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Future tropospheric ozone budget and distribution over East Asia under a Net Zero scenario.
- Source :
- EGUsphere; 7/21/2023, p1-26, 26p
- Publication Year :
- 2023
-
Abstract
- Under future net zero emission policies, reductions in emissions of ozone (O<subscript>3</subscript>) precursors are expected to alter the temporal and spatial distribution of tropospheric O<subscript>3</subscript>. In this study, we quantify changes in the tropospheric O<subscript>3</subscript> budget, spatiotemporal distribution of surface O<subscript>3</subscript> in East Asia and the contributions from regional emissions, intercontinental transport and climate change between the present day and 2060 under a net zero scenario, using the NCAR Community Earth System Model (CESM) with online tagging of O<subscript>3</subscript> and its precursors. The results reveal that the global tropospheric O<subscript>3</subscript> burden is likely to decrease by more than 20 %, from 316 Tg in present day to 247 Tg in 2060, under a net zero scenario. The burden of stratospheric O<subscript>3</subscript> in the troposphere is expected to increase from 69 to 77 Tg. The mean lifetime of tropospheric O<subscript>3</subscript> increases by 2 days, ~10 %. Changes in climate under a net zero pathway are relatively small, and only lead to small increases in tropospheric O<subscript>3</subscript>. Over East China, surface O<subscript>3</subscript> increases in winter, due to the weakened titration of O<subscript>3</subscript> by NO associated with reduced anthropogenic NO emissions, and to enhanced stratospheric input. In summer, surface O<subscript>3</subscript> decreases by more than 30 ppbv, and peak concentrations shift from July to May. Local contributions from anthropogenic emissions to surface O<subscript>3</subscript> over East Asia are highest in summer, but drop substantially, from 30 % to 14 %, under a net zero scenario. The contribution of biogenic sources is enhanced, and forms the dominant contributor to future surface O<subscript>3</subscript>, especially in summer, ~40 %. This enhanced contribution is mainly due to the increased O<subscript>3</subscript> production efficiency under lower anthropogenic precursor emissions. Over Eastern China, local anthropogenic contributions decrease from 50 % to 30 %. The decreases in surface O<subscript>3</subscript> are strongly beneficial, and are more than sufficient to counteract the increases in surface O<subscript>3</subscript> observed in China over recent years. This study thus highlights the important co-benefits of net zero policies that target climate change in addressing surface O<subscript>3</subscript> pollution over East Asia. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- Database :
- Complementary Index
- Journal :
- EGUsphere
- Publication Type :
- Academic Journal
- Accession number :
- 165473608
- Full Text :
- https://doi.org/10.5194/egusphere-2023-1592