河南省一次致灾强对流天气的中尺度分析  

Mesoscale Analysis of a Disastrous Severe Convective Weather over Henan

作　　者：王金兰 陈红霞 段中夏 乔雨 

机构地区：[1]新乡市气象局,河南新乡453003 [2]洛阳市气象局,河南洛阳471000

出　　处：《气象与环境科学》2014年第3期14-20,共7页Meteorological and Environmental Sciences

基　　金：河南省重点科技攻关计划项目(112102310033)资助

摘　　要：利用常规观测资料、中尺度分析产品和雷达资料对2013年8月1日凌晨发生在河南省西部、北部的一次致灾强对流天气过程进行分析。结果表明:这次强对流是在上干冷下暖湿的不稳定大气层结条件下产生的,较大的垂直风切变出现在强对流发生后,可能与强对流天气产生时间较晚有关;地面辐合线是这次强对流产生的触发机制,强对流发生在地面等温线和等露点线的密集区内。云图亮温的低值中心对应地面的强雨区。1日凌晨,对流回波东移加强,先后形成的两条弓形回波,均存在明显的低层弱回波区和中高层的悬垂回波结构,大风发生在弓形带状回波后侧;对流回波带低层有很强的西南风急流,使得强对流回波形成弓形带状回波;强回波带的前沿速度场上,有中尺度辐合线、辐合区、逆风区存在,它们的出现和维持是产生局地强降水的一个有用指标,中尺度系统的存在是强对流风暴产生、维持、发展的必要条件;较大垂直液态含水量的维持为产生强降水提供了有利条件,垂直液态含水量的增减,预示着地面强对流天气的开始和减弱。Based on conventional observational data, mesoscale analysis data and radar data, a dis- astrous severe convective weather process over the west and the north of Henan on the early morning of 1 August 2013 was analyzed. The results showed that： the severe convection is generated in the unstable convection stratification with cold dry top and warm moist bottom. Stronger vertical wind shear generated after the severe convection and may be associated with late occurrence of the severe convection. The ex- istence of the surface convergence line was the trigger of the strong convection which occurred in the dense area of isotherms and isodrosotherm. The low center of TBB was well corresponded with heavy rain- fall area. On August 1 morning, the convective echo was moving eastward and strengthening, and formed two bow-shaped echoes which had visual weak echo region in lower layer and overhang structure echo in middle and high. And the wind occurred at the rear of the bow echo. Strong low-level southwest jet made strong convective echo to be bow belt echo. The occurrence and maintenance of mesoscale convergence line, convergence zone, adverse wind area on the head velocity field of the strong echo were a useful in- dicator to generate local strong precipitation, and the existence of mesoscale system was a necessary con- dition for the generation, maintenance and development of strong convective storm. The maintenance of larger vertical integrated liquid （VIL） provided favorable conditions for the strong precipitation, and the increasing and decreasing of VIL was well connected with the starting and weakening of severe weather.

关 键 词：强对流 中尺度分析 雷达产品 垂直液态含水量 

分 类 号：P458.3[天文地球—大气科学及气象学]