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Increasing springtime ozone mixing ratios in the free troposphere over western North America

Abstract

In the lowermost layer of the atmosphere—the troposphere—ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases1. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity1. Moreover, tropospheric ozone itself acts as an effective greenhouse gas2. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors3 resulting in widespread increases in ozone concentrations since the late 1800s3,4,5,6,7. At present, east Asia has the fastest-growing ozone precursor emissions8. Much of the springtime east Asian pollution is exported eastwards towards western North America9. Despite evidence that the exported Asian pollution produces ozone10, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s5,11,12. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995–2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes13, with western North America being particularly sensitive to rising Asian emissions14. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA’s compliance with its ozone air quality standard.

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Figure 1: Springtime ozone distributions for 1984, 1995–2008 in the mid-troposphere (3.0–8.0 km), and air mass source regions.
Figure 2: Average 1995–2008 FLEXPART retroplume residence times.

References

  1. The Royal Society. Ground-level Ozone in the 21st century: Future Trends, Impacts and Policy Implications Royal Society policy document 15/08, RS1276, 〈http://royalsociety.org/Report_WF.aspx?pageid=7924&terms=ground-level+ozone〉 (2008)

  2. Intergovernmental Panel on Climate Change. Climate Change 2007—The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, 2007)

  3. Horowitz, L. W. Past, present, and future concentrations of tropospheric ozone and aerosols: methodology, ozone evaluation, and sensitivity to aerosol wet removal. J. Geophys. Res. 111 D22211 10.1029/2005JD006937 (2006)

    ADS  Article  Google Scholar 

  4. Staehelin, J., Thudium, J., Buehler, R., Volz-Thomas, A. & Graber, W. Trends in surface ozone concentrations at Arosa (Switzerland). Atmos. Environ. 28, 75–87 (1994)

    ADS  CAS  Article  Google Scholar 

  5. Oltmans, S. J. et al. Long-term changes in tropospheric ozone. Atmos. Environ. 40, 3156–3173 (2006)

    ADS  CAS  Article  Google Scholar 

  6. Thouret, V. et al. Tropopause referenced ozone climatology and inter-annual variability (1994–2003) from the MOZAIC programme. Atmos. Chem. Phys. 6, 1033–1051 (2006)

    ADS  CAS  Article  Google Scholar 

  7. Zbinden, R. M. et al. Mid-latitude tropospheric ozone columns from the MOZAIC program: climatology and interannual variability. Atmos. Chem. Phys. 6, 1033–1051 (2006)

    ADS  Article  Google Scholar 

  8. van der A, R. J. et al. Trends, seasonal variability and dominant NOx source derived from a ten year record of NO2 measured from space. J. Geophys. Res. 113 D04302 10.1029/2007JD009021 (2008)

    ADS  CAS  Article  Google Scholar 

  9. Stohl, A., Eckhardt, S., Forster, C., James, P. & Spichtinger, N. On the pathways and timescales of intercontinental air pollution transport. J. Geophys. Res. 107 (D23). 4684 10.1029/2001JD001396 (2002)

    CAS  Article  Google Scholar 

  10. Hudman, R. C. et al. Ozone production in transpacific Asian pollution plumes and implications for ozone air quality in California. J. Geophys. Res. 109 D23S10 10.1029/2004JD004974 (2004)

    ADS  CAS  Article  Google Scholar 

  11. Jaffe, D. & Ray, J. Increase in surface ozone at rural sites in the western US. Atmos. Environ. 41, 5452–5463 (2007)

    ADS  CAS  Article  Google Scholar 

  12. Schnadt Poberaj, C. et al. Long-term changes in UT/LS ozone between the late 1970s and the 1990s deduced from the GASP and MOZAIC aircraft programs and from ozonesondes. Atmos. Chem. Phys. 9, 5343–5369 (2009)

    ADS  CAS  Article  Google Scholar 

  13. Stevenson, D. S. et al. Multimodel ensemble simulations of present-day and near-future tropospheric ozone. J. Geophys. Res. 111 D08301 10.1029/2005JD006338 (2006)

    ADS  CAS  Article  Google Scholar 

  14. Jacob, D. J., Logan, J. A. & Murti, P. P. Effect of rising Asian emissions on surface ozone in the United States. Geophys. Res. Lett. 26, 2175–2178 (1999)

    ADS  CAS  Article  Google Scholar 

  15. Schultz, M. & Rast, S. (eds) RETRO Emission Data Sets and Methodologies for Estimating Emissions, Work Package 1, Deliverable D1-6 Report from REanalysis of the TROpospheric chemical composition over the past 40 years. 1–144 〈http://retro.enes.org/pub_reports.shtml〉 (2007)

    Google Scholar 

  16. Zhang, Q. et al. Asian emissions in 2006 for the NASA INTEX-B mission. Atmos. Chem. Phys. 9, 5131–5153 (2009)

    ADS  CAS  Article  Google Scholar 

  17. US Environmental Protection Agency. National Emissions Inventory (NEI) Air Pollutant Emissions Trends Datahttp://www.epa.gov/ttnchie1/trends/〉 (2009)

  18. Parrish, D. D., Millet, D. B. & Goldstein, A. H. Increasing ozone in marine boundary layer inflow at the west coasts of North America and Europe. Atmos. Chem. Phys. 9, 1303–1323 (2009)

    ADS  CAS  Article  Google Scholar 

  19. Fiore, A. M. et al. Multimodel estimates of intercontinental source-receptor relationships for ozone pollution. J. Geophys. Res. 114 D04301 10.1029/2008JD010816 (2009)

    ADS  CAS  Article  Google Scholar 

  20. Tarasick, D. W., Fioletov, V. E., Wardle, D. I., Kerr, J. B. & Davies, J. Changes in the vertical distribution of ozone over Canada from ozonesondes: 1980–2001. J. Geophys. Res. 110 D02304 10.1029/2004JD004643 (2005)

    ADS  CAS  Article  Google Scholar 

  21. Oltmans, S. J., Lefohn, A. S., Harris, J. M. & Shadwick, D. S. Background ozone levels of air entering the west coast of the US and assessment of longer-term changes. Atmos. Environ. 42, 6020–6038 (2008)

    ADS  CAS  Article  Google Scholar 

  22. Parrish, D. D. et al. Changes in the photochemical environment of the temperate North Pacific troposphere in response to increased Asian emissions. J. Geophys. Res. 109 D23S18 10.1029/2004JD004978 (2004)

    ADS  CAS  Article  Google Scholar 

  23. Luke, W. T., Dickerson, R. R., Ryan, W. F., Pickering, K. E. & Nunnermacker, L. J. Tropospheric chemistry over the lower Great Plains of the United States. 2: Trace gas profiles and distributions. J. Geophys. Res. 97, 20647–20670 (1992)

    ADS  Article  Google Scholar 

  24. Luke, W. T. Reactive Nitrogen Compounds in the Troposphere: Observations, Transport, and Photochemistry PhD dissertation, Univ. Maryland (1990)

    Google Scholar 

  25. Lefohn, A. S., Shadwick, D. & Oltmans, S. J. Characterizing long-term changes in surface ozone levels in the United States (1980–2005). Atmos. Environ. 42, 8252–8262 (2008)

    ADS  CAS  Article  Google Scholar 

  26. Chou, C. C.-K., Liu, S. C., Lin, C.-Y., Shiu, C.-J. & Chang, K.-H. The trend of surface ozone in Taipei, Taiwan, and its causes: implications for ozone control strategies. Atmos. Environ. 40, 3898–3908 (2006)

    ADS  CAS  Article  Google Scholar 

  27. Ding, A. J., Wang, T., Thouret, V., Cammas, J.-P. & Nédélec, P. Tropospheric ozone climatology over Beijing: analysis of aircraft data from the MOZAIC program. Atmos. Chem. Phys. 8, 1–13 (2008)

    ADS  CAS  Article  Google Scholar 

  28. Tanimoto, H. Increase in springtime tropospheric ozone at a mountainous site in Japan for the period 1998–2006. Atmos. Environ. 43, 1358–1363 (2009)

    ADS  CAS  Article  Google Scholar 

  29. Zhang, L. et al. Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations. Atmos. Chem. Phys. 8, 6117–6136 (2008)

    ADS  CAS  Article  Google Scholar 

  30. Logan, J. et al. Trends in the vertical distribution of ozone: a comparison of two analyses of ozonesonde data. J. Geophys. Res. 104, 26373–26399 (1999)

    ADS  CAS  Article  Google Scholar 

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Acknowledgements

This work was supported in part by NOAA’s Climate Goal Program. We acknowledge the support of MOZAIC by the European Communities, EADS, Airbus and the airlines (Lufthansa, Austrian, Air France) who have carried MOZAIC equipment free of charge since 1994. B. Ridley, NCAR (retired), measured ozone from the NCAR C-130 during TOPSE. G. L. Gregory, NASA (retired), measured ozone from the Convair CV-990 during CITE-1C. M. Proffitt, NOAA (retired) measured ozone from the NASA ER2 during STRAT and POLARIS, and measured ozone from the NASA WB57 during WAM. PACDEX ozone data were provided by NCAR/EOL under sponsorship of the National Science Foundation (http://data.eol.ucar.edu/). EDGAR (http://www.mnp.nl/edgar) is a product of the National Institute for Public Health and the Netherlands Organisation for Applied Scientific Research and is part of the Global Emissions Inventory Activity of IGBP/IGAC. Finally we thank R. Dickerson for providing the mean ozone values for June 1985 and May–June 1986.

Author Contributions O.R.C., D.D.P., A.S. and M.T conceived the study and guided its development. O.R.C. merged the ozone datasets and ran the PDM with assistance from A.S. O.R.C. analysed the data and wrote the text. P.N., V.T., J.P.C., S.J.O., B.J.J., D.T., T.L., I.S.M., D.J., R.G., J.S., T.R., K.A., T.C., A.W. and M.A.A. made the ozone measurements and guided interpretation of the datasets.

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Correspondence to O. R. Cooper.

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This file contains Supplementary Methods, a Supplementary Discussion, Supplementary References, Supplementary Table S1 and Supplementary Figures S1-S5 with Legends. (PDF 2717 kb)

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Cooper, O., Parrish, D., Stohl, A. et al. Increasing springtime ozone mixing ratios in the free troposphere over western North America. Nature 463, 344–348 (2010). https://doi.org/10.1038/nature08708

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