Abstract
As ozone air quality standards are tightened, the portion of the standard taken up by background ozone (BGO) increases. BGO is the ozone that would be observed in the absence of anthropogenic emissions. BGO can be a major, sometimes dominant, contribution to overall ozone. BGO originates from noncontrollable sources (e.g., wildfires, stratosphere-troposphere exchange, non-domestic pollution) and can vary significantly by region, elevation, and season, leading to high uncertainty in BGO contributions. In this work, US BGO is first quantified using a chemical transport model, specifically the Community Multiscale Air Quality (CMAQ) model, with US anthropogenic emissions set to zero. A method of adjusting for model bias in the estimation of BGO is developed that fuses model results with observations. This method uses observational and modelled data to develop functions of space, time, and meteorology that relate CMAQ-simulated base case (using estimated emissions) and CMAQ-modelled US BGO (no US anthropogenic emissions) to the observations. Separate adjustment factors are developed for locally formed and background ozone. This allows for calculating both an adjusted US BGO and the amount of ozone formed from anthropogenic emissions that better align with observations and elucidation of the key influences and sources of bias for these two sources of ozone. The effects of boundary conditions on BGO estimates and model bias is also examined. Application of this adjustment factor method improves agreement between BGO estimated with two different sets of boundary conditions from r = 0.58 for the original modelled values to r = 0.85 for the adjusted values.
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References
Jaffe, D. A., Cooper, O. R., Fiore, A. M., Henderson, B. H., Tonnesen, G. S., Russell, A. G., Henze, D. K., Langford, A. O., Lin, M, & Moore, T. (2018). Scientific assessment of background ozone over the U.S.: Implications for air quality management. Elementa: Science of the Anthropocene, 6, 56. https://doi.org/10.1525/elementa.309
Zhang, L., Jacob, D. J., Downey, N. V., Wood, D. A., Blewitt, D., Carouge, C. C., van Donkelaar, A., Jones, D. B. A., Murray, L. T., & Wang, Y. (2011). Improved estimate of the policy-relevant background ozone in the United States using the GEOS-Chem global model with 1/2° × 2/3° horizontal resolution over North America. Atmospheric Environment, 45, 6769–6776. https://doi.org/10.1016/j.atmosenv.2011.07.054
Acknowledgements
We would like to thank US EPA for providing boundary conditions from a Hemispheric CMAQ simulation. We would also like to acknowledge support from the Phillips 66 Company and NASA as part of their HAQAST program.
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Questioner: Pius Lee.
Question: Can you give an explanation about the sample size of around 397,000? It seems a little small for me in representativeness of the vast variabilities of background influence and multiple year variabilities, wet/dry years, wildfire active/inactive years.
Answer: The sample size of about 397,000 is the total number of model-observation pairs that we have available for the 2017 annual simulation. We could increase the sample size by extending to a multi-year simulation, and we do have plans to extend this work at least to 2016 in addition to what we have done here.
Questioner: Peter Builtjes.
Question: Did you model or estimate the natural background of ozone, without any anthropogenic emissions?
Answer: We did not model the natural background ozone. Others (e.g. Zhang et al., 2011) have modeled the natural background and have found that it is on average approximately 20Â ppb over the US, though it does vary seasonally and geographically.
Questioner: Saravanan Arunachalam.
Question: When you used the hemispheric CMAQ boundary conditions from EPA, did you use hourly boundary conditions or some temporal means?
Answer: We used hourly boundary conditions from the hemispheric CMAQ simulation.
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Skipper, T.N., Odman, M.T., Hu, Y., Vasilakos, P., Russell, A.G. (2021). Improved Estimation of Background Ozone and Emission Impacts Using Chemical Transport Modeling and Data Fusion. In: Mensink, C., Matthias, V. (eds) Air Pollution Modeling and its Application XXVII. ITM 2019. Springer Proceedings in Complexity. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-63760-9_13
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DOI: https://doi.org/10.1007/978-3-662-63760-9_13
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