Progress in quantitative research on the relationship between atmospheric oxidation and air quality

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Air Pollution Control

Background:

• Atmospheric oxidizing capacity (AOC) is crucial for tropospheric chemistry and self-cleaning, but its definition and quantification are uncertain.
• Recent national demands for air pollution control in China have spurred significant progress in AOC research by Chinese scholars.

Purpose of the Study:

• To review recent developments in atmospheric chemistry research concerning AOC in China.
• To present novel AOC indexes and their application in understanding and controlling air pollution.

Main Methods:

• Established apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) indexes based on macrothermodynamics and microdynamics.
• Utilized closed studies and domestic instruments for quantitative contributions of heterogeneous chemistry and radical detection.
• Employed laboratory smoke chamber simulations and the GRAPES-CUACE adjoint model for oxidant reaction analysis and air pollution modeling.

Main Results:

• Refined quantitative contributions of heterogeneous chemistry to AOC in Beijing and applied methods nationwide.
• Enabled detection of key atmospheric radicals (OH·, HO₂·, NO₃·) and reservoir molecules using domestic instruments.
• Optimized simulations of atmospheric oxidation, secondary aerosol formation, and regional AOC coordination, informing O₃ and PM_2.5 control strategies.

Conclusions:

• Significant advancements have been made in AOC research in China, providing robust tools for air pollution assessment and control.
• The developed AOC indexes and modeling approaches offer a foundation for effective regional air quality management, particularly for O₃ and PM_2.5.