Preprints
https://doi.org/10.5194/acp-2021-850
https://doi.org/10.5194/acp-2021-850

  08 Nov 2021

08 Nov 2021

Review status: this preprint is currently under review for the journal ACP.

The impact of chlorine chemistry combined with heterogeneous N2O5 reactions on air quality in China

Xiajie Yang1,2, Qiaoqiao Wang1,2, Nan Ma1,2, Weiwei Hu3, Yang Gao4, Zhijiong Huang1,2, Junyu Zheng1,2, Bin Yuan1,2, Ning Yang1,2, Jiangchuan Tao1,2, Juan Hong1,2, Yafang Cheng5, and Hang Su5 Xiajie Yang et al.
  • 1Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
  • 2Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 511443, China
  • 3Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
  • 4Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China
  • 5Max Planck Institute for Chemistry, Mainz 55128, Germany

Abstract. The heterogeneous reaction of N2O5 on Cl-containing aerosols (N2O5 − ClNO2 chemistry) plays a key role in chlorine activation, NOx recycling and consequently O3 formation. In this study, we use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 − ClNO2 chemistry (i.e. the uptake coefficient of N2O5N2O5) and the ClNO2 yield (φClNO2)) to investigate the impacts of chlorine chemistry on air quality in China, the role of N2O5 − ClNO2 chemistry, as well as their sensitivities to chlorine emissions and parameterizations for γN2O5 and φClNO2. The model evaluation with multiple data sets observed across China demonstrated significant improvement especially regarding the simulation of Cl, N2O5 and ClNO2 with the updates in chlorine emissions and N2O5 − ClNO2 chemistry. Total tropospheric chlorine chemistry could increase annual mean MDA8 O3 by up to 4.5 ppbv but decrease PM2.5 by up to 7.9 μg m−3 in China, 83 % and 90 % of which could be attributed to the effect of N2O5 – ClNO2 chemistry. The heterogeneous uptake of N2O5 on chloride-containing aerosol surfaces is an important loss pathway of N2O5 as well as a important source of O3, and hence is particularly useful in elucidating the commonly seen ozone underestimations. The importance of chlorine chemistry largely depends on both chlorine emissions and the parameterizations for N2O5 – ClNO2 chemistry. With the additional chlorine emissions annual mean maximum daily 8-hour average (MDA8) O3 in China could be increased by up to 3.5 ppbv. The corresponding effect on PM2.5 concentrations varies largely with regions, with an increase of up to 4.5 μg m−3 in the North China Plain but a decrease of up to 3.7 μg m−3 in the Sichuan Basin. On the other hand, even with the same chlorine emissions, the effects on MDA8 O3 and PM2.5 in China could differ by 48 % and 27 %, respectively between different parameterizations.

Xiajie Yang et al.

Status: open (until 20 Dec 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Xiajie Yang et al.

Xiajie Yang et al.

Viewed

Total article views: 401 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
305 89 7 401 20 1 6
  • HTML: 305
  • PDF: 89
  • XML: 7
  • Total: 401
  • Supplement: 20
  • BibTeX: 1
  • EndNote: 6
Views and downloads (calculated since 08 Nov 2021)
Cumulative views and downloads (calculated since 08 Nov 2021)

Viewed (geographical distribution)

Total article views: 281 (including HTML, PDF, and XML) Thereof 281 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 01 Dec 2021
Download
Short summary
We use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 − ClNO2 chemistry to investigate the impacts of chlorine chemistry on air quality in China. Our study not only significantly improves the model’s performance, but also demonstrates the importance of non-sea salt chlorine sources as well as an appropriate parameterization for N2O5−ClNO2 chemistry to the impact of chlorine chemistry in the atmosphere.
Altmetrics