武汉地区“98.7”暴雨过程大气稳定性分析  

ATMOSPHERIC STABILITY ANALYSIS OF WUHAN RAINSTORM IN JULY 1998

作　　者：安洁[1] 张立凤[1] 

机构地区：[1]解放军理工大学气象学院,南京211101

出　　处：《应用气象学报》2005年第3期313-321,共9页Journal of Applied Meteorological Science

基　　金：国家重点基础研究发展规划项目"我国南方致洪暴雨监测与预测的理论和方法研究"(2004CB418300)资助。

摘　　要：文章从环境场的稳定性角度进行研究,取boussinesq近似的二维数学模型,从数值模式每小时输出的预报场中提取暴雨过程中的环境场,通过计算函数极小值的方法,求取层结参数及加热率,讨论实际暴雨过程中不稳定的作用。其结果表明,凝结加热对暴雨不稳定的发生发展作用明显。暴雨初期和强盛期的环境场都可以出现动力不稳定,且不稳定扰动传播方向与基本气流有一个斜交角,属于二维平面波的不稳定。“98.7”暴雨的发生发展是热力和动力共同作用的结果。In terms of the stability of the background field, a 2D Boussinesq approximation model is adopted, and from the prognostic field exported by the model on an hourly basis a background field during the rainstorm is taken, followed by the method for minimum of the function to get a stratification parameter and heating rate, with which to discuss the role of unstable disturbance during the rainfall. Evidence suggests that heat released from condensation exerts distinct effects on the generation and development of rainstorm instability. At the early and prime stages the environmental field exhibits dynamically instable disturbance that propagates at a small angle with basic flow, i.e., instability of 2D plane wave. The torrential rain occurs under the joint action of the thermal and dynamic factors.

关 键 词：暴雨过程 稳定性分析 武汉地区 boussinesq近似 大气 二维数学模型 发生发展 动力不稳定 环境场 数值模式 计算函数 凝结加热 基本气流 传播方向 稳定扰动 共同作用 预报场 极小值 加热率 斜交角 平面波 小时 层结 

分 类 号：P458.121.1[天文地球—大气科学及气象学] P731.27