Literature Seminar
Ozone is a key air pollutant that impacts human and ecosystem health, and acts as a short-lived climate forcer. Despite being the focus of many decades or research, atmospheric ozone trends in urban areas can still be difficult to predict. Based on previous laboratory and modeling studies,1,2 heterogeneous uptake of atmospheric HO2 on to particles is a potential mechanism for enhancing ozone pollution in the face of reduced anthropogenic emissions. However, due to the analytical challenges in measuring ambient uptake coefficients, a detailed understanding of aerosol influences on ozone is not currently available and relies on alternative methods, including budget analyses and air pollution trend analysis. A recent study from Tan et al. (2020),3 utilizing budget analysis of HO2 and other ozone precursors in Wangdu, China found that reactive uptake on aerosols was not an important ozone limiting factor. This model-measurement discrepancy reinforces the need for a more comprehensive understanding of the relationships between ozone and particulate matter. The recent and drastic reductions in emissions and overall pollution during COVID-19 related lockdown periods could serve as an opportunity to evaluate the global relationship between particulate matter and ozone.
References
[1] Taketani, F.; Kanaya, Y.; Pochanart, P.; Liu, Y.; Li, J.; Okuzawa, K.; Kawamura, K.; Wang, Z.; Akimoto, H. Measurement of overall uptake coefficients for HO2 radicals by aerosol particles sampled from ambient air at Mts. Tai and Mang (China). Atmos. Chem. Phys. 2012, 12, 11907-11916. [2] Li, K.; Jacob, D. J.; Liao, H.; Shen, Lu.; Zhang, Q.; Bates, K. H. Anthropogenic drivers of 2013-2017 trends in summer surface ozone in China. PNAS 2019, 116, 422-427. [3] Tan, Z.; Hofzumahaus, A.; Lu, K.; Brown, S. S.; Holland, F.; Huey, G. L.; Kiendler-Scharr, A.; Li, X.; Liu, X.; Ma, N.; Min, K.-E.; Rohrer, F.; Shao, M.; Wahner, A.; Wang, Y.; Wiedensohler, A.; Wu, Y.; Wu, Z.; Zeng, L.; Zhang, Y.; Fuchs, H. No evidence for a significant impact of heterogeneous chemistry on radical concentrations in the North China Plain in Summer 2014. Environ. Sci. Tech. 2020, 54, 5973-5979.
