【类型】期刊
【题名】江淮流域夏季严重旱涝与大气季节内振荡
【作者】 YANG Hui LI Chongyin
【关键词】 ISO in 季节内振荡 pattern Huaihe Changjiang 大气ISO环流型 intraseasonal flood summer the drought 江淮流域夏季严重旱涝 Basin and circulation severe oscillation River
【期刊名】大气科学进展
【摘要】The intraseasonal oscillation (ISO) is studied during the severe flood and drought years of theChangjiang-Huaihe River Basin with the NCEP/NCAR reanalysis data and the precipitation data inChina. The results show that the upper-level (200 hPa) ISO pattern for severe flood (drought) is charac-terized by an anticyclonic (cyclonic) circulation over the southern Tibetan Plateau and a cyclonic (anti-cyclonic) circulation over the northern Tibetan Plateau. The lower-level (850 hPa) ISO pattern is char-acterized by an anticyclonic (cyclonic) circulation over the area south of the Changjiang River, the SouthChina Sea, and the Western Pacific, and a cyclonic (anticyclonic) circulation from the area north of theChangjiang River to Japan. These low-level ISO circulation patterns are the first modes of the ISO windfield according to the vector EOF expansion with stronger amplitude of the EOF1 time coefficient in se-vere flood years than in severe drought years. The analyses also reveal that at 500 hPa and 200 hPa,the atmospheric ISO activity over the Changjiang-Huaihe River basin, North China, and the middle-highlatitudes north of China is stronger for severe flood than for severe drought. The ISO meridional windover the middle-high latitude regions can propagate southwards and meet with the northward propagatingISO meridional wind from lower latitude regions over the Changjiang-Huaihe River Basin during severeflood years, but not during severe drought years.
【年份】2003
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