摘要
利用自动站观测数据和ERA5再分析资料,对2009—2018年广东雷暴大风的时空分布及物理量变化特征进行分析。结果表明:雷暴大风多发于珠江三角洲北部至粤西北一带;自上午至傍晚雷暴大风高发区从南部沿海逐步北移至粤北一带。广东雷暴大风月分布呈双峰结构,分别在5和8月达到峰值;日变化特征明显,绝大部分集中在14:00—19:00,峰值出现在17:00。雷暴大风发生前12 h存在能量积累的过程。午后型雷暴大风不稳定能量条件更充足,更低层的初始扰动触发更有利。中层正涡度配合的上升运动特征在大风发生前3 h具有明显加强的趋势。午后型雷暴大风与自身低层高湿的水汽条件关联明显。前汛期其他时段雷暴大风动力驱动更明显;后汛期午后型雷暴大风热力驱动更明显。
Using the observations from automatic weather stations and ERA5 reanalysis,this work ana-lyzes the spatiotemporal distributions of thunderstorms that happened in Guangdong province from 2009 to 2018 and the variation characteristics of their physical quantities.The results are shown as follows.It is most likely for thunderstorms to take place in the northern part of Pearl River Delta and northwestern part of the province.From the morning to the time towards the evening,the most frequent zones of thunderstorms gradu-ally move northward from the coast of South China Sea to northern Guangdong.Their monthly distribution is bimodal,peaking in May and August respectively.Their diurnal variation is significant,concentrating in the period from 14:00 to 19:00,with the peak at 17:00.Energy accumulates within the 12 hours prior to the thunderstorm.The condition of instability energy is more sufficient and the triggering mechanism of lower-level initial disturbance is more efficient when thunderstorms happen after midday.Three hours before the thunderstorm,ascending motion accompanied by positive mid-level vorticity tends to intensify greatly.Thun-derstorms happening after midday are well correlated with the water vapor condition of moist low levels of their own.While the thunderstorm happening in periods other than the post-midday hours is driven much dy-namically in the April-June raining season,it is driven,when taking place after midday,much thermally in the July-September raining season.
作者
罗欣
张华龙
陈元昭
郑群峰
徐婷
张超
LUO Xin;ZHANG Hua-long;CHEN Yuan-zhao;ZHENG Qun-feng;XU Ting;ZHANG Chao(Meteorological Bureau of Shenzhen,Shenzhen 518040;National Climate Observatory of Shenzhen,Shenzhen 518040;Meteorological Observatory of Guangdong Province,Guangzhou 510640;Shenzhen Key Laboratory for Severe Weather in Southern China,Shenzhen 518040;Shenzhen Early Warning Release Center,Shenzhen 518040)
出处
《广东气象》
2023年第3期13-17,共5页
Guangdong Meteorology
关键词
天气学
雷暴大风
强对流
对流有效位能
环境参量
广东
synoptics
thunderstorm
severe convection
convective available potential energy
envi-ronmental parameter
Guangdong
