定常波和瞬变波在亚洲季风区大气水分循环中的作用

ROLE OF THE STANDING AND THE TRANSIENT EDDIES IN ATMOSPHERIC WATER CYCLE IN THE ASIAN MONSOON REGION

中文关键词:  水汽输送  定常涡动  瞬变涡动  季风经圈环流  水汽源(汇)

英文关键词:Water vapor transport  Standing eddies  Transient eddies  Meridional Monsoon Circulation  Moisture source (sink)

中文摘要:

      利用欧洲中心ECMWF10a逐日资料,对定常波和瞬变波在亚洲季风区大气水分循环中的作用进行了计算分析。结果表明,瞬变涡动总把水汽从高水汽含量区送到低水汽含量区,实现与平均环流相反的输送,维持了热带地区和中高纬地区水汽的平衡。夏季定常涡动输送的经向分量是将水汽从热带向副热带输送的主要机制,而瞬变涡动输送的经向分量则是把水汽从副热带输送到中高纬的主要机制。由于季风经圈环流的存在,使得亚洲季风区的热带地区为重要的水汽源区,而其副热带和中纬度地区是水汽汇区,这与同纬度其它地区相反。

英文摘要:

      Using ECMWF daily data from 1980-1989, analyses are conducted concerning the role of the standing eddies (SE) and the transient eddies (TE) in transporting water vapor in the Asian monsoon region. Results show that the TE always transport water vapor along the moisture gradient, so that equilibrium of vapor content in tropical belts and middle and high latitudes can be maintained. In summer water vapor transport by the SE is responsible for water vapor flow from tropical to subtropical area, while water vapor transport by the TE is the main mechanism for water vapor flow from subtropical latitudes to middle and high latitudes. Due to the existence of the Meridional Monsoon Circulation, tropical belts within the Asian monsoon region become moiture sources and extratropical belts become moisture sinks. This feature is in reverse with other regions of similar geographic latitudes.