Arctic tropospheric ozone: assessment of current knowledge and model performance

• Main Authors: Whaley, Cynthia, Law, Kathy S., Hjorth, Jens Liengaard, Skov, Henrik, Arnold, Stephen, Langner, Joakim, Pernov, Jakob Boyd, Chien, Rong-You, Christensen, Jesper, Deushi, Makoto, Dong, Xinyi, Faluvegi, Gregory, Flanner, Mark, Fu, Joshua, Gauss, Michael, Im, Ulas, Marelle, Louis, Onishi, Tatsuo, Oshima, Naga, Plummer, David, Pozzoli, Luca, Raut, Jean-Christophe, Skeie, Ragnhild, Thomas, Manu, Tsigaridis, Kostas, Tsyro, Svetlana, Turnock, Steven, von Salzen, Knut, Tarasick, David
• Other Authors: Environment and Climate Change Canada, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), iCLIMATE Aarhus University Interdisciplinary Centre for Climate Change, Aarhus University Aarhus, Institute for Climate and Atmospheric Science Leeds (ICAS), School of Earth and Environment Leeds (SEE), University of Leeds-University of Leeds, Swedish Meteorological and Hydrological Institute (SMHI), The University of Tennessee Knoxville, Meteorological Research Institute Tsukuba (MRI), Japan Meteorological Agency (JMA), NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Center for Climate Systems Research New York (CCSR), Columbia University New York, Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan Ann Arbor, University of Michigan System-University of Michigan System, Norwegian Meteorological Institute Oslo (MET), European Commission - Joint Research Centre Ispra (JRC), FINCONS SPA, Center for International Climate and Environmental Research Oslo (CICERO), University of Oslo (UiO), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office Exeter
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; Eureka; Human health
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03682231; https://hal-insu.archives-ouvertes.fr/insu-03682231/document; https://hal-insu.archives-ouvertes.fr/insu-03682231/file/acp-2022-319.pdf; https://doi.org/10.5194/acp-2022-319

International audience As the third most important greenhouse gas (GHG) after CO2 and methane, tropospheric ozone (O3) is also an air pollutant causing damage to human health and ecosystems. This study brings together recent research on observations and modeling of tropospheric O3 in the Arctic, a rapidly warming and sensitive environment. At different locations in the Arctic, the observed surface O3 seasonal cycles are quite different. Coastal Arctic locations, for example, have a minimum in the springtime due to O3 depletion events resulting from surface bromine chemistry. In contrast, other Arctic locations have a maximum in the spring. The 12 state-of-the-art models used in this study lack the surface halogen chemistry needed to simulate coastal Arctic surface O3 depletion in the springtime, however, the multi-model median (MMM) has accurate seasonal cycles at non-coastal Arctic locations. There is a large amount of variability among models, which has been reported previously, and we show that there continues to be no convergence among models, nor improved accuracy in simulating tropospheric O3 and its precursor species. The MMM underestimates Arctic surface O3 by 5% to 15% depending on the location. The vertical distribution of tropospheric O3 is studied from recent ozonesonde measurements and the models. The models are highly variable, simulating free-tropospheric O3 within a range of +/-50% depending on the model and the altitude. The MMM performs best, within +/-8% at most locations and seasons. However, nearly all models overestimate O3 near the tropopause (~300 hPa or ~8 km), likely due to ongoing issues with underestimating the altitude of the tropopause and excessive downward transport of stratospheric O3 at high latitudes. For example, the MMM is biased high by about 20% at Eureka. Observed and simulated O3 precursors (CO, NOx and reservoir PAN) are evaluated throughout the troposphere. Models underestimate wintertime CO everywhere, likely due to a combination of underestimating CO emissions and ...