The role of the intraseasonal oscillation (ISO) on the seasonal and interannual variations of the Indian summer monsoon is investigated based on the analysis of observational data. It is shown that the ISO significant...The role of the intraseasonal oscillation (ISO) on the seasonal and interannual variations of the Indian summer monsoon is investigated based on the analysis of observational data. It is shown that the ISO significantly contributes to the establishment of low-level westerlies during the monsoon onset and developing periods. The effect of the ISO on the annual cycle of the monsoon is through nonlinear eddy momentum transport. On the interannual timescale, the Indian summer monsoon rainfall exhibits a significant out-of-phase relationship with the ISO intensity over the Indian monsoon region. In strong ISO years it appears the weak monsoon when there is an abnormal high over the India subcontinent in the lower troposphere. In weak ISO years there exists an abnormal low and the strong monsoon ap-pears.展开更多
用奇异值分解(Singular Value Decomposition,SVD)方法,给出了四季年代际和年际时间尺度上北大西洋和北太平洋海表温度(Sea Surface Temperature,SST)的显著遥相关。用SVD主模态时间系数构造了海温异常指数I,分析了它们与同期亚太夏季...用奇异值分解(Singular Value Decomposition,SVD)方法,给出了四季年代际和年际时间尺度上北大西洋和北太平洋海表温度(Sea Surface Temperature,SST)的显著遥相关。用SVD主模态时间系数构造了海温异常指数I,分析了它们与同期亚太夏季风和我国东部夏季降水异常的关系。结果表明:两大洋间的SST遥联在年际、年代际时间尺度上都与亚太夏季风相关,其中,年际尺度的两大洋SST遥联与长江流域的降水存在显著相关。展开更多
基金Supported by National Basic Research Program of China (Grant No. 2006CB403602)National Natural Science Foundation of China (Grant Nos. 40225012 and 40775039)Chinese COPES Program (Grant No. GYHY200706005)
文摘The role of the intraseasonal oscillation (ISO) on the seasonal and interannual variations of the Indian summer monsoon is investigated based on the analysis of observational data. It is shown that the ISO significantly contributes to the establishment of low-level westerlies during the monsoon onset and developing periods. The effect of the ISO on the annual cycle of the monsoon is through nonlinear eddy momentum transport. On the interannual timescale, the Indian summer monsoon rainfall exhibits a significant out-of-phase relationship with the ISO intensity over the Indian monsoon region. In strong ISO years it appears the weak monsoon when there is an abnormal high over the India subcontinent in the lower troposphere. In weak ISO years there exists an abnormal low and the strong monsoon ap-pears.
文摘用奇异值分解(Singular Value Decomposition,SVD)方法,给出了四季年代际和年际时间尺度上北大西洋和北太平洋海表温度(Sea Surface Temperature,SST)的显著遥相关。用SVD主模态时间系数构造了海温异常指数I,分析了它们与同期亚太夏季风和我国东部夏季降水异常的关系。结果表明:两大洋间的SST遥联在年际、年代际时间尺度上都与亚太夏季风相关,其中,年际尺度的两大洋SST遥联与长江流域的降水存在显著相关。
