摘要
利用常规天气资料、多普勒雷达资料和区域自动气象站资料,对发生在济南的33次重大短时强降水过程进行总结分析。结果表明,重大短时强降水过程年均发生3. 3次,主要发生在7月上旬——8月中旬,17——23时和02——08时最易发生,南部山区较北部平原地区更易发生,且雨强更大。低槽冷锋型出现最多,水汽和动力条件充足,层结曲线中上层具有喇叭口型结构,对流有效位能呈瘦高状,平均值为1 370 J·kg^(-1),对流由冷锋触发(有时存在暖区对流),强降水范围最广;副热带高压边缘型水汽充沛,对流有效位能呈粗胖状,平均值为2 400 J·kg^(-1),对流由底层的动力系统触发,局地性和突发性强,强降水分布不均匀;低涡切变线型具有夜雨性,水汽较充沛,动力条件一般,对流有效位能平均值为607 J·kg^(-1)。低槽冷锋型和低涡切变线型平均雨强较大,副热带高压边缘型持续时间较长,低槽冷锋型能够产生平均雨强异常大或持续时间较长的过程,因此易出现极端降水事件。带状回波出现最多,主要由低槽冷锋型产生,块状回波主要由副热带高压边缘型产生,分布零散,絮状回波主要由低涡切变线型产生,强度较弱。强回波主要集中在中低层,回波整体质心偏低,呈现热带降水型特征。10次形成列车效应的过程中有7次由带状回波或短带回波的后向传播形成,另外3次由尺度较大的絮状回波形成,其持续时间和平均降水量是其余过程的两倍。
By using conventional observation data,Doppler radar data,and regional automatic weather station data,33 cases of short-time severe rainfall events happened in Jinan are analyzed and systematically summarized.The results show that the short-time severe rainfall occurred averagely 3.3 times per year,mainly occurred from early July to mid-August,and the most probable time is from 17:00 to 23:00 and from 02:00 to 08:00(local time).The short-time heavy precipitation is more likely to occur and has stronger intensity in the southern mountainous region than in the northern plains.The TypeⅠ(upper trough/cold front)severe rainfall events happen most frequently with plentiful vapor and favorable dynamic conditions.There is a flared structure in the middle and upper stratification curve,while the pattern of CAPE(convective available potential energy)is narrow with the average value of 1 370 J·kg^-1.The convections are mostly triggered by the cold front(sometimes the warm convection existed)and generate widespread severe rainfall.For the TypeⅡ(subtropical high edge)severe rainfall events,the water vapor supply is plentiful,the pattern of CAPE is wide with the average value of 2 400 J·kg^-1.The convections are usually triggered by the underlying dynamical systems locally and suddenly with unevenly distributed heavy rainfall.The TypeⅢ(low vortex/shear line)severe rainfall events often happen at night with plentiful water vapor supply,fairly good dynamic conditions,and averaged CAPE of 607 J·kg^-1.For these different types of severe rainfalls,the average rainfall intensity of TypeⅠor TypeⅢis stronger,and the duration of TypeⅡis longer.Because of extremely strong rainfall intensity and longer duration,TypeⅠsevere rainfall frequently leads to extreme precipitation events.The banded echo occurs most frequently produced by TypeⅠand the lump echo is mainly produced by TypeⅡwith sparse distribution.The floccose echo is mainly produced by TypeⅢwith weaker intensity.The strong echo is mainly concentrated in the middle and low level with a low echo mass center and the vertical structure is consistent with the characteristics of tropical rainfall event.Among the 10 severe rainfall processes with the train effect,7 are produced by the back-propagation of the banded echo or short-banded echo,and the other three by large-scale floccose echo.The average duration and precipitation of the 10 processes are twice of the average of the other processes.
作者
高帆
尹承美
蔡哲
焦洋
褚颖佳
李瑞
马蕾
GAO Fan;YIN Chengmei;CAI Zhe;JIAO Yang;CHU Yingjia;LI Rui;MA Lei(Jinan Meteorological Bureau,Jinan 250102,China)
出处
《海洋气象学报》
2019年第1期131-141,共11页
Journal of Marine Meteorology
基金
山东省气象局重点科研项目(2016sdqxz01
2016sdqxz05)
山东省气象局科研项目(sdjn2016-04)
中国气象局预报员专项(CMAYBY2019-063)
关键词
短时强降水
流型配置
降水特征
环境参数
回波特征
short-time severe rainfall
flow pattern configuration
precipitation characteristics
environmental parameters
echo characteristics
