多层模式中动能水平梯度的性质及诊断  

Properties and diagnose of horizontal kinetic energy gradientin multilevel model

作　　者：朱娟[1,2] 于杰[1,3,4] 张铭[1] 

机构地区：[1]全军危险性天气监测预警研究中心解放军理工大学气象海洋学院,南京211101 [2]中国人民解放军海洋环境专项办公室,北京100081 [3]东北师范大学环境学院,长春130021 [4]解放军65301部队,长春130022

出　　处：《暴雨灾害》2017年第3期267-275,共9页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(41375063)

摘　　要：从多层原始方程组出发,分析了不同尺度天气系统各层的动能水平梯度与该层地转偏差之间的关系,并对南京2010年7月22日暴雨过程的动能水平梯度模进行了诊断。结果表明:在天气尺度和α中尺度系统中,各层动能水平梯度模与该层地转偏差的模大致成正比。对天气尺度系统,该比例系数为地转参数,与该系统本身无关。对α中尺度系统,该比例系数与该系统本身有关。在β中尺度系统中,各层动能水平梯度模小于等于两项之和,而这两项中第一项与地转偏差的模成正比,另一项则为地转偏差时间导数的模。动能水平梯度大值区运动的非平衡性和爆发性强。在暴雨落区和飑线上,各层动能水平梯度的模均较大。通过对动能水平梯度模的诊断,能够从风场角度来分析各尺度系统,这对中尺度系统的诊断分析尤为重要。Based on multilevel primary equations of motion, the relations between the horizontal kinetic energy gradient at each level and the corresponding geostrophic deviation of weather systems over different scales are obtained. The diagnostic analysis on horizontal kinetic energy gradient of the rainstorm on July 22, 2010 in Nanjing are carried out. The main results are as follows. For atmospheric systems of synoptic scale and meso-α scale, the value of horizontal kinetic energy gradient is approximately proportional to the value of geostrophic deviation at each level. The proportional coefficient for the system of synoptic scale is the geostrophic coefficient, and independent of the system. While the proportional coefficient for a smaller scale atmospheric system is closely related to the system. For atmospheric system of meso-β scale, the value of horizontal kinetic energy gradient is less than the sum of two terms at each level. The first term is proportional to the value of geostrophic deviation and the second one is the value of the time derivative of geostrophic deviation. In the high value area of horizontal kinetic energy gradient, the nonequilibrium behavior and outbreak behavior of atmospheric motion are strong. The values of kinetic energy gradient at each level over precipitation areas and squall line are greater. The analysis of the magnitude of kinetic energy gradient makes it possible to diagnose and analyze atmosphere systems of various scales in wind field terms, which is important to the diagnostic analysis of meso scale systems.

关 键 词：诊断分析 多层原始方程组 动能水平梯度 地转偏差 

分 类 号：P433[天文地球—大气科学及气象学]