https://scholars.lib.ntu.edu.tw/handle/123456789/597996
標題: | Quantifying the impacts of PM2.5 constituents and relative humidity on visibility impairment in a suburban area of eastern Asia using long-term in-situ measurements | 作者: | YU-CHIEH TING Young, Li-Hao Lin, Tang-Huang Tsay, Si-Chee Chang, Kuo-En TA-CHIH HSIAO |
關鍵字: | Hygroscopic aerosols;In-situ measurements;Light extinction;Mitigation strategies;Relative humidity;Visibility;Aerosols;Air quality;Atmospheric chemistry;Atmospheric humidity;Chemical analysis;Deterioration;Nitrogen compounds;Sulfur compounds;Aerosol extinction;Air pollutants;Chemical compositions;Environmental problems;Hygroscopic aerosol;In-situ measurement;Mitigation strategy;PM 2.5;Suburban areas;Visibility impairment | 公開日期: | 2021 | 來源出版物: | Science of the Total Environment | 摘要: | The deterioration of visibility due to air pollutants and relative humidity has been a serious environmental problem in eastern Asia. In most previous studies, chemical compositions of atmospheric particles were provided using filter-based offline analyses, which were unable to provide long-term and in-situ measurements that resolve sufficient temporal variations of air pollution and meteorology, hindering the resolution of the relationship between air quality and visibility. Here, we present a year-long continuously measured data from a comprehensive suite of online instruments to investigate diurnal and seasonal impacts of the aerosol chemical compositions in PM2.5 on visibility seasonally and diurnally. The measured dry aerosol extinction at λ = 550 nm reached a closure with that predicted by aerosol compositions within 12%. However, the hygroscopic growth of particles under ambient RH could enhance the aerosol extinction by a factor of 2–6, matching the perceptive visibility of the public. Particulate ammonium nitrate was most sensitive to reducing visibility, while ammonium sulfate contributed the most to the light extinction. In spring and winter, the monsoon and stagnant air masses reduced the visibility and increased PM2.5 (>35 μg m?3). The moisture was found to substantially enhance the light extinction under RH = 60–90%, reducing visibility by approximately 15 km, largely attributed to hygroscopic inorganic salts. This study serves as a metric to highlight the need to consider the influence of RH, and aqueous reactions in producing secondary inorganic aerosols on atmospheric visibility, underpinning the more accurate mitigation strategies of air pollution. ? 2021 Elsevier B.V. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120429081&doi=10.1016%2fj.scitotenv.2021.151759&partnerID=40&md5=18e3f276f834ccb55b62c215aa577f2f https://scholars.lib.ntu.edu.tw/handle/123456789/597996 |
ISSN: | 00489697 | DOI: | 10.1016/j.scitotenv.2021.151759 |
顯示於: | 環境工程學研究所 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。