文章提出一种对流层低层季风定义的新方法。通过大量的资料分析,作者认为:对流层低层的风可以近似地看作是二部分的线性组合。一部分是非季风的行星风,这部分代表大气对海陆地形的动力强迫的响应;另一部分则是季风,这部分是大气对海陆地形的热力强迫响应。作者用多年平均的年平均风来代表行星风,这样分离出来的季风与经典季风相比有很多优点:1.计算简单;2.物理图象清楚;3.便于划分季风区。

In this paper, a new definition of the monsoon in the lower troposphere has been presented. Upon analysing the global cli-matic data of GFDL, it is found that the monthly mean horizontal wind system in the lower troposphere can be considered as the linear combination of two parts. The first part is the annual mean wind system which represents the atmospheric res-ponse to the orographically induced large scale statioary disturbances. The second part is the departure wind (monthly mean wind minus annual mean wind) which represents the atmos-pheric response to the heating contrast between oceans oceans and continents’ including large scale orography, i.e. the monsoon. Unlike classical definition, the above defined monsoon wind systems have clear physical interpretation, and have been conveniently used in the meteorological analysis.