Abstract View
Effect of Particle Properties to the Atmospheric Visibility
WEN-BIN LEE, Yeou-Lih Yan, Hsin-Chih Lai, Shao-Hao Lu, Ming-Tung Chuang, Tang-Huang Lin, Chea-Yuan Yang, Ying-I Tsai, Chih-Chieh Chen, Wen-Yinn Lin, National Taipei University of Technology
Abstract Number: 10
Working Group: Aerosol Chemistry
Abstract
Visibility degradation is a significant index impact of particle concentrations in atmospheric air. Scattering and absorption of visible light through suspended particles can be attributed to visibility degradation. However, different particle components may exhibit contrasting effect of extinction efficiency. This study aimed to determine the correlation between visibility and physical–chemical composition of particulate matter (PM)2.5. Four season samplings from November 2017 to July 2018 were obtained in Cianjin (urban) and Ciaotou (suburban) areas, Southern Taiwan. Aerosol optical properties were measured in terms of particle concentration, size distribution, and chemical compositions (e.g., NH4NO3, (NH4)2SO4, element carbon, and TOC) using an integrating nephelometer and an AE33 aethalometer. The variation in relative humidity may not directly influence the extinction coefficient of particles. Visibility reduction is mainly influenced by the increase in particle concentration. The particle extinction coefficient is correlated with the proportion of components. The concentration of particle compositions, such as (NH4)2SO4 and NH4NO3, in Cianjin is higher than that in Ciaotou. The size distribution in the visible region ranges from 0.4 µm to 0.7 µm. Therefore, the visibility in Cianjin is lower than that in Ciaotou. Visibility-related monitoring planning and strategy setting can be used to improve visual air quality by determining the correlation between PM2.5 properties and visibility.