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© 2018. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

The impacts of black carbon (BC) aerosols on air quality, boundary layer dynamics and climate depend not only on the BC mass concentration but also on the light absorption capability of BC. It is well known that the light absorption capability of BC depends on the amount of coating materials (namely other species that condense and coagulate on BC). However, the difference of light absorption capability of ambient BC-containing particles under different air pollution conditions (e.g., clean and polluted conditions) remains unclear due to the complex aging process of BC in the atmosphere. In this work, we investigated the evolution of light absorption capability for BC-containing particles with changing pollution levels in urban Beijing, China. During the campaign period (17 to 30 November 2014), with an increase in PM1 concentration from 10 to 230 µgm-3, we found that the mass-weighted averages of the aging degree and theoretical light absorption capability of BC-containing particles increased by 33 % and 18 %, respectively, indicating stronger light absorption capability of BC-containing particles under more polluted conditions due to more coating materials on the BC surface. By using an effective emission intensity (EEI) model, we further found that aging during regional transport plays an important role in the difference in the light absorption capability of BC-containing particles under different air pollution levels. During the pollution episode, 63 % of the BC over Beijing originated from regional sources outside of Beijing. These regionally sourced BC-containing particles were characterized by more coating materials on BC surfaces due to more coating precursors within more polluted air, which contributed 75 % of the increase in theoretical light absorption capability of BC observed in Beijing during the polluted period (PM1 of 230 µgm-3) compared to that in the clean period (PM1 of 10 µgm-3). Due to the increase in theoretical light absorption capability of BC associated with air pollution, the direct radiative forcing of BC was estimated to be increased by 18 % based on a simple radiation transfer model. Our work identified an amplification of theoretical light absorption and direct radiative forcing under a more polluted air environment due to more coating materials on BC. The air pollution control measures may, however, break the amplification effect by reducing emissions of both BC and the coating precursors and achieve co-benefits of both air quality and climate.

Details

Title
Amplification of light absorption of black carbon associated with air pollution
Author
Zhang, Yuxuan 1 ; Zhang, Qiang 2 ; Cheng, Yafang 3   VIAFID ORCID Logo  ; Su, Hang 3   VIAFID ORCID Logo  ; Li, Haiyan 4   VIAFID ORCID Logo  ; Li, Meng 1   VIAFID ORCID Logo  ; Zhang, Xin 2 ; Ding, Aijun 5   VIAFID ORCID Logo  ; He, Kebin 4 

 Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China; Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany 
 Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China 
 Institute for Environmental and Climate Research, Jinan University, Guangzhou 510630, China; Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany 
 State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China 
 Institute for Climate and Global Change Research, School of Atmospheric Sciences, Nanjing University, Nanjing, China 
Pages
9879-9896
Publication year
2018
Publication date
2018
Publisher
Copernicus GmbH
ISSN
16807316
e-ISSN
16807324
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2068734660
Copyright
© 2018. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.