摘要
对比分析夏季发生在长江全流域两次特大洪涝的１９５４ 年和１９９８ 年大尺度环流的特征。指出１９５４ 年西北太平洋副热带高压第二次季节性北跳明显偏迟，出现在８月初，６～７ 月副高位置持续偏南，８ 月副高位置偏北；而１９９８ 年副高第二次季节性北跳偏早，出现在７ 月上旬中期，但盛夏７ 月下旬～８ 月底副高位置持续偏南。这两年夏季亚洲西风带阻塞高压活动都十分频繁，１９９８ 年更甚。夏季赤道辐合带１９９８ 年明显弱于１９５４ 年。
The large scale circulation characteristics in summer between 1998 and 1954 were comparied.Both years happened catastropic flood in the whole Yangtze River valley since the 20th century.The results of analysis show that the second seasonal jumping northward of subtropical high over the north west Pacific had been obviously postponed in 1954, which appeared in early August.And subtropical high was unusually southward than normal from June to July.Nevertheless,its seasonal jumping northward was advanced in 1998, which appeared in early July, and the subtropical high was further south persistently than normal from the third dekad of July to the end of August.At the same time, ITCZ of summer was notably weaker in 1998 than in 1954.But the action of blocking high of the westerly belt in Asia was very frequently in summer of the both years, especially in 1998.
出处
《气象》
CSCD
北大核心
2000年第1期38-42,共5页
Meteorological Monthly
