An examination of the physical and optical properties of aerosols collected in the IMPROVE program |
| |
| Institution: | 1. Department of Environment and Energy Engineering, Chonnam National University, 77 Yongbong-ro, Gwangju 61186, Republic of Korea;2. Center for Gas Analysis, Korea Research Institute of Standards and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea;1. Department of Civil and Environmental Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, HungHom, Kowloon, Hong Kong;2. College of Environment and Energy, South China University of Technology, Higher Education Mega Centre, Guangzhou 510006, China;3. Department of Environmental Science and Technology, School of Human Settlements and Civil Engineering, Xi''an Jiaotong University, No. 28 Xianning West Road, Xi''an, Shaanxi, 710049, China;4. Key Lab of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi''an, 710075, China |
| |
| Abstract: | The Interagency Monitoring of Protected Visual Environments (IMPROVE) protocols for reconstructing the ambient light extinction coefficient (bext) from measured aerosol species are the basis for evaluating compliance under the Regional Haze Rule. Aerosol mass composition and optical properties have been measured as part of the IMPROVE program since 1988, providing a long-term data set of aerosol properties at 38 sites around the US. This data set is used to evaluate assumptions made in calculating reconstructed mass and bext by applying statistical analysis techniques. In particular, the molecular weight to carbon weight ratio used to compute particulate organic matter is investigated. An annual average value of 1.7±0.2 for the IMPROVE sites, compared to the value of 1.4 currently assumed in the IMPROVE algorithm, is derived. Regression analysis also indicates that fine soil mass concentrations are underestimated by roughly 20% on average. Finally, aerosol mass scattering and extinction efficiencies assumed in the IMPROVE reconstructed bext protocol are examined. Fine mode (Dp<2.5 μm) mass scattering efficiencies have a functional dependence on mass concentrations at many sites, and use of a mass-concentration-dependent adjustment factor to refine the assumed efficiencies provides for closer agreement between measured and reconstructed bext. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
