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Frontiers of Environmental Science & Engineering

ISSN 2095-2201

ISSN 2095-221X(Online)

CN 10-1013/X

Postal Subscription Code 80-973

2018 Impact Factor: 3.883

Front. Environ. Sci. Eng.    2022, Vol. 16 Issue (5) : 65    https://doi.org/10.1007/s11783-022-1544-5
SHORT COMMUNICATION
Is atmospheric oxidation capacity better in indicating tropospheric O3 formation?
Peng Wang1,2, Shengqiang Zhu3, Mihalis Vrekoussis4,5, Guy P. Brasseur6,7, Shuxiao Wang8,9(), Hongliang Zhang2,3,10()
1. Department of Atmospheric and Oceanic Sciences, Fudan University, Shanghai 200438, China
2. IRDR ICoE on Risk Interconnectivity and Governance on Weather/Climate Extremes Impact and Public Health, Fudan University, Shanghai 200438, China
3. Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, China
4. Institute of Environmental Physics, University of Bremen, Bremen D-28359, Germany
5. Climate and Atmosphere Research Center (CARE-C), the Cyprus Institute, Nicosia 27456, Cyprus
6. Max Planck Institute for Meteorology, Hamburg 20146, Germany
7. National Center for Atmospheric Research, Boulder, CO 80307, USA
8. State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
9. State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China
10. Institute of Eco-Chongming (IEC), Shanghai 202162, China
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Abstract

● This study summarizes and evaluates different approaches that indicate O3 formation.

● Isopleth and sensitivity methods are useful but have many prerequisites.

● AOC is a better indicator of photochemical reactions leading to O3 formation.

Tropospheric ozone (O3) concentration is increasing in China along with dramatic changes in precursor emissions and meteorological conditions, adversely affecting human health and ecosystems. O3 is formed from the complex nonlinear photochemical reactions from nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs). Although the mechanism of O3 formation is rather clear, describing and analyzing its changes and formation potential at fine spatial and temporal resolution is still a challenge today. In this study, we briefly summarized and evaluated different approaches that indicate O3 formation regimes. We identify that atmospheric oxidation capacity (AOC) is a better indicator of photochemical reactions leading to the formation of O3 and other secondary pollutants. Results show that AOC has a prominent positive relationship to O3 in the major city clusters in China, with a goodness of fit (R2) up to 0.6. This outcome provides a novel perspective in characterizing O3 formation and has significant implications for formulating control strategies of secondary pollutants.

Keywords O3      AOC      O3 formation regime     
Corresponding Author(s): Shuxiao Wang,Hongliang Zhang   
Issue Date: 29 May 2022
 Cite this article:   
Peng Wang,Shengqiang Zhu,Mihalis Vrekoussis, et al. Is atmospheric oxidation capacity better in indicating tropospheric O3 formation?[J]. Front. Environ. Sci. Eng., 2022, 16(5): 65.
 URL:  
https://academic.hep.com.cn/fese/EN/10.1007/s11783-022-1544-5
https://academic.hep.com.cn/fese/EN/Y2022/V16/I5/65
Fig.1  (a) The O3 formation mechanism (highlighted parts are the major oxidants) modified from Steinfeld (1998) and (b) a typical O3 isopleth.
Senarios Indicators VOC-limited NOx-limited Transition
During COVID-19 HCHO/NO2 0.13 0.70 0.17
O3/NOy 0.11 0.40 0.49
H2O2/NOy 0.42 0.15 0.43
VOCs reduced by 50% HCHO/NO2 0.19 0.65 0.16
O3/NOy 0.14 0.39 0.47
H2O2/NOy 0.42 0.15 0.43
NOx reduced by 50% HCHO/NO2 0.02 0.85 0.13
O3/NOy 0.03 0.51 0.46
H2O2/NOy 0.24 0.19 0.57
VOCs and NOx reduced by 50% HCHO/NO2 0.04 0.79 0.17
O3/NOy 0.03 0.52 0.45
H2O2/NOy 0.25 0.19 0.56
Tab.1  Ratios of grid cells falling in different O3 formation regimes (VOC-limited, NOx-limited, and transition regimes) suggested by three different indicators during COVID-19 lockdown (January and February 2020) under different precursors reductions cases. All results are calculated using Community Multi-scale Air Quality (CMAQ) model
NB NCP YRD PRD
O3
During COVID-19 O3 = 3.7*HOx+0.2, R2 = 0.47 O3 = 1.8*HOx+0.6, R2 = 0.40 O3 = 1.2*HOx+1.6,R2 = 0.27
During COVID-19 O3 = 2.1*HOx+0.9, R2 = 0.42 O3 = 2.7*HOx?4.0, R2 = 0.60 O3 = 2.7*HOx?7.2, R2 = 0.43
NOx reduced by 50% O3 = 1.5*HOx+0.7, R2 = 0.49 O3 = 2.2*HOx?6.4, R2 = 0.03 O3 = 2.0*HOx?9.2, R2 = 0.55
VOCs reduced by 50% O3 = 1.3*HOx+0.7, R2 = 0.14 O3 = 2.8*HOx?3.4,R2 = 0.39 O3 = 1.9*HOx?7.0,R2 = 0.05
VOCs and NOx reduced by 50% O3 = 1.2*HOx+0.6, R2 = 0.29 O3 = 2.8*HOx?6.5, R2 = 0.69 O3 = 2.3*HOx?8.9, R2 = 0.46
Tab.2  The correlation between HOx and non-background (NB) O3 and O3 in the major city clusters (NCP, YRD and PRD regions) in China during COVID-19 under different emission control conditions. The NB O3 is the sum of O3 from all emission sources (including both anthropogenic and biogenic sources). Units for NB O3/O3 and HOx are ppb and ppt. Total grid cells are 284, 277, and 158 in the NCP, YRD, and PRD, respectively. Total data points are 10508, 10247, and 5846 in the NCP, YRD, and PRD, respectively
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