The Modon Blocking High in Asia and Meiyu in the Yangtze-Huaihe Area
亚洲偶极子阻高与江淮梅雨

This paper discusses the climatic characteristics of the modon and soliton blocking high with the blocking index counted by daily geopotential height on 500 hpa from June to July in 1971-1991 in Asia.The results show that modon block is the main circulation of westerly belt in the Meiyu seasons and that anomalous activity of the modon effect on the catastrophic flood in the Yangtze-Huaihe area in 1991.In addition, the effects of the characteristics of the meridional circulation on precipitation in the Mei-yu seasion have been preliminarily studied.