Observational Study and Parameterization of Aerosol-fog Interactions

Monday, 15 December 2014
Jing Duan1,2, Xueliang Guo1, Yangang Liu2, Chungang Fang1, Zhengjun Su1 and Yong Chen3, (1)CAMS Chinese Academy of Meteorological Sciences, Beijing, China, (2)Brookhaven Natl Lab, Upton, NY, United States, (3)Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
Studies have shown that human activities such as increased aerosols affect fog occurrence and properties significantly, and accurate numerical fog forecasting depends on, to a large extent, parameterization of fog microphysics and aerosol-fog interactions. Furthermore, fogs can be considered as clouds near the ground, and enjoy an advantage of permitting comprehensive long-term in-situ measurements that clouds do not. Knowledge learned from studying aerosol-fog interactions will provide useful insights into aerosol-cloud interactions. To serve the twofold objectives of understanding and improving parameterizations of aerosol-fog interactions and aerosol-cloud interactions, this study examines the data collected from fogs, with a focus but not limited to the data collected in Beijing, China. Data examined include aerosol particle size distributions measured by a Passive Cavity Aerosol Spectrometer Probe (PCASP-100X), fog droplet size distributions measured by a Fog Monitor (FM-120), Cloud Condensation Nuclei (CCN), liquid water path measured by radiometers and visibility sensors, along with meteorological variables measured by a Tethered Balloon Sounding System (XLS-Ⅱ) and Automatic Weather Station (AWS). The results will be compared with low-level clouds for similarities and differences between fogs and clouds.