Sensitivities of Ozone Air Pollution in the Beijing–Tianjin–Hebei Area to Local and Upwind Precursor Emissions Using Adjoint Modeling

Abstract

Effective mitigation of surface ozone pollution entails detailed knowledge of the contributing precursors' sources. We use the GEOS-Chem adjoint model to analyze the precursors contributing to surface ozone in the Beijing−Tianjin−Hebei area (BTH) of China on days of different ozone pollution severities in June 2019. We find that BTH ozone on heavily polluted days is sensitive to local emissions, as well as to precursors emitted from the provinces south of BTH (Shandong, Henan, and Jiangsu, collectively the SHJ area). Heavy ozone pollution in BTH can be mitigated effectively by reducing NO x (from industrial processes and transportation), ≥C 3 alkenes (from on-road gasoline vehicles and industrial processes), and xylenes (from paint use) emitted from both BTH and SHJ, as well as by reducing CO (from industrial processes, transportation, and power generation) and ≥C 4 alkanes (from industrial processes, paint and solvent use, and on-road gasoline vehicles) emissions from SHJ. In addition, reduction of NO x , xylene, and ≥C 3 alkene emissions within BTH would effectively decrease the number of BTH ozone-exceedance days. Our analysis pinpoint the key areas and activities for locally and regionally coordinated emission control efforts to improve surface ozone air quality in BTH.

Trends and Variability of Ozone Pollution over the Mountain-Basin Areas in Sichuan Province during 2013–2020: Synoptic Impacts and Formation Regimes

“…The MDA8 ozone formation in Chengdu is VOC-limited in less polluted days and transition regime in heavily polluted days. Similar results are presented by Wang et al [64] in the Beijing-Tianjin-Hebei region. The MDA8 ozone in Neijiang and Suining is NO x -limited.…”

Assessing the change of ambient air quality patterns in Jiangsu Province of China pre-to post-COVID-19

“… in the stratosphere protects the earth, but a high concentration of near the ground endangers human health. pollution is not as visible as PM 2.5 pollution; its harm to human health is mainly reflected by irritation and damage to the eyes and respiratory tract ( Betancourt-Odio,2021 ; Higham, 2021 ; Wang, 2021 ). near the ground originates from vertical transport in the stratosphere, while in the troposphere it is composed of precursors such as nitrogen oxides ( ), CO and VOCs.…”

Optimization of a NOx and VOC Cooperative Control Strategy Based on Clean Air Benefits

“…Another challenge comprises the optimization of NO x and VOC precursor emissions to effectively reduce PM 2.5 and O 3 concentrations, particularly for O 3 as it strongly depends on the relative changes of NO x and VOC in addition to the absolute changes . Some studies have emphasized the importance of VOC reduction in urban areas, which usually exhibit strong VOC sensitivity. − Additionally, another study determined that NO x reduction can also decrease the peak O 3 levels due to the NO x -sensitive regime during peak O 3 hours in the metropolitan region. , The short-term control strategy can be analyzed based on the current O 3 formation sensitivity in the region. However, to substantially reduce O 3 concentrations, the NO x emissions as well as, or instead of, VOCs need to be controlled, which was also verified by the O 3 pollution control in the United States.…”