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.

Atmospheric iodine levels influenced by sea surface emissions of inorganic iodine

Abstract

Naturally occurring bromine- and iodine-containing compounds substantially reduce regional, and possibly even global, tropospheric ozone levels1,2,3,4. As such, these halogen gases reduce the global warming effects of ozone in the troposphere5, and its capacity to initiate the chemical removal of hydrocarbons such as methane. The majority of halogen-related surface ozone destruction is attributable to iodine chemistry2. So far, organic iodine compounds have been assumed to serve as the main source of oceanic iodine emissions1,6,7,8,9. However, known organic sources of atmospheric iodine cannot account for gas-phase iodine oxide concentrations in the lower troposphere over the tropical oceans3,4. Here, we quantify gaseous emissions of inorganic iodine following the reaction of iodide with ozone in a series of laboratory experiments. We show that the reaction of iodide with ozone leads to the formation of both molecular iodine and hypoiodous acid. Using a kinetic box model of the sea surface layer and a one-dimensional model of the marine boundary layer, we show that the reaction of ozone with iodide on the sea surface could account for around 75% of observed iodine oxide levels over the tropical Atlantic Ocean. According to the sea surface model, hypoiodous acid—not previously considered as an oceanic source of iodine—is emitted at a rate ten-fold higher than that of molecular iodine under ambient conditions.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Gaseous I2 and HOI emissions from ozonized iodide solutions and sea water as a function of [O3(g)] and [I(aq)].
Figure 2: Schematic of HOI and I2 production following the reaction of O3 with I at the air–sea interface.
Figure 3: Modelled iodine chemistry at Cape Verde using the 1D model THAMO.

References

  1. Vogt, R., Sander, R., von Glasow, R. & Crutzen, P. J. Iodine chemistry and its role in halogen activation and ozone loss in the marine boundary layer: A model study. J. Atmos. Chem. 32, 375–395 (1999).

    Article  Google Scholar 

  2. Read, K. A. et al. Extensive halogen-mediated ozone destruction over the tropical Atlantic Ocean. Nature 453, 1232–1235 (2008).

    Article  Google Scholar 

  3. Mahajan, A. S. et al. Measurement and modelling of tropospheric reactive halogen species over the tropical Atlantic Ocean. Atmos. Chem. Phys. 10, 4611–4624 (2010).

    Article  Google Scholar 

  4. Jones, C. E. et al. Quantifying the contribution of marine organic gases to atmospheric iodine. Geophys. Res. Lett. 37, L18804 (2010).

    Google Scholar 

  5. Saiz-Lopez, A. et al. Estimating the climate significance of halogen-driven ozone loss in the tropical marine troposphere. Atmos. Chem. Phys. Discuss. 11, 32003–32029 (2011).

    Article  Google Scholar 

  6. Law, K. S. & Sturges, W. T. Scientific Assessment of Ozone Depletion: 2006, Global Ozone Research and Monitoring Project, Report No. 50 Ch. 2 (World Meteorological Organization, 2007).

  7. Liss, P. S. & Slater, P. G. Flux of gases across the air–sea interface. Nature 247, 181–184 (1974).

    Article  Google Scholar 

  8. Davis, D. et al. Potential impact of iodine on tropospheric levels of ozone and other critical oxidants. J. Geophys. Res. 101, 2135–2147 (1996).

    Article  Google Scholar 

  9. Carpenter, L. J. Iodine in the marine boundary layer. Chem. Rev. 103, 4953–4962 (2003).

    Article  Google Scholar 

  10. Garland, J. A. & Curtis, H. Emission of iodine from the sea surface in the presence of ozone. J. Geophys. Res. 86, 3183–3186 (1981).

    Article  Google Scholar 

  11. Sakamoto, Y., Yabushita, A., Kawasaki, M. & Enami, S. Direct emission of I2 molecule and IO radical from the heterogeneous reactions of gaseous ozone with aqueous potassium iodide solution. J. Phys. Chem. A 113, 7707–7713 (2009).

    Article  Google Scholar 

  12. Hayase, S., Yabushita, A. & Kawasaki, M. Heterogeneous reaction of gaseous ozone with aqueous iodide in the presence of aqueous organic species. J. Phys. Chem. A 114, 6016–6021 (2010).

    Article  Google Scholar 

  13. Ganzeveld, L. et al. Atmosphere-ocean ozone exchange: A global modeling study of biogeochemical, atmospheric, and waterside turbulence dependencies. Glob. Biogeochem. Cycles 23, GB4021 (2009).

    Article  Google Scholar 

  14. Clifford, D. & Donaldson, D. J. Direct experimental evidence for a heterogeneous reaction of ozone with bromide at the air–aqueous interface. J. Phys. Chem. A 111, 9809–9814 (2007).

    Article  Google Scholar 

  15. Garland, J. A., Elzerman, A. W. & Penkett, S. A. The mechanism for dry deposition of ozone to seawater surfaces. J. Geophys. Res. 85, 7488–7492 (1980).

    Article  Google Scholar 

  16. Magi, L. et al. Investigation of the uptake rate of ozone and methyl hydroperoxide by water surfaces. J. Phys. Chem. A 101, 4943–4949 (1997).

    Article  Google Scholar 

  17. Rouvière, A., Sosedova, Y. & Ammann, M. Uptake of ozone to deliquesced KI and mixed KI/NaCl Aerosol Particles. J. Phys. Chem. A 114, 7085–7093 (2010).

    Article  Google Scholar 

  18. Davidovits, P. et al. Mass accommodation and chemical reactions at gas–liquid interfaces. Chem. Rev. 106, 1323–1354 (2006).

    Article  Google Scholar 

  19. Guo, Z. N. & Roache, F. Overall mass transfer coefficient for pollutant emissions from small water pools under simulated indoor environmental conditions. Ann. Occup. Hyg. 47, 279–286 (2003).

    Google Scholar 

  20. Johnson, M. T. A numerical scheme to calculate temperature and salinity dependent air–water transfer velocities for any gas. Ocean Sci. 6, 913–932 (2010).

    Article  Google Scholar 

  21. Truesdale, V. W., Luther, G. W. & Canosa-Mas, C. E. Molecular iodine reduction in seawater: An improved rate equation considering organic compounds. Mar. Chem. 48, 143–150 (1995).

    Article  Google Scholar 

  22. Margerum, D. W. et al. Kinetics of the iodine monochloride reaction with iodide measured by the pulsed-accelerated-flow method. Inorg. Chem. 25, 4900–4904 (1986).

    Article  Google Scholar 

  23. Wang, Y. L., Nagy, J. C. & Margerum, D. W. Kinetics of hydrolysis of iodine monochloride measured by the pulsed-accelerated- flow method. J. Am. Chem. Soc. 111, 7838–7844 (1989).

    Article  Google Scholar 

  24. Faria, T., Lengyel, D. B., Epstein, I. R. & Kustin, K. Combined mechanism explaining nonlinear dynamics in bromine(III) and bromine(IV) oxidations of iodide ion. J. Phys. Chem. 97, 1164–1171 (1993).

    Article  Google Scholar 

  25. Reeser, D. I. & Donaldson, D. J. Influence of water surface properties on the heterogeneous reaction between O3(g) and I(aq) . Atmos. Environ. 45, 6116–6120 (2011).

    Article  Google Scholar 

  26. Frew, N. M. et al. Air-sea gas transfer: Its dependence on wind stress, small-scale roughness, and surface films. J. Geophys. Res. 109, C08S17 (2004).

    Article  Google Scholar 

  27. Nightingale, P. D. et al. In situ evaluation of air–sea gas exchange parameterizations using novel conservative and volatile tracers. Glob. Biogeochem. Cycles 14, 373–387 (2000).

    Article  Google Scholar 

  28. Saiz-Lopez, A. et al. Atmospheric chemistry of iodine. Chem. Rev. 112, 1773–1804 (2011).

    Article  Google Scholar 

Download references

Acknowledgements

We acknowledge the UK NERC SOLAS (Surface Ocean Lower Atmosphere) programme for funding and would like to thank J. Lee, University of York, for loan of the O3 generator and monitor. M.D.S. and S.M.M. thank the NERC for the award of PhD studentships. S.M.M. would also like to thank Vanessa Cox for assistance with the University of Leeds experiments.

Author information

Authors and Affiliations

Authors

Contributions

L.J.C. and J.M.C.P. designed the experiments and S.M.M., M.D.S., R.K. and R.W.S. carried them out. L.J.C. designed and implemented the interfacial model and interpreted the data. R.P. developed some of the aqueous iodine mechanism used in the interfacial model and performed aqueous iodine experiments to validate it. J.M.C.P. carried out the atmospheric modelling. J.W. performed the linear regression modelling. L.J.C. prepared the manuscript, with contributions from all authors.

Corresponding authors

Correspondence to Lucy J. Carpenter or John M. C. Plane.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1292 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Carpenter, L., MacDonald, S., Shaw, M. et al. Atmospheric iodine levels influenced by sea surface emissions of inorganic iodine. Nature Geosci 6, 108–111 (2013). https://doi.org/10.1038/ngeo1687

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo1687

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