青藏高原冬季积雪异常对东、南亚夏季风影响的初步数值模拟研究

利用一个耦合了简化的简单生物圈模式的大气环流谱模式（ＳＳｉＢ－ＧＣＭ），初步探讨了青藏高原冬季积雪异常对东、南亚夏季风环流和降水的影响及其机理。结果表明，高原地区冬季积雪增加将使随后的夏季东、南亚季风明显减弱，主要表现为东、南亚季风区降水减少，索马里急流、印度季风槽和印度西南气流减弱。另外，还提出欧亚大陆雪盖与整个高原雪盖和高原东部雪盖对东、南亚夏季风影响的敏感性问题。与欧亚大陆雪盖相比，高原雪盖是影响东、南亚季风的更敏感区，冬季高原以外雪盖增加，有可能使亚洲季风增强；当高原东部雪盖增加时，高原以东地区及印支半岛降水减少，印度东部、南部和孟加拉湾西北部降水反而增加

THE PRELIMINARY NUMERICAL EXPERIMENTS OF EFFECT OF ANOMALOUS SNOW COVER OVER PLATEAU IN WINTER ON EAST AND SOUTH ASIAN SUMMER MONSOON

A general circulation model, which has been coupled with the simple biosphere model,was used to assess the influence of anomalous Plateau snow cover in winter on the east and south Asian summer monsoon circulation and rainfall The results point out that the summer monsoon in the east and south Asia would be weakened when the winter snow cover over Plateau is increased The main features are that the precipitation is reduced in the east and south Asian summer monsoon region and the Somali jet,the Indian monsoon trough and the Indian southwest air flow are weakened In addition,we have also examined the sensitivity of the effects of the snow cover over the Eurasia and the east Plateau on the Asian monsoon It is found that the Plateau snow cover was more sensitive than that over Eurasia If only the east Plateau snow cover was increased,the precipitation in the east region of the Plateau, such as in east Asia,would be more reduced,but it might be increased in the area of the east and south India and the bay of Bengal