摘要
利用2015—2021年4—9月中国气象局全国地闪定位网的地闪观测资料与MERRA2气溶胶光学厚度再分析资料,分析长江三角洲及其周边地区(27.5°~35°N,115°~122.5°E)地闪活动与不同种类气溶胶的关系。结果表明:不同种类气溶胶与地闪活动的关系不同,有地闪日的硫酸盐气溶胶光学厚度更高,无地闪日的沙尘气溶胶光学厚度更高,地闪多发生在硫酸盐气溶胶光学厚度较高且沙尘气溶胶光学厚度较低的环境中。当硫酸盐气溶胶光学厚度低于阈值时,在一定相对湿度条件下地闪密度与硫酸盐气溶胶光学厚度为正相关关系,当硫酸盐气溶胶光学厚度高于阈值时,地闪密度有减小的趋势或趋势不明显,且不同月份的阈值不同。因此,气溶胶的云微物理作用与辐射效应的叠加使得气溶胶与地闪活动的关系更为复杂,而沙尘气溶胶与地闪密度在4—6月呈负相关关系,7—9月相关不显著。
Lightning activity poses threats to human life and property safety.A large volume studies indicate that aerosol plays a significant role in lightning activity.To explore the effect of different types of aerosols on lightning activity in the Yangtze River Delta and its surrounding areas,cloud-to-ground(CG)lightning location data and aerosol optical depth from reanalysis dataset is analyzed in the target area(27.5°-35°N,115°-122.5°E)during 2015-2021.The spatial distribution of aerosol optical depth(AOD)with CG lightning condition and without CG lightning condition,and monthly variation of aerosol concentration under two conditions are investigated.All the grids in the target region show that sulfate AOD is higher,while dust AOD is lower with CG lightning.In summer there are little differences between the AOD with CG lightning and without CG lightning conditions.In other months,more sulfate aerosol and less dust aerosol are found with CG lightning condition.The spatial distribution of CG lightning density difference under higher and lower AOD conditions is given.The results show that when the sulfate AOD is high,the CG lightning density of most grids is higher.The CG lightning density is significantly lower when the dust AOD is high.The correlation coefficient between CG lightning density and the AOD for different types of aerosols is calculated for the months when CG lightning is active.When the concentration of sulfate aerosol is low,the correlation coefficient between sulfate AOD and CG lightning density is significant.When the sulfate aerosol concentration exceeds a certain threshold,there is no significant correlation between CG lightning density and sulfate AOD.The positive correlation may be due to the fact that the cloud microphysical effect of sulfate aerosols can promote the development of convection.With sufficient water vapors,sulfate aerosols form cloud condensation nuclei and promote CG lightning activity.When the concentration of sulfate aerosols is higher than the threshold value,the cloud microp
作者
吴啸天
王晓妍
郑栋
张义军
Wu Xiaotian;Wang Xiaoyan;Zheng Dong;Zhang Yijun(Department of Atmospheric and Oceanic Sciences,Fudan University,Shanghai 200438;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081)
出处
《应用气象学报》
CSCD
北大核心
2023年第5期608-618,共11页
Journal of Applied Meteorological Science
基金
国家自然科学基金项目(42175090)。
关键词
地闪活动
气溶胶
云微物理作用
cloud-to-ground lightning activity
aerosol
cloud microphysics
