摘要
采用探空数据及地面常规观测资料,针对2008~2017年前汛期(4~6月)发生在华南地区的54次典型暖区暴雨过程的不稳定条件、水汽、能量和动力等环境场特征开展统计分析,并对普通暖区暴雨、特强暖区暴雨的参量条件进行了对比,基于百分位法提取了用以区分普通、特强暖区暴雨过程的关键阈值。结果表明:1)在众多常用的物理参量指标中,表征水汽条件的850 hPa温度露点差、大气可降水量以及表征动力条件的深层垂直风切变对典型华南暖区暴雨事件的发生具有较清晰指示意义。华南暖区暴雨发生前大气可降水量充沛且对流层低层水汽接近饱和,结合一定的抬升条件,大气能迅速发生凝结潜热释放,并在深层垂直风切变的作用下组织化发展,从而使对流持续形成暴雨。当大气环境满足850 hPa的温度露点差≤2.2℃、大气可降水量≥56 mm、深层垂直风切变≥9 m/s时,有利于暖区暴雨的发生。2)相较于普通暖区暴雨事件,特强暖区暴雨事件在大气层结上具有更为充沛的对流层低层水汽条件,当大气环境满足850 hPa的温度露点差≤2.0℃时,特强暖区暴雨发生的概率更高。
The environment features under unstable conditions,water vapor,energy and dynamics conditions were studied by using sounding data and conventional observation data for 54 warm-sector heavy rainfall cases in South China from April to June during 2008-2017.The thresholds of key environmental parameters to distinguish the significantly strong warm-sector heavy rainfall cases are extracted with percentile method.The conclusions are shown as follows:(1)The depression of dew point at 850 hPa,the atmospheric precipitation and the deep vertical wind shear can be used to predict the occurrence of warm-sector heavy rainfall in South China.The water vapor in the lower troposphere is nearly saturated with high atmospheric precipitation before the occurrence of warm-sector heavy rainfall.Combined with certain lifting conditions,the latent heat can be released from water vapor condensation in the atmosphere,so that the convection can continue to form rainstorm.The thresholds of physical parameters include depression of dew point≤2.2℃at 850 hPa,atmospheric precipitation≥56 mm and deep vertical wind shear≥9 m/s.The above conditions are favorable for the generation of warm-sector heavy rainfall.(2)Compared with common warm-sector heavy rainfall,the significantly strong warm-sector heavy rainfall is of more sufficient water vapor in the lower troposphere.Under the condition of depression of dew point≤2.0℃at 850 hPa,the probability of significantly strong warm-sector heavy rainfall is higher.
作者
万轶婧
王东海
梁钊明
曾智琳
WAN Yijing;WANG Donghai;LIANG Zhaoming;ZENG Zhilin(School of Atmospheric Sciences,Sun Yat-sen University,Zhuhai 519082,China;Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies,Zhuhai 519082,China;Southern Laboratory of Ocean Science and Engineering(Guangdong,Zhuhai),Zhuhai 519082,China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China)
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第6期51-63,共13页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家自然科学基金(41775097,41861164027)
广东省科技计划项目(20170244)
广东省科技计划项目(2017 B020218003)
海南省南海气象防灾减灾重点实验室开放基金(SCSF201801)。
关键词
华南暖区暴雨
探空资料
物理参量
环境条件
warm-sector heavy rainfall in South China
sounding data
physical parameter
environment conditions
