正压大气动能梯度与地转偏差的关系及其对暴雨的诊断  

Relation between kinetic energy gradient and geostrophic deviation in barotropic atmosphere and diagnosis of torrential rain

作　　者：于杰[1,2,3] 张继权 朱娟[2,4] 张铭[2] 

机构地区：[1]东北师范大学环境学院 [2]解放军理工大学全军危险性天气监测预警研究中心/气象海洋学院 [3]解放军65301部队 [4]海洋环境专项办公室

出　　处：《气象科学》2017年第2期265-271,共7页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(41371495;41375063);国家科技支撑计划项目(2013BAk05B01)

摘　　要：本文从正压大气原始方程组出发,分析了不同尺度天气系统中动能梯度与地转偏差之间的关系。结果表明:在天气尺度和α中尺度运动中,动能梯度的模与地转偏差的模大致成正比。对天气尺度该比例系数为地转参数,且与运动本身无关。对较小尺度天气系统,该比例系数与运动本身密切相关。在β中尺度运动中,动能梯度的模小于等于两项之和,两项中的第一项与地转偏差的模成比例,第二项则是地转偏差时间导数的模。在动能梯度的高值区,运动的非平衡性和暴发性强。本文还以上海"08.8.25"暴雨过程为例,对500 hPa上的动能梯度做了诊断,发现动能梯度大值区与强降水的分布有很好的对应关系,并与以上理论分析相一致,这对暴雨等灾害性天气预报具有应用价值。The primary barotropic atmospheric equations of motion were used to analyze the relationship between the horizontal kinetic energy gradient and geostrophic deviation of different weather scales systems.Results show that for atmospheric motions of synoptic scale and meso-α scale,the value of horizontal kinetic energy gradient is approximately proportional to the value of geostrophic deviation.The proportional coefficient for synoptic scale motion is geostrophic coefficient,which is independent on motion characteristics,while for smaller scale atmospheric motion,it is closely related to motion characteristics.For atmospheric motions of meso-β scale,the value of horizontal kinetic energy gradient amounts to less than the sum of the two terms,in which the first one 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 ofkinetic energy gradient,the nonequilibrium behavior and outbreak behavior of atmospheric motion are striking.The diagnostic analysis on horizontal kinetic energy gradient was investigated by using the simulation data of a torrential rain occurring on Aug.25,2008 in Shanghai,which indicated that a quite good corresponding relationship exists between areas with maximum value of kinetic energy gradient and areas with strong precipitation,and it agrees consistent with the theoretical analysis.The diagnostic analysis on horizontal kinetic energy gradient is useful for torrential rain forecast and treatment of disaster weather.

关 键 词：动能梯度 地转偏差 诊断分析 暴雨 

分 类 号：P458.121.1[天文地球—大气科学及气象学]