| Title: | Potential Factors Contributing to Ozone Production in AQUAS-Kyoto Campaign in Summer 2020: Natural Source-Related Missing OH Reactivity and Heterogeneous HO(2)/RO(2) Loss |
| Author(s): | Li J; Kohno N; Sakamoto Y; Pham HG; Murano K; Sato K; Nakayama T; Kajii Y; |
| Address: | "Graduate School of Global Environmental Studies, Kyoto University, Kyoto 606-8501, Japan. Regional Environment Conservation Division, National Institute for Environmental Studies, Ibaraki 305-8506, Japan. Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8316, Japan. Faculty of Environmental Science and Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "This study presents total OH reactivity, ancillary trace species, HO(2) reactivity, and complex isoprene-derived RO(2) reactivity due to ambient aerosols measured during the air quality study (AQUAS)-Kyoto campaign in September, 2020. Observations were conducted during the coronavirus disease (COVID-19) pandemic (associated with reduced anthropogenic emissions). The spatial distribution of missing OH reactivity highlights that the origin of volatile organic compounds (VOCs) may be from natural-emission areas. For the first time, the real-time loss rates of HO(2) and RO(2) onto ambient aerosols were measured continuously and alternately. Ozone production sensitivity was investigated considering unknown trace species and heterogeneous loss effects of XO(2) ( identical withHO(2) + RO(2)) radicals. Missing OH reactivity enhanced the ozone production potential by a factor of 2.5 on average. Heterogeneous loss of radicals could markedly suppress ozone production under low NO/NO(x) conditions with slow gas-phase reactions of radicals and change the ozone regime from VOC- to NO(x)-sensitive conditions. This study quantifies the relationship of missing OH reactivity and aerosol uptake of radicals with ozone production in Kyoto, a low-emission suburban area. The result has implications for future NO(x)-reduction policies. Further studies may benefit from the combination of chemical transport models and inverse modeling over a wide spatiotemporal range" |
| Keywords: | *Air Pollutants/analysis *Air Pollution *covid-19 Environmental Monitoring Humans *Ozone/chemistry Respiratory Aerosols and Droplets *Volatile Organic Compounds aerosol uptake field observation ozone production sensitivity radical reactivity; |
| Notes: | "MedlineLi, Jiaru Kohno, Nanase Sakamoto, Yosuke Pham, Huy Gia Murano, Kentaro Sato, Kei Nakayama, Tomoki Kajii, Yoshizumi eng 2022/09/08 Environ Sci Technol. 2022 Sep 20; 56(18):12926-12936. doi: 10.1021/acs.est.2c03628. Epub 2022 Sep 7" |
