Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5753471 | Atmospheric Environment | 2017 | 13 Pages |
Abstract
The Lulin Atmospheric Background Station (LABS, 23.47°N 120.87°E, 2862 m ASL) in Central Taiwan was constructed in 2006 and is the only high-altitude background station in the western Pacific region for studying the influence of continental outflow. In this study, extensive optical properties of aerosols, including the aerosol light scattering coefficient (Ïs) and light absorption coefficient (Ïa), were collected from 2013 to 2014. The intensive optical properties, including mass scattering efficiency (αs), mass absorption efficiency (αa), single scattering albedo (Ï), scattering Ã
ngstrÓ§m exponent (Ã
), and backscattering fraction (b), were determined and investigated, and the distinct seasonal cycle was observed. The value of αs began to increase in January and reached a maximum in April; the mean in spring was 5.89 m2 gâ1 with a standard deviation (SD) of 4.54 m2 gâ1 and a 4.48 m2 gâ1 interquartile range (IQR: 2.95-7.43 m2 gâ1). The trend was similar in αa, with a maximum in March and a monthly mean of 0.84 m2 gâ1. The peak values of Ï (Mean = 0.92, SD = 0.03, IQR: 0.90-0.93) and Ã
(Mean = 2.22, SD = 0.61, IQR: 2.12-2.47) occurred in autumn. These annual patterns of optical properties were associated with different long-range transport patterns of air pollutants such as biomass burning (BB) aerosol in spring and potential anthropogenic emissions in autumn. The optical measurements performed at LABS during spring in 2013 were compared with those simultaneously performed at the Doi Ang Kang Meteorology Station, Chiang Mai Province, Thailand (DAK, 19.93°N, 99.05°E, 1536 m a.s.l.), which is located in the Southeast Asia BB source region. Furthermore, the relationships among αs, αa, and b were used to characterize the potential aerosol types transported to LABS during different seasons, and the data were inspected according to the HYSPLIT 5-day backward trajectories, which differentiate between different regions of air mass origin.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Ta-Chih Hsiao, Wei-Nai Chen, Wei-Cheng Ye, Neng-Huei Lin, Si-Chee Tsay, Tang-Huang Lin, Chung-Te Lee, Ming-Tung Chuang, Peter Pantina, Sheng-Hsiang Wang,