OPEN ACCESS

Articles online

Implication of Light Absorption Enhancement and Mixing State of Black Carbon (BC) by Coatings in Hong Kong

Category: Aerosol and Atmospheric Chemistry

Accepted Manuscripts
DOI: 10.4209/aaqr.2017.11.0473
PDF | RIS | BibTeX

Guo-Liang Li1, Li Sun1, Kin-Fai Ho2, Ka-Chun Wong1, Zhi Ning 1,3

  • 1 School of Energy and Environment, City University of Hong Kong, Hong Kong, China
  • 2 The Jockey Club School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China
  • 3 Guy Carpenter Asia-Pacific Climate Impact Centre, City University of Hong Kong, Hong Kong, China

Highlights

Light absorption enhancement (Eabs) of BC by coatings was ~1.6.
Lensing effect was probably attributed to ammonium and sulfate.
The ratio of coating thickness to BC core radius was ~1.0–2.0.


Abstract

Simultaneous measurement of black carbon (BC) and non-refractory PM1 aerosol chemical compositions was performed in Autumn, 2016 at a suburban site of Hong Kong. A thermodenuder (TD) was employed at different heating temperatures to remove semi-volatile aerosol fractions to varying degree. Light absorption enhancement (Eabs) of BC by semi-volatile coatings at seven wavelengths was evaluated, and the coating fractions was further analyzed. Result showed overall Eabs was 1.58 ± 0.13 (470 nm)–1.64 ± 0.16 (660 nm) measured at 280°C, whereas Eabs increased very little from 50°C (1.02–1.04) to 200°C (1.13–1.20). The lensing-effect-related Eabs was probably attributed to the presence of ammonium and sulfate. Furthermore, the ratio of coating thickness to BC core radius was around 1.0–2.0 based on Mie calculation. This work evaluated the Eabs by coatings in Hong Kong and implied the BC mixing state, thus could provide critical reference for climate model on the role of aerosol in global warming.

Keywords

Thermodenuder BC coating Mie calculation


Related Article

Seasonal Source Apportionment of PM2.5 in Ningbo, a Coastal City in Southeast China

Mengren Li, Min Hu , Qingfeng Guo, Tianyi Tan, Bohan Du, Xiaofeng Huang, Lingyan He, Song Guo, Weifeng Wang, Yingguo Fan, Dandan Xu
Accepted Manuscripts
DOI: 10.4209/aaqr.2018.01.0011
PDF

Oxidative Capacity and Radical Chemistry in a Semi-arid and Petrochemical-industrialized City, Northwest China

Chenhui Jia, Yanan Wang, Yaojie Li, Tao Huang, Xiaoxuan Mao, Jingyue Mo, Jixiang Li, Wanyanhan Jiang, Xiaoxue Liang, Hong Gao, Jianmin Ma
;