一次华北锋面带状降水过程中的对流-对称不稳定诊断分析  

Diagnostic Analysis of Convective-Symmetric Instability During a Banded Precipitation Process in North China

作　　者：王晨曦 邓莲堂[2] 范广洲 李泽椿 周定文 WANG Chenxi;DENG Liantang;FAN Guangzhou;LI Zechun;ZHOU Dingwen(Sichuan Meteorological Disasters Prevention Technology Center, Chengdu 610072;Numerical Weather Prediction Centre, CMA, Beijing 100081;Key Laboratory of Plateau Atmospheric and Environment in Sichuan Province, College of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225;National Meteorological Centre, Beijing 100081;Nuclear Power Institute of China, CNNC, Chengdu 610005)

机构地区：[1]四川省气象灾害防御技术中心,成都610072 [2]中国气象局数值预报中心,北京100081 [3]成都信息工程大学大气科学学院高原大气与环境四川省重点实验室,成都610225 [4]国家气象中心,北京100081 [5]中国核动力研究设计院,成都610233

出　　处：《气象》2018年第12期1518-1528,共11页Meteorological Monthly

基　　金：国家自然科学基金项目(41275103;41505093);国家重点基础研究发展计划(2013CB430106);国家重点研发计划(2017YFC1502001)共同资助

摘　　要：本文用GRAPES_Meso中尺度区域模式模拟了2015年8月2—4日的一次华北锋面带状降水过程,在模拟结果与实况比较吻合的情况下,用高分辨率模式输出资料对降水过程中的对流稳定度、惯性稳定度和条件性对称不稳定(CSI)进行了分析,并诊断出降水过程中的条件性对称不稳定区域。个例分析的结果表明:(1)带状降水过程中CSI的发展伴随着对流不稳定的减弱和惯性不稳定的增强。(2)根据不稳定量的变化情况,把降水过程分为3个阶段:在第一个阶段,降水区域上空-?θ_e/?p<0,降水主要受对流不稳定的影响;在第二个阶段,对流不稳定、惯性不稳定与CSI发展增强,此阶段的降水受3种不稳定量的影响;在第三个阶段,3种不稳定能量均逐渐减弱,但仍然影响着降水的持续。(3)发展旺盛阶段的CSI在平面上呈带状分布,与雨带、对流不稳定区域平行,在剖面上CSI主要活跃在对流层低层。(4)用湿位涡结合对流稳定度与惯性稳定度诊断CSI区域的方法比M-θ_e剖面图方法更准确有效。Using the mesoscale regional model GRAPES_Meso, this paper simulates a frontal rain band which occurred in North China during August 2-4 2015. The simulated results are in good agreement with the observations. The convective stability, inertial stability and conditionally symmetric instability (CSI) during the precipitation process are analyzed using the model output data, and the CSI region is diagnosed. The results show that: (1) The development of CSI was accompanied by the weakening of convective instability and the enhancement of inertial instability. (2) According to the change of instability, the precipitation is divided into three stages. In the first stage, the precipitation was mainly affected by convective instability; in the second stage, convective instability, inertial instability and CSI got enhanced, and precipitation at this stage was affected by three types of instability; in the third stage, the three types of instability gradually weakened, but still affected the sustainability of precipitation. (3) In the vigorous developing stage, CSI showed a band like distribution in the plane. In the profile, the CSI is active in the lower troposphere. (4) In diagnosing CSI, the method with MPV and convective instability is more effective than the one with M-θe.

关 键 词：GRAPES-Meso 锋面雨带 对流不稳定 条件性对称不稳定(CSI) 

分 类 号：P458.121[天文地球—大气科学及气象学]