摘要
基于2018年8月31日山西太原地区的一次暖云观测资料,对云滴数浓度(N c)和云滴谱离散度(ε)垂直分布特征进行了分析。结果表明:N c和ε随高度变化复杂,云中垂直速度、逆温区和夹卷均为影响ε和N c垂直分布的重要因子。上升气流(或下沉气流)随高度增加而增强(减弱)时,ε和N c均随高度增加而增大,且两者呈正相关。云中存在上升速度或下沉速度极大值时,上升气流易产生碰并增长,N c随高度增加而减小,与ε呈负相关,而下沉气流则促进气溶胶再活化使得云滴增多,与ε呈负相关。云中逆温区厚度和强度影响逆温区及其上部云区的ε垂直分布及N c和ε间的相关性,逆温层较厚时,ε随高度增加而减小,N c与ε呈正相关。逆温层较薄时,ε随高度的增加而增大,N c和ε呈负相关。逆温区上部云中未饱和,云滴蒸发,N c和ε分别随高度增加而减小,N c和ε呈正相关。云顶附近夹卷作用使N c随高度增加而减小,N c与ε呈正相关。
Based on an aircraft observation of a warm cloud in Taiyuan,Shanxi province on August 31,2018,we analyzed the vertical distribution and causes of the number concentration(N c)and spectral dispersion(ε)of cloud droplet.The results show that N c andεvary complexly with altitude,and their vertical distributions are mainly affected by vertical velocity,inversion zone,and clamp coil in clouds.When the upwelling(or downwelling)increases(weakens)with height,bothεand N c increase,and show a positive correlation with each other.When there is a maximum of upwelling or downwelling,the upwelling is easy to produce collision coalescence growth,and N c decreases with the increase of height and has a negative correlation withε.However,the downwelling promotes aerosol reactivation and then makes cloud droplets increase and has a negative correlation withε.The thickness and intensity of the inversion zone affect the vertical distribution ofεand the correlation between N c andεin the inversion zone and its upper cloud area.When the inversion layer is thicker,εdecreases with the increase in height,and N c andεare positively related.Inversely,when the inversion layer is thin,εincreases with the increase of height,and N c andεare negatively related.The upper cloud in the inversion area is not saturated,and the cloud droplet is evaporated,both N c andεdecrease with increasing height and are positively correlated.The entrainment near the cloud top makes N c decrease with the increase in height,and there is a positive correlation between N c andε.
作者
伊智铭
杨素英
李义宇
康娜
余国行
李娅茹
张严哲
YI Zhi-ming;YANG Su-ying;LI Yi-yu;KANG Na;YU Guo-hang;LI Ya-ru;ZHANG Yan-zhe(Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,School of Atmospheric Physics,Nanjing University of Information Science and Technology,Nanjing 210044,China;Weather Modification Office,Meteorological Disasters Defense Technology Center,Meteorological Service of Shanxi Province,Taiyuan 030032,China)
出处
《气象与环境学报》
2022年第6期48-56,共9页
Journal of Meteorology and Environment
基金
科技部重点研发计划项目((2017YFC1501404))
国家自然科学基金项目(41575133)
省级大学生创新创业训练计划(202110300003Z)共同资助。
关键词
离散度
垂直速度
夹卷
逆温区
Dispersion
Vertical velocity
Entrainment
Inversion zone
