The Interdecadal Abrupt Change of the African-Asian Summer Monsoon in the 1960s
60年代亚非夏季风十年尺度的突变

On the basis of comprehensive analyses of recent climatic data, it exposes a decadal abrupt change of African-Asian Summer Monsoon in the 1960s. The results indicate that, before its abrupt change, surface temperature presents positive anomalies over the African-Asian continents, and negative anomalies over the indian Ocean and the western Pacific Ocean. Therefore, the ocean-continent thermal contrast increased. Correspondingly, it is inversed after the abrupt change. On the surface pressure fields, a strongly warm low center over the African-Asian continents weakens through the abrupt change. Simultaneously, strong African and East Asian monsoon in summer weakens significantly. Results show that the East Asian monsoon, the indian monsoon and the North African monsoon change synchronously. The most remarkable feature of this abrupt change is that in arid and semi-arid belt, from the North African Sahara-Sahel to the Middle East, North india and North China, rainfall changes abruptly from abundent to seldom. The opposite trend happens on the two sides of this belt.