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Formation and fate of oxidized mercury in the upper troposphere and lower stratosphere


Mercury contamination affects many aquatic ecosystems1. The atmosphere is the main transport route for this toxicant2. According to aircraft measurements, the upper troposphere and lower stratosphere are depleted in gaseous elemental mercury3,4 but enriched in oxidized, particle-bound mercury5,6. It is therefore assumed that mercury is oxidized in the stratosphere, and then incorporated into stratospheric aerosols6. However, direct evidence for mercury oxidation in the stratosphere is missing. Here, we present simultaneous measurements of elemental and oxidized mercury concentrations in air of stratospheric origin, collected during an aircraft campaign over North America and Europe in 2010. We show that levels of oxidized mercury are strongly correlated with tracers of stratospheric air. Concentrations of total and elemental mercury, in contrast, are negatively correlated with these tracers. Together, the findings indicate that elemental mercury is oxidized in stratospheric air masses. We develop a numerical model of atmospheric mercury, based on the assumption that mercury is oxidized in the upper troposphere and lower stratosphere. The resultant vertical profiles—which depict a rapid decline in mercury concentrations with increasing stratospheric height—resemble those seen in other studies, and indicate that mercury has a relatively short stratospheric lifetime. We suggest that following oxidation, mercury is removed from the stratosphere by sedimentation and entrainment processes common to all stratospheric particles.

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Figure 1: Mercury and ozone during a 5 November 2011 flight through stratosphere-influenced air.
Figure 2: Hg(0) versus Hg(II) on 5 November 2011.
Figure 3: Modelled vertical profile of mercury forms.
Figure 4: Mercury versus ozone measured in this study and during other aircraft campaigns.


  1. Selin, N. E. Global biogeochemical cycling of mercury: A review. Annu. Rev. Environ. Res. 34, 43–63 (2009).

    Article  Google Scholar 

  2. Fitzgerald, W. F., Engstrom, D. R., Mason, R. P. & Nater, E. A. The case for atmospheric mercury contamination in remote areas. Environ. Sci. Technol. 32, 1–7 (1998).

    Article  Google Scholar 

  3. Talbot, R., Mao, H., Scheuer, E., Dibb, J. & Avery, M. Total depletion of Hg in the upper troposphere–lower stratosphere. Geophys. Res. Lett. 34, L23804 (2007).

    Article  Google Scholar 

  4. Slemr, F. et al. Gaseous mercury distribution in the upper troposphere and lower stratosphere observed onboard the CARIBIC passenger aircraft. Atmos. Chem. Phys. 9, 1957–1969 (2009).

    Article  Google Scholar 

  5. Murphy, D., Thomson, D. & Mahoney, M. In situ measurements of organics, meteoritic material, mercury, and other elements in aerosols at 5 to 19 km. Science 282, 1664–1669 (1998).

    Article  Google Scholar 

  6. Murphy, D., Hudson, P., Thomson, D., Sheridan, P. & Wilson, J. Observations of mercury-containing aerosols. Environ. Sci. Technol. 40, 3163–3167 (2006).

    Article  Google Scholar 

  7. Swartzendruber, P. C. et al. Observations of reactive gaseous mercury in the free troposphere at the Mt. Bachelor Observatory. J. Geophys. Res. 111, D24301 (2006).

    Article  Google Scholar 

  8. Swartzendruber, P. C., Jaffe, D. A. & Finley, B. Development and first results of an aircraft-based, high time resolution technique for gaseous elemental and reactive (oxidized) gaseous mercury. Environ. Sci. Technol. 43, 7484–7489 (2009).

    Article  Google Scholar 

  9. Fain, X., Obrist, D., Hallar, A. G., McCubbin, I. & Rahn, T. High levels of reactive gaseous mercury observed at a high elevation research laboratory in the Rocky Mountains. Atmos. Chem. Phys. 9, 8049–8060 (2009).

    Article  Google Scholar 

  10. Rutter, A. P. & Schauer, J. J. The effect of temperature on the gas-particle partitioning of reactive mercury in atmospheric aerosols. Atmos. Environ. 41, 8647–8657 (2007).

    Article  Google Scholar 

  11. Mao, H. et al. Arctic mercury depletion and its quantitative link with halogens. J. Atmos. Chem. 65, 1–26 (2010).

    Article  Google Scholar 

  12. Swartzendruber, P. C. et al. Vertical distribution of mercury, CO, ozone, and aerosol scattering coefficient in the Pacific Northwest during the spring 2006 INTEX-B campaign. J. Geophys. Res. 113, D10305 (2008).

    Article  Google Scholar 

  13. Holmes, C. D. et al. Global atmospheric model for mercury including oxidation by bromine atoms. Atmos. Chem. Phys. 10, 12037–12057 (2010).

    Article  Google Scholar 

  14. Murphy, D. & Thomson, D. Halogen ions and NO in the mass spectra of aerosols in the upper troposphere and lower stratosphere. Geophys. Res. Lett. 27, 3217–3220 (2000).

    Article  Google Scholar 

  15. Dorf, M. et al. Bromine in the tropical troposphere and stratosphere as derived from balloon-borne BrO observations. Atmos. Chem. Phys. 8, 7265–7271 (2008).

    Article  Google Scholar 

  16. Skov, H. et al. Fate of elemental mercury in the Arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the Arctic. Environ. Sci. Technol. 38, 2373–2382 (2004).

    Article  Google Scholar 

  17. Rasch, P. J. et al. An overview of geoengineering of climate using stratospheric sulphate aerosols. Phil. Trans. R. Soc. A 366, 4007–4037 (2008).

    Article  Google Scholar 

  18. Menzies, R. T. & Tratt, D. M. Evidence of seasonally dependent stratosphere–troposphere exchange and purging of lower stratospheric aerosol from a multiyear lidar data set. J. Geophys. Res. 100, 3139–3148 (1995).

    Article  Google Scholar 

  19. Zhao, J., Turco, R. P. & Toon, O. B. A model simulation of Pinatubo volcanic aerosols in the stratosphere. J. Geophys. Res. 100, 7315–7328 (1995).

    Article  Google Scholar 

  20. Notholt, J. et al. Enhanced upper tropical tropospheric COS: Impact on the stratospheric aerosol layer. Science 300, 307–310 (2003).

    Article  Google Scholar 

  21. Wilson, J. C. et al. Steady-state aerosol distributions in the extra-tropical, lower stratosphere and the processes that maintain them. Atmos. Chem. Phys. 8, 6617–6626 (2008).

    Article  Google Scholar 

  22. Barkley, M. P., Palmer, P. I., Boone, C. D., Bernath, P. F. & Suntharalingam, P. Global distributions of carbonyl sulfide in the upper troposphere and stratosphere. Geophys. Res. Lett. 35, L14810 (2008).

    Article  Google Scholar 

  23. Selin, N. E. & Jacob, D. J. Seasonal and spatial patterns of mercury wet deposition in the United States: Constraints on the contribution from North American anthropogenic sources. Atmos. Environ. 42, 5193–5204 (2008).

    Article  Google Scholar 

  24. Weiss-Penzias, P., Gustin, M. S. & Lyman, S. N. Observations of speciated atmospheric mercury at three sites in Nevada: Evidence for a free tropospheric source of reactive gaseous mercury. J. Geophys. Res. 114, D14302 (2009).

    Article  Google Scholar 

  25. Dibb, J. E. et al. Estimation of stratospheric input to the Arctic troposphere: 7Be and 10Be in aerosols at Alert, Canada. J. Geophys. Res. 99, 12855–12864 (1994).

    Article  Google Scholar 

  26. Zanis, P. et al. An estimate of the impact of stratosphere-to-troposphere transport (STT) on the lower free tropospheric ozone over the Alps using 10Be and 7Be measurements. J. Geophys. Res. 108, 8520–8529 (2003).

    Article  Google Scholar 

  27. Seo, K. & Bowman, K. P. Lagrangian estimate of global stratosphere–troposphere mass exchange. J. Geophys. Res. 107, 4555–4563 (2002).

    Article  Google Scholar 

  28. Ridley, B. A., Grahek, F. E. & Walega, J. G. A small high-sensitivity, medium-response ozone detector suitable for measurements from light aircraft. J. Atmos. Oceanic Technol. 9, 142–148 (1992).

    Article  Google Scholar 

  29. Gassó, S. & Hegg, D. A. Comparison of columnar aerosol optical properties measured by the MODIS airborne simulator with in situ measurements: A case study. Remote Sens. Environ. 66, 138–152 (1998).

    Article  Google Scholar 

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This study was financially supported by the US National Science Foundation. We thank the CARIBIC team (especially F. Slemr and R. Ebinghaus) for providing us with CARIBIC data ( We thank R. Talbot at the University of Houston for access to data from INTEX-B and ARCTAS. We are grateful for the efforts of numerous technicians, engineers and scientists at NCAR’s Research Aviation Facility who were essential to the success of this work.

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S.N.L. participated in study design, collected and analysed data and is the primary author of the manuscript. D.A.J. led the study and contributed substantially to all aspects of it, including manuscript preparation.

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Correspondence to Seth N. Lyman.

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The authors declare no competing financial interests.

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Lyman, S., Jaffe, D. Formation and fate of oxidized mercury in the upper troposphere and lower stratosphere. Nature Geosci 5, 114–117 (2012).

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