江淮气旋发生发展中尺度系统特征数值模拟研究

本文应用中尺度模式MM5对发生在江淮流域的气旋进行了数值模拟，并用模式输出的高时空分辨率、动力协调资料、HUBEX试验期间的加密观测资料进行江淮气旋的中尺度诊断研究。结果表明：从大尺度角度看，江淮气旋的生成可分为静止锋上的波动和倒槽锋生两种类型，但从中尺度角度分析，它们具有如下共同特点：（1）它们的生成源地均在大别山西侧，大别山地形均使得气旋发展增强，移速减慢。（2）在发展阶段，700hPa层以下的温压场的斜压结构是气旋发展的重要因素，当冷平流与暖平流呈现西北－东南的偶极子型时，气旋发展；当冷暖平流偶极子呈东西型时，气旋发展进入成熟期。（3）气旋中的中尺度雨带与Wave-CISK湿条件对称不稳定区有密切关系，辐合上升区出现在气旋暖锋前部和冷锋后部50－100km范围内。

THE NUMERICAL SIMULATING STUDY OF THE MESOSCALE CHARACTERISTICS ON DEVELOPMENT OF JIANG-HUAI CYCLONES

In this paper,the mesoscale numerical model MM5 was used to simulate the development of Jiang-Huai Cyclones.The hourly model outputs with high spatial and temperal resolution and the HUBEX data during the IOP were then used for detailed diagnostic studies of the mesoscale systems within Jiang-Huai Cyclones.The following results were showed: (1)Besides the effect of forcing lifted,the major effect of the Dabi Mountain on the Jiang-Huai Cyclones is that the topography induces the temperature differential advection and causes increasing of the instability and the cyclone's development. (2)The asymmetrical structure of the middle & low level cold and warm advection is the important factor for cyclone's development.The cyclone is in deceloping stage when the axis of the dipole is oriented in north-west to south-east direction,while it reached its mature when the dipole is oriented in east-west direction. (3)Wave-CISK CSI may be an important mechanism to cause the inner meso-scale rain-belts in cyclone.The unstable area occurred in the area 50-100 km ahead of the warm front and behind of the cold front.