摘要
课题组于2017年冬季在南京北郊开展了为期45d的雾/霾外场综合观测,并选取12月30～31日一次平流辐射雾过程,分析了气象要素、雾和气溶胶的宏微观特征.结果表明:冷平流与夜间辐射冷却造成的持续性降温为此次雾发展的主要原因,而短波辐射增强则为雾消散的主导因子;此次雾过程存在爆发性增长的特征,表现为17min内含水量的量级由10^(-4)g/m^3增加至10^(-1)g/m^3,其中雾滴数浓度的增加对其贡献率可达67%;强浓雾微物理量的时间变率波动性强,雾的水平分布存在显著的不均匀性特征;日出后的强浓雾阶段中存在纳米级气溶胶累积现象,空气动力学直径在10～50nm气溶胶的数浓度增加率可达2817cm^3/h,从二次气溶胶生成(SO_2的气-粒及气-液转化过程)、输送(人为活动造成的气溶胶累积及雾中垂直向湍流的输送)等方面探讨现象出现的原因.
A systematic field observation of the haze and fog was conducted and last 45 days in the northern suburbs of Nanjing during the winter of 2017.In this study,an advection radiation fog event from December 30 to 31 was forced on,and the meteorological elements,the macroscopic and microscopic features of fogs and aerosols were analyzed.It was found that the continuous cooling caused by cold advections and the long-wave night sky radiation dominated the development of fog,and the enhancement of short-wave radiation leaded to the fog dissipation.There was an explosive growth in the fog,where the liquid water content increased by three orders of magnitude from 10^-4g/m^3 to 10^-1g/m^3 within 17 minutes,and the increasing number concentration of fog droplets contributed 67%to the explosive growth.There was an obvious characteristic of uneven distribution in the strong fog.In addition,a new phenomenon of nano-scale aerosols accumulation in the strong fog was observed after sunrise,where the increment speed of the number concentration of the aerosols with diameters from 10nm to 50nm reached 2817cm^-3/h.The following parts were examined to discuss the reasons for the cumulative event,including the secondary aerosol generation,i.e.,gas-to-particle and gas-to-liquid conversions of SO2,and aerosols transport process,i.e.,the local aerosols accumulation from human activities and a potential turbulence transport mechanism in fogs.
作者
王元
牛生杰
吕晶晶
王静
胡春阳
WANG Yuan;NIU Sheng-jie;Lü Jing-jing;WANG Jing;HU Chun-yang(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Nanjing University of Information Science and Technology,Nanjing 210044,China;Nanjing Tech University,Nanjing 211816,China;Unit 94582 of PLA,Queshan,463217,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2019年第2期459-468,共10页
China Environmental Science
基金
国家重点研发计划(2018YFC150790X)
国家自然科学基金资助项目(41775134)
江苏省研究生科研创新计划资助项目(KYCX17-0884)
关键词
平流辐射雾
气象条件
微物理特征
纳米级气溶胶累积
advection radiation fog
meteorological elements
microphysical characteristics
cumulative eventof nano-scale aerosols
