AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Correlation between Atmospheric Visibility and the Physical Properties and Chemical Compositions of Aerosol
CHISUNG LIANG, Sheng-Kai Jan, Jin-Yuan Syu, Wen-Yinn Lin, Institute of Environmental Engineering and Management
Abstract Number: 176 Working Group: Urban Aerosols
Abstract This study investigates the correlation between atmospheric visibility and the chemical composition and physical properties (number concentration, surface area concentration, and volume concentration) of aerosols. In order to understand how urban and suburban aerosol influence visibility, we collected the data from Taipei City and Yunlin County during four seasons. Ambient aerosol were sampled and analyzed for 12 constituents: water-soluble ionic species (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO3- , S042-) and carbonaceous contents (OC, EC, and TC). The result showed that the number concentration of particles increased significantly in the evening and morning when compared with other times, probably due to the effect of mobile sources in rush hours. Comparing the number concentration, surface area concentration, volume concentration with regards to their influence on visibility, the study finds that surface area concentration is most strongly correlated with visibility. The composition of ion and carbon affected the size of particles and so did the relative humidity. When relative humidity reached 70%, the atmospheric water affected the suspended size of particles. During the winter, the particle size and concentration of the water-soluble ionic species were smaller than in the fall. The results will be discussed in detail in this paper.