一次东北暖锋锋生暴雨的中尺度特征分析及成因初探  

Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China

作　　者：任丽[1] 孙磊[2] 张桂华[1] 白雪梅[1] 张天华 REN Li;SUN Lei;ZHANG Guihua;BAI Xuemei;ZHANG Tianhua(Heilongjiang Provincial Meteorological Observatory, Harbin 150030;Suihua Meteorological Bureau of Heilongjiang Province, Suihua 152002)

机构地区：[1]黑龙江省气象台,哈尔滨150030 [2]黑龙江省绥化市气象局,绥化152002

出　　处：《暴雨灾害》2019年第4期311-319,共9页Torrential Rain and Disasters

基　　金：黑龙江省自然科学基金联合引导项目(LH2019D016);黑龙江省龙云气象科技有限责任公司气象院士工作站重点项目(YSZD201702);黑龙江省科技厅省院合作项目(YS18Z01);中国气象局预报员专项(CMAYBY2019-033)

摘　　要：使用常规观测资料、卫星云图、雷达回波资料、自动气象站降水量以及0.25°×0.25°的NCEP/NCAR再分析资料,对2017年8月1日发生在黑龙江南部的暖区暴雨过程的中尺度特征及成因进行了分析。结果表明:暴雨发生在副高加强西伸北抬及有台风活动的背景下,副高外围的水汽输送为暴雨提供了充沛的水汽条件;低层西南风的增大导致暖锋锋生,暖锋的辐合抬升作用加强,造成较大范围的暴雨天气;锋生区附近存在CSI,锋生作用及CSI的释放,加强了沿着锋面倾斜向上的斜升气流及锋面次级环流,CSI导致的斜升气流的发展进一步触发对流不稳定,导致大范围的垂直上升运动,降水显著加强;暖锋云带内部探空分析显示大气处于不稳定状态,有利于以短时强降水为主的对流发展。暴雨是由云团的后向传播造成的,强降水以暖云降水为主,降水效率高,雨强大,暖锋稳定少动,由暖锋锋生所致的对流单体在同一区域重复新生,并沿暖锋自西向东传播,形成列车效应,暴雨中心一直有最大反射率因子超过45 d Bz且降水效率高的强回波活动,持续时间超过4 h,导致强降水持续时间长,降水累积量大。Based on conventional observation data, satellite images, automatic observational data of precipitation and NCEP/NCAR reanalysis data(0.25°×0.25°), the mesoscale characteristics of a rainstorm caused by warm front frontogenesis were analyzed, and the cause of the rainstorm was preliminarily discussed. The major conclusions were as follow. The rainstorm occurred under the condition of the strengthening and westward-stretching subtropical high and the influence of typhoon activity. Water vapor transport on the periphery of the subtropical high pressure provided abundant water vapor conditions for rainstorms. The increase of the lower southwest wind led to the warm front, strengthened the convergence and uplift of the warm front, and caused a large area of rainstorm weather. There existed the conditional symmetric instability(CSI) in the frontogenetical area. The frontogenetical effect and the release of CSI strengthened the oblique upward flow along the frontal surface and the frontal secondary circulation. The developments of slantwise convection by CSI further triggered the convective instability. The convective instability led to a large area of vertical ascending motion, and the precipitation was significantly enhanced. The sounding analysis showed that the atmosphere of warm front cloud belt was in an unstable state, which was advantageous to the convection development with short time heavy rainfall. The rainstorm was produced by the β mesoscale finger cloud. The mesoscale cloud had the characteristics of backward propagation, which was caused by the rebirth and merging of convective clouds. Heavy precipitation was mainly composed of warm cloud precipitation, high precipitation efficiency and heavy rain. The warm front was stable and less active, and the convective cell caused by warm front was repeated in the same region, and traveled along the warm front from west to east to form the train effect. The strong echo activity of the rainstorm center had a high precipitation efficiency exceeding 4 hours(maxim

关 键 词：暖锋 锋生 条件对称不稳定(CSI) 次级环流 中尺度对流系统(MCS) 台风 

分 类 号：P458.121.1[天文地球—大气科学及气象学]