Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Mass-independent fractionation of mercury isotopes in Arctic snow driven by sunlight

Abstract

After polar sunrise in the Arctic, sunlight-induced reactions convert gaseous elemental mercury into compounds that are rapidly deposited to the snowpack. These atmospheric mercury depletion events occur repeatedly until snowmelt1,2. Following deposition, the mercury can be reduced by sunlight-induced reactions and emitted as a gas3,4,5,6, or can be retained in the snowpack7,8, where it may affect Arctic ecosystems following snowmelt. However, the proportion of mercury that remains in the snowpack is uncertain. Here, we measured the mercury isotopic composition of snow samples collected during an atmospheric mercury depletion event in Barrow, Alaska. We report large negative mass-independent fractionation of mercury isotopes in the Arctic snow. Results from a flux chamber experiment suggest that mass-independent fractionation is coupled to the re-emission of elemental mercury to the atmosphere, and is triggered by sunlight-induced reactions. On the basis of the above, we estimate that photochemical reactions triggered the release of a significant portion of the mercury deposited during this atmospheric mercury depletion event.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Mass-dependent and mass-independent mercury isotope compositions of snow samples, chamber experiment samples and gaseous samples.
Figure 2: Mass-independent mercury isotope compositions of snow samples and chamber experiment samples.
Figure 3: Rayleigh fractionation models showing mercury isotope changes in snow and emitted gas.

References

  1. 1

    Lindberg, S. E. et al. Dynamic oxidation of gaseous mercury in the troposphere at polar sunrise. Environ. Sci. Technol. 36, 1245–1256 (2002).

    Article  Google Scholar 

  2. 2

    Steffen, A., Schroeder, W., Macdonald, R., Poissant, L. & Konoplev, A. Mercury in the Arctic atmosphere: An analysis of eight years of measurements on GEM at Alert (Canada) and a comparison with observations at Amderma (Russia) and Kuujjuarapik (Canada). Sci. Total Environ. 342, 185–198 (2005).

    Article  Google Scholar 

  3. 3

    Lalonde, J., Poulain, A. J. & Amyot, M. The role of mercury redox reactions in snow on snow-to-air mercury transfer. Environ. Sci. Technol. 36, 174–178 (2002).

    Article  Google Scholar 

  4. 4

    Poulain, A. J. et al. Redox transformations of mercury in an Arctic snowpack at springtime. Atmos. Environ. 38, 6763–6774 (2004).

    Article  Google Scholar 

  5. 5

    Steffen, A., Schroeder, W., Bottenheim, J., Narayan, J. & Fuentes, J. D. Atmospheric mercury concentrations: Measurements and profiles near snow and ice surfaces in the Canadian Arctic during Alert 2000. Atmos. Environ. 36, 2653–2661 (2002).

    Article  Google Scholar 

  6. 6

    Kirk, J. L., St Louis, V. L. & Sharp, M. J. Rapid reduction and reemission of mercury deposited into snowpacks during atmospheric mercury depletion events at Churchill, Manitoba, Canada. Environ. Sci. Technol. 40, 7590–7596 (2006).

    Article  Google Scholar 

  7. 7

    Dommergue, A., Ferrari, C. P., Gauchard, P.-A. & Boutron, C. F. The fate of mercury species in a sub-arctic snowpack during snowmelt. Geophys. Res. Lett. 30, 1621–1624 (2003).

    Article  Google Scholar 

  8. 8

    St Louis, V. L. et al. Methylated mercury species in Canadian high arctic marine surface waters and snowpacks. Environ. Sci. Technol. 41, 6433–6441 (2007).

    Article  Google Scholar 

  9. 9

    Zheng, W., Foucher, D. & Hintelmann, H. Mercury isotope fractionation during volatilization of Hg(0) from solution into the gas phase. J. Anal. At. Spectrom. 22, 1097–1104 (2007).

    Article  Google Scholar 

  10. 10

    Sherman, L. S. et al. Mercury isotopic composition of hydrothermal systems in the Yellowstone Plateau volcanic field and Guaymas Basin sea-floor rift. Earth. Planet. Sci. Lett. 279, 86–96 (2009).

    Article  Google Scholar 

  11. 11

    Kritee, K., Blum, J. D., Johnson, M. W., Bergquist, B. A. & Barkay, T. Mercury stable isotope fractionation during reduction of Hg(II) to Hg(0) by mercury resistant microorganisms. Environ. Sci. Technol. 41, 1889–1895 (2007).

    Article  Google Scholar 

  12. 12

    Blum, J. D. & Bergquist, B. A. Reporting the variations in the natural isotopic composition of mercury. Anal. Bioanal. Chem. 388, 353–359 (2007).

    Article  Google Scholar 

  13. 13

    Bergquist, B. A. & Blum, J. D. Mass-dependent and mass-independent fractionation of Hg isotopes by photo-reduction in aquatic systems. Science 318, 417–420 (2007).

    Article  Google Scholar 

  14. 14

    Biswas, A., Blum, J. D., Bergquist, B. A., Keeler, G. J. & Zhouqing, X. Natural mercury isotope variation in coal deposits and organic soils. Environ. Sci. Technol. 42, 8303–8309 (2008).

    Article  Google Scholar 

  15. 15

    Ghosh, S., Xu, Y., Humayun, M. & Odom, L. Mass-independent fractionation of mercury isotopes in the environment. Geochem. Geophys. Geosyst. 9, Q03004 (2008).

    Article  Google Scholar 

  16. 16

    Hintelmann, H., Foucher, D., Telmer, K., Zheng, J. & Yamada, M. Hg isotope fractionation in sediment cores. Geochim. Cosmochim. Acta 72, A379 (2008).

    Google Scholar 

  17. 17

    Jackson, T. A., Whittle, D. M., Evans, M. S. & Muir, D. C. G. Evidence for mass-independent and mass-dependent fractionation of the stable isotopes of mercury by natural processes in aquatic ecosystems. Appl. Geochem. 23, 547–571 (2008).

    Article  Google Scholar 

  18. 18

    Schauble, E. A. Role of nuclear volume in driving equilibrium stable isotope fractionation of mercury, thallium, and other very heavy elements. Geochim. Cosmochim. Acta 71, 2170–2189 (2007).

    Article  Google Scholar 

  19. 19

    Bigeleisen, J. Nuclear size and shape effects in chemical reactions. Isotope chemistry of the heavy elements. J. Am. Chem. Soc. 118, 3676–3680 (1996).

    Article  Google Scholar 

  20. 20

    Buchachenko, A. L. Magnetic isotope effect: Nuclear spin control of chemical reactions. J. Phys. Chem. 105, 9995–10011 (2001).

    Article  Google Scholar 

  21. 21

    Johnson, K. P., Blum, J. D., Keeler, G. J. & Douglas, T. A. Investigation of the deposition and emission of mercury in arctic snow during an atmospheric mercury depletion event. J. Geophys. Res. 113, D17304 (2008).

    Article  Google Scholar 

  22. 22

    Lu, J. Y., Schroeder, W. H., Barrie, L. A. & Steffen, A. Magnification of atmospheric mercury deposition to polar regions in springtime: The link to tropospheric ozone depletion chemistry. Geophys. Res. Lett. 28, 3219–3222 (2001).

    Article  Google Scholar 

  23. 23

    Tackett, P. J. et al. A study of the vertical scale of halogen chemistry in the Arctic troposphere during Polar Sunrise at Barrow, Alaska. J. Geophys. Res. 112, D07306 (2007).

    Article  Google Scholar 

  24. 24

    Banic, C. M. et al. Vertical distribution of gaseous elemental mercury in Canada. J. Geophys. Res. 108, 4264–4277 (2003).

    Article  Google Scholar 

  25. 25

    Douglas, T. A. et al. Influence of snow and ice crystal formation and accumulation on mercury deposition to the arctic. Environ. Sci. Technol. 42, 1542–1551 (2008).

    Article  Google Scholar 

  26. 26

    Carignan, J., Estrade, N., Sonke, J. E. & Donard, O. F. X. Odd isotope deficits in atmospheric Hg measured in lichens. Environ. Sci. Technol. 43, 5660–5664 (2009).

    Article  Google Scholar 

  27. 27

    Lalonde, J. D., Amyot, M., Doyon, M.-R. & Auclair, J.-C. Photo-induced Hg(II) reduction in snow from the remote and temperate experimental Lakes area (Ontario, Canada). J. Geophys. Res. 108, 4200–4207 (2003).

    Article  Google Scholar 

  28. 28

    Estrade, N., Carignan, J., Sonke, J. E. & Donard, O. F. X. Mercury isotope fractionation during liquid–vapour evaporation experiments. Geochim. Cosmochim. Acta 73, 2693–2711 (2009).

    Article  Google Scholar 

  29. 29

    Ferrari, C. P. et al. Snow-to-air exchanges of mercury in an Arctic seasonal snow pack in Ny-Alesund, Svalbard. Atmos. Environ. 39, 7633–7645 (2005).

    Article  Google Scholar 

  30. 30

    King, M. D. & Simpson, W. R. Extinction of ultraviolet radiation in Arctic snow at Alert, Canada (82 N). J. Geophys. Res. 106, 12499–12507 (2001).

    Article  Google Scholar 

Download references

Acknowledgements

Financial support for this research was provided by the National Science Foundation Office of Polar Programs (Grants ARC-0435989 and ARC-0435893). L.S.S. is financially supported by a National Defense Science and Engineering Graduate Fellowship through the Department of Defense, Office of Naval Research. We are grateful to M. W. Johnson, L. Alvarez-Aviles, M. Sturm, R. Prevost, P. W. Sherman and the members of BEIGL for assistance and helpful discussions.

Author information

Affiliations

Authors

Contributions

J.D.B. initiated this study along with T.A.D. and G.J.K. K.P.J., J.D.B., T.A.D., J.A.B. and G.J.K. collected the snow samples and conducted the chamber experiment. L.S.S. and K.P.J. conducted the laboratory analyses and L.S.S. wrote the manuscript. All authors contributed to discussions of results and conclusions.

Corresponding author

Correspondence to Laura S. Sherman.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sherman, L., Blum, J., Johnson, K. et al. Mass-independent fractionation of mercury isotopes in Arctic snow driven by sunlight. Nature Geosci 3, 173–177 (2010). https://doi.org/10.1038/ngeo758

Download citation

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing