摘要
2005年7月9～10日湖北西部-河南南部出现了一次强降水过程。从天气形势的发展变化，推断出天气系统演变过程的两种可能方式，然后用中尺度数值模式AREM对这次强降水过程进行了数值模拟，在模拟结果的基础上分析了暴雨发展的中尺度过程和特征。这次过程是由辐合线加强和气旋发展两个阶段组成的，在辐合线加强过程中，随着辐合线北侧下空气的南侵以及暖湿空气南南至北倾斜向上发展．上升运动发展到对流层高层后向南北两侧辐散，并在对流层中层构成一对经阳偶极子环流圈，它们的下沉支补偿融入上升运动区中，加强和维持了低层的辐合；而在气旋发展过程中，切变线南侧的湿空气明显向北发展，并在切变线上跨越湿度锋区新生发展出一个β中尺度气旋，气旋南半部的湿空气具有强辐合性并伴有强上升运动发展，紧邻其南侧是湿补偿下沉气流，而上升运动北侧的干下沉气流一直向下伸展到边界层顶附近，受低层湿空气向北发展穿越湿度锋区的作用没有向南融入上升运动区中，文中最后给出了辐合线加强和气旋发展的三维空间结构示意图。
A heavy rain event occurred in the area from western Hubei to southern Henan during 9-10 July 2005. According to the development process of the weather, two possible weather evolvement modes are deduced. Based on the simulated result by the mesoscale heavy rainfall prediction model （AREM）, the mesoscale process and feature are analyzed. This process consists of convergence line inhancement and cyclone development. During the dry and cold air intrusion process, along with the dry air intruding towards south and the warm-wet air inclining upwards from north to south and developing, the ascending movement develops to the troposphere then diverges to the south and the north. Thus a meridional dipole circulation is formed in the middle of troposphere. The sinking movement compensates and joins to the rising movement, which enhances and maintains the low convergence. During the cyclone development, the wet air in the south of the shear line develops towards north obviously, then a new meso-β-scale cyclone forms on the shear line. The south wet air of the cyclone converges intensity and rises. The dry sinking airflow which lies in the north of ascending movement extends downwards near to the top of boundary layer, but it does not join to the rising airflow because of the action of low wet air developing towards north and through the wet front. In the end of this paper, the three- dimensional special frame schematic diagram is given.
出处
《高原气象》
CSCD
北大核心
2008年第3期558-566,共9页
Plateau Meteorology
基金
国家自然科学基金项目(40575029)
湖北省自然科学基金项目(CGZ0036)共同资助
关键词
暴雨过程
数值模拟
β中尺度气旋
辐合线
湿空气发展
Heavy rain process
Numerical simulation
Meso-β scale cyclone
Convergence line
Cyclone development
