 1982: The 30-50 day mode at 850 mb during MONEX. J. Atmos. Sci., 39, 2088-2095.
Lau, K.-M., and Yang S., 1996: Seasonal variation, abrupt transition, and intraseasonal variability associated with the Asian summer monsoon in the GLA GCM. J. Climate, 9, 965-985.
Madden, R. A., and P. R. Julian, 1971: Detection of a 40-50 day oscillation in the tropical Pacific. J. Atmos. Sci., 28, 702-708.
Madden, R. A. and P. R. Julian, 1972: Description of global scale circulation cells in the tropics with 40-50 day period. J. Atmos. Sci., 29, 1109-1123.
Mak, M., 1995: Orthogonal Wavelet analysis: Interannual variability in the sea surface temperature. Bull. Amer. Meteor. Soc., 76, 2179-2186.
Ou ,S. C. and K. N. Liou 1988: Development of radiation and cloud parameterization programs for AFGL global models. Report No. AFGL_TR-88-00181, Air Force Geophysics Laboratory, Hanscom Air Force Base, Massachusetles, 88pp.
Sligo JM, Sperber KR, Boyle JS, Ceron J-P, Dix M, Dugas B, Ebisuzaki W, Fyfe J, Gregory D, Gueremy J-F, Hack J, Harzallah A, Inness P, Kitoh A, Lau WK-M, McAvaney B, Madden R, Mattews A, Palmer TN, Park C-k, Randall D, Renno, 1995: Atmosphere Model Intercomparison Project (AMIP) intraseasonal oscillations in 15 atmosphere general circullation models. WCRP-88 WMO/TD-No.661.
Sligo JM, Sperber KR, Boyle JS, Ceron J-P, Dix M, Dugas B, Ebisuzaki W, Fyfe J, Gregory D, Gueremy J-F, Hack J, Harzallah A, Inness P, Kitoh A, Lau WK-M, McAvaney B, Madden R, Mattews A, Palmer TN, Park C-k, Randall D, Renno, 1996: Atmosphere Model Intercomparison Project (AMIP) intraseasonal oscillations in 15 atmosphere general circullation models. Clim Dyn, 12, 325-357.
Wang, B., and H. Rui, 1990: Synoptic climatology of transient tropical intraseasonal convection anomalies. Meteor. Atmos. Phys., 44, 43-61.
--------, and Y. Ding 1992: An overview of the Madden-Julian oscillation and its relation to monsoon and mid-latitude circulation .Advances Atmos Sci, 9, 93-111.
---------, and Zhen Fan., Choice of south Asian summer monsoon indices. Submitted to Bulletin of AMS,June 1998.
Webster., P, J., and S. Yang 1992: Monsoon and ENSO: Selective interactive systems. Quart. J. Roy. Meter. Soc., 118, 877-926.
Weng., H., and K.-M. Lau, 1994: Wavelets, period doubling, and time-frequency localization with application to organization of convection over the tropical western Pacific. Mon. Wea. Rew., 121, 2523-2541.
Yasunari, T., 1979: Cloudiness fluctuations associated with the northern hemisphere summer monsoon. J. Meter. Soc. Japan, 57, 227-242.