亚洲夏季风结构和变动与大气运动的斜压和正压特征:斜压模分析

通过定义流场的斜压性度量参量，利用观测资料，对大气运动的斜压特征量与夏季风变动的联系进行了探讨。结果表明：夏季风流场具有较强的斜压性；纬向气流的斜压强弱的时间变动与夏季风进退相吻合；强斜压区的范围可反映夏季风活动的基本范围。经向斜压运动强弱的水平分布及时间－经度剖面上斜压运动动能的纬向传播都与亚洲季风体系中季风子系统有关

THE STRUCTURE AND VARIATIONS OF ASIAN SUMMER MONSOON REVEALLED BY BAROTROPIC AND BAROCLINIC MODES:THE BAROCLINIC MODE ANALYSIS

A formula for measuring the baroclinicity of the atmosphere has been defined in this paper. By using the observational data, the relationships between the baroclinic mode of the atmosphere and the spacial structure and time evolution of Asian summer monsoon have been investigated. It is pointed out that there exist a strong baroclinic component in wind field during summertime. The time variations of the intensity of baroclinicity in zonal wind are in keeping with the timetable of the movements of monsoon. The area where the baroclinic wind is stronger can be used to determine the monsoon region basically . The horizontal distribution of baroclinicity of meridional wind component and the zonal propagation of baroclinic disturbances in time longitude cross section are both related to subsystems of the Asian summer monsoon regimes.