【摘要】 本文利用1980—1983年7月 ECMWF 资料,分析了夏季热带地区经向环流的结构及它们的区域和年际差异。指出夏季热带经向环流具有双圈结构。在季风区,对流层下部为季风环流,在非季风区,为 Hadley 环流;对流层上部存在一独立的环流圈,季风区的中心偏北半球,非季风区的中心偏南半球;热带经向环流的双圈结构在一般年份均存在,但在异常年份(1983年),强大的垂直运动将对流层上、下部两个相对独立的环流圈紧密连接起来,成为整层统一的大范围季风环流。更多还原

【Abstract】 The structure of tropical meridional circulation in summer and its regional differences andinterannual variations are studied by using the July 1980—1983 ECMWF data.It is found thatthe tropical meridional circulations show a two-cell structure.In the lower troposphere,there are monsoon circulations in the monsoon region and Hadley circulations in the non-monsoon region;while in the upper troposphere,there is an independent circulation in both monsoon and non-mon-soon regions,with its center located in the Northern Hemisphere for monsoon region and in theSouthern Hemisphere for non-monsoon region.This two-cell structure always exists in normalyears.However,in the abnormal year(1983),the circulation in the upper troposphere is muchweaker and can hardly be recognized,and the strong vertical motion results in a one-cell merid-ional circulation throughout the troposphere.更多还原