Journal of Atmospheric Chemistry

, Volume 32, Issue 3, pp 375–395 | Cite as

Iodine Chemistry and its Role in Halogen Activation and Ozone Loss in the Marine Boundary Layer: A Model Study

  • Rainer Vogt
  • Rolf Sander
  • Roland von Glasow
  • Paul J. Crutzen


A detailed set of reactions treating the gas and aqueous phase chemistry of the most important iodine species in the marine boundary layer (MBL) has been added to a box model which describes Br and Cl chemistry in the MBL. While Br and Cl originate from seasalt, the I compounds are largely derived photochemically from several biogenic alkyl iodides, in particular CH2I2, CH2ClI, C2H5I, C3H7I, or CH3I which are released from the sea. Their photodissociation produces some inorganic iodine gases which can rapidly react in the gas and aqueous phase with other halogen compounds. Scavenging of the iodine species HI, HOI, INO2, and IONO2 by aerosol particles is not a permanent sink as assumed in previous modeling studies. Aqueous-phase chemical reactions can produce the compounds IBr, ICl, and I2, which will be released back into the gas phase due to their low solubility. Our study, although highly theoretical, suggests that almost all particulate iodine is in the chemical form of IO-3. Other aqueous-phase species are only temporary reservoirs and can be re-activated to yield gas phase iodine. Assuming release rates of the organic iodine compounds which yield atmospheric concentrations similar to some measurements, we calculate significant concentrations of reactive halogen gases. The addition of iodine chemistry to our reaction scheme has the effect of accelerating photochemical Br and Cl release from the seasalt. This causes an enhancement in ozone destruction rates in the MBL over that arising from the well established reactions O(1D) + H2O → 2OH, HO2 + O3 → OH + 2O2, and OH + O3 → HO2 + O2. The given reaction scheme accounts for the formation of particulate iodine which is preferably accumulated in the smaller sulfate aerosol particles.

aerosol iodine chemistry halogen chemistry marine boundary layer modeling ozone loss sea salt 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alicke, B., Hebestreit, K., Platt, U., Carpenter, L., Sturges, W. T., 1998: Measurements of tropospheric iodine oxide in mid-latitudes, Paper presented at EGS XXIII General Assembly, Nice, France 20–24, 1998, Annales Geophysicae Supplement II 16, C716.Google Scholar
  2. Aranda, A., Le Bras, G., Laverdet, G., and Poulet, G., 1997: The BrO + CH3O2 reaction: Kinetics and role in the atmospheric ozone budget, Geophys. Res. Lett. 24, 2745–2748.Google Scholar
  3. Bauer, D., Ingham, T., Carl, S. A., Moortgat, G. K., and Crowley, J. N., 1998: Ultra-violett-visible absorption cross sections of gaseous HOI and its photolysis at 355 nm, J. Phys. Chem. A 102, 2857–2864.Google Scholar
  4. Bedjanian, Y., Le Bras, G., and Poulet, G., 1997: Kinetics and mechanism of the IO + ClO reaction, J. Phys. Chem. A 101, 4088–4096.Google Scholar
  5. Bloss, W. J., Rowley, D. M., Cox, R. A., and Jones, R. L., 1998: Kinetics and photochemical studies of iodine oxide chemistry, Paper presented at EGS XXIII General Assembly, Nice, France 20–24, 1998, Annales Geophysicae Supplement II 16, C717.Google Scholar
  6. Brühl, C. and Crutzen, P. J., 1989: On the disproportionate role of tropospheric ozone as a filter against solar UV-B radiation, Geophys. Res. Lett. 16, 703–706.Google Scholar
  7. Buxton, G. V., Kilner, C., and Sellers, R. M., 1992: Pulse radiolysis of HOI and IO in aqueous solution, formation and characterization of I(II), Proc. Tihany Symp. Radiat. Chem. 6, 155–159.Google Scholar
  8. Carlier, P., Fresnet, P., Pashalidis, S., Tsetsi, M., Martinet, A., Lescoat, V., Dupont, B., Chebbi, A., and Girard, R., 1991: Study of the oxidation of acid precursors in marine atmosphere: Organosulphus compounds and aldehydes, in Air Pollution Research Report 35, 167–180.Google Scholar
  9. Carpenter, L. J., Sturges, W. T., Liss, P. S., Penkett, S. A., Alicke, B., Hebestreit, K., and Platt, U., 1998: Observations of alkyl iodides and bromides at Mace Head: Links to macroalgal emissions an IO formation, Paper presented at EGS XXIII General Assembly, Nice, France 20–24, 1998, Annales Geophysicae Supplement II 16, C718.Google Scholar
  10. Chambers, R. M., Heard, A. C., and Wayne, R. P., 1992: Inorganic gas-phase reactions of the nitrate radical: I2 + NO3 and I + NO3, J. Phys. Chem. 96, 3321–3331.Google Scholar
  11. Chameides, W. L. and Davis, D. D., 1980: Iodine: Its possible role in tropospheric photochemistry, J. Geophys. Res. 85, 7383–7398.Google Scholar
  12. Chatfield, R. B. and Crutzen, P. J., 1990: Are there interactions of iodine and sulfur species in marine air photochemistry? J. Geophys. Res. 95D, 22319–22341.Google Scholar
  13. Chinake, C. R. and Simoyi, R. H., 1996: Kinetics and mechanism of the complex bromate-iodine reaction, J. Phys. Chem. 100, 1643–1656.Google Scholar
  14. Cicerone, R. J., 1981: Halogens in the atmosphere, Rev. Geophys. Space Phys. 19, 123–139.Google Scholar
  15. Citri, O. and Epstein, I. R., 1988: Mechanistic study of a coupled chemical oscillator: The bromatechlorite-iodide reaction, J. Phys. Chem. 92, 1865–1871.Google Scholar
  16. Class, T. and Ballschmiter, K., 1988: Chemistry of organic traces in air, J. Atmos. Chem. 6, 35–46.Google Scholar
  17. Davis, D., Crawford, J., Liu, S., McKeen, S., Bandy, A., Thornton, D., Rowland, F. S., and Blake, D., 1996: Potential impact of iodine on tropospheric levels of ozone and other critical oxidants, J. Geophys. Res. 101D, 2135–2147.Google Scholar
  18. DeMore, W. B., Sander, S. P., Golden, D. M., Hampson, R. F., Kurylo, M. J., Howard, C. J., Ravishankara, A. R., Kolb, C. E., and Molina, M. J., 1997: Chemical kinetics and photochemical data for use in stratospheric modeling, JPL Publication 97-4, Jet Propulsion Laboratory, Pasadena, CA.Google Scholar
  19. Eigen, M. and Kustin, K., 1962: The kinetics of halogen hydrolysis, J. Am. Chem. Soc. 84, 1355–1361.Google Scholar
  20. Fenical, W., 1981: Natural halogenated organics, in E. K. Duutsma and R. Dawson (eds), Marine Organic Chemistry, Elsevier, New York, p. 375.Google Scholar
  21. Furrow, S., 1987: Reactions of iodine intermediates in iodate-hydrogen peroxide oscillators, J. Phys. Chem. 91, 2129–2135.Google Scholar
  22. Harwood, M. H., Burkholder, J. B., Hunter, M., Fox, R. W., and Ravishankara, A. R., 1997: Absorption cross sections and self-reaction kinetics of the IO radical, J. Phys. Chem. A 101, 853–863.Google Scholar
  23. Huie, R. E., Laszlo, B., Kurylo, M. J., Buben, S. N., Trofimova, E. M., Spassky, A. I., Messineva, N. A., Nevozhai, D., and Miziolek, A.W., 1995: The atmospheric chemistry of iodine monoxide, Halon Options Technical Working Conference, Albuquerque, NM, May 10.Google Scholar
  24. Jenkin, M. E., 1992 (Nov.): The photochemistry of iodine-containing compounds in the marine boundary layer, Tech. Report AEA-EE-0405, United Kingdom Atomic Energy Authority, Harwell Laboratory, Oxon, OX11 0RA, U.K.Google Scholar
  25. Jenkin, M. E., Cox, R. A. and Candeland, D. E., 1985: Photochemical aspects of tropospheric iodine behaviour, J. Atmos. Chem. 2, 359–375.Google Scholar
  26. Laszlo, B., Kurylo, M. J., and Huie, R. E., 1995: Absorption cross sections, kinetics of formation, and self-reaction of the IO radical produced via the laser photolysis of N2O/I2/N2 mixtures, J. Phys. Chem. 99, 11701–11707.Google Scholar
  27. Lengyel, I., Li, J., Kustin, K., and Epstein, I. R., 1996: Rate constants for reactions between iodine-and chlorine-containing species: A detailed mechanism of the chlorine dioxide/chlorite reaction, J. Am. Chem. Soc. 118, 3708–3719.Google Scholar
  28. Magi, L., Schweitzer, F., Pallares, C., Cherif, S., Mirabel, P., and George, C., 1997: Investigation of the uptake rate of ozone and methyl hydroperoxide by water surfaces, J. Phys. Chem. A 101, 4943–4949.Google Scholar
  29. Moyers, J. L. and Duce, R. A., 1972: Gaseous and particulate iodine in the atmosphere, J. Geophys. Res. 77, 5229–5238.Google Scholar
  30. Murphy, D. M., Thomson, D. S., and Middlebrook, A. M., 1997: Bromine, iodine and chlorine in single particles at Cape Grim, Geophys. Res. Lett. 24, 3197–3200.Google Scholar
  31. Nagy, J. C., Kumar, K., and Margerum, D. W., 1988: Non-metal redox kinetics: Oxidation of iodide by hypochlorous acid and by nitrogen trichloride measured by the pulsed-accelerated-flow method, Inorg. Chem. 27, 2773–2780.Google Scholar
  32. Olsen, R. J. and Epstein, I. R., 1991: Bifurcation analysis of chemical reaction mechanisms. I. Steady state bifurcation structure, J. Chem. Phys. 94, 3083–3095.Google Scholar
  33. Palmer, D. A., Ramette, R.W., and Mesmer, R. E., 1985: The hydrolysis of iodine: Equilibria at high temperatures, J. Nuclear Mat. 130, 280–286.Google Scholar
  34. Rahn, K. A., Borys, R. D., and Duce, R. A., 1976: Tropospheric halogen gases: Inorganic and organic components, Science 192, 549–550.Google Scholar
  35. Rancher, J. and Kritz, M. A., 1980: Diurnal fluctuations of Br and I in the tropical marine atmosphere, J. Geophys. Res. 85C, 5581–5587.Google Scholar
  36. Rasmussen, R. A., Khalil, M. A., Gunawarda, R., and Hoydt, S. D., 1982: Atmospheric methyl iodide (CH3I), J. Geophys. Res. 87, 3086–3090.Google Scholar
  37. Reifenhäuser, W. and Heumann, K. G., 1992: Determination of methyl iodide in the antarctic atmosphere and the south polar sea, Atmos. Environ. 26A, 2905–2912.Google Scholar
  38. Roehl, C. M., Burkholder, J. B., Moortgat, G. K., Ravishankara, A. R., and Crutzen, P. J., 1997: The temperature dependence of the uv absorption cross sections and the atmospheric implications of several alkyl iodides, J. Geophys. Res. 102D, 12819–12829.Google Scholar
  39. Sander, R. and Crutzen, P. J., 1996: Model study indicating halogen activation and ozone destruction in polluted air masses transported to the sea, J. Geophys. Res. 101D, 9121–9138.Google Scholar
  40. Schall, C. and Heumann, K. G., 1993: GC determination of volatile organoiodine and organobromine compounds in arctic seawater and air samples, Fres. J. Anal. Chem. 346, 717–722.Google Scholar
  41. Seery, D. J. and Britton, D., 1964: The continuous absorption spectra of chlorine, bromine, bromine chloride, iodine chloride, and iodine bromide, J. Phys. Chem. 68, 2263–2266.Google Scholar
  42. Singh, H. B., Salas, L. J., and Stiles, R. E., 1983: Methyl halides in and over the eastern pacific (40° N–32° S), J. Geophys. Res. 88, 3684–3690.Google Scholar
  43. Solomon, S., Garcia, R. R., and Ravishankara, A. R., 1994a: On the role of iodine in ozone depletion, J. Geophys. Res. 99D, 20491–20499.Google Scholar
  44. Solomon, S., Burkholder, J. B., Ravishankara, A. R., Garcia, R. R., 1994b: Ozone depletion and global warming potential of CF3I, J. Geophys. Res. 99D, 20929–20935.Google Scholar
  45. Spietz, P., Himmelmann, S., Gross, U., Orphal, J., and Burrows, J. P., 1998: Study of iodine oxides and iodine chemistry using flash photolysis and time resolved absorption spectroscopy, Paper presented at EGS XXIII General Assembly, Nice, France 20–24, 1998, Annales Geophysicae Supplement II 16, C722.Google Scholar
  46. Tellinghuisen, J., 1973: Resolution of the visible-infrared absorption spectrum of I2 into three contributing transitions, J. Chem. Phys. 58, 2821–2834.Google Scholar
  47. Troy, R. C. and Margerum, D. W., 1991: Non-metal redox kinetics: Hypobromite and hypobromous acid reactions with iodide and with sulfite and the hydrolysis of bromosulfate, Inorg. Chem. 30, 3538–3543.Google Scholar
  48. Troy, R. C., Kelley, M. D., Nagy, J. C., and Margerum, D.W., 1991: Non-metal redoxkinetics: Iodine monobromide reaction with iodide ion and the hydrolysis of IBr, Inorg. Chem. 30, 4838–4845.Google Scholar
  49. Truesdale, V., 1998: Kinetics of disproportionation of hypoiodous acid at high pH, with extrapolation to rainwater, J. Chem. Soc. Faraday Trans., in press.Google Scholar
  50. Vogt, R., Crutzen, P. J., and Sander, R., 1996: A mechanism for halogen release from sea-salt aerosol in the remote marine boundary layer, Nature 383, 327–330.Google Scholar
  51. Wagman, D. D., Evans, W. H., Parker, V. B., Schumm, R. H., Halow, I., Bailey, S. M., Churney, K. L., and Nuttall, R. L., 1982: The NBS tables of chemical thermodynamic properties; selected values for inorganic and C1 and C2 organic substances in SI units, J. Phys. Chem. Ref. Data 11, Suppl. 2.Google Scholar
  52. Wang, Y. L., Nagy, J. C., and Margerum, D.W., 1989: Kinetics of hydrolysis of iodine monochloride measured by the pulsed-accelerated-flow method, J. Am. Chem. Soc. 111, 7838–7844.Google Scholar
  53. Wimschneider, A. and Heumann, K. G., 1995: Iodine speciation in size fractionated atmospheric particles by isotope dilution mass spectrometry, Fresenius J. Anal. Chem. 353, 191–196.Google Scholar
  54. Yoshida, S. and Muramatsu, Y., 1995: Determination of organic, inorganic and particulate iodine in the coastal atmosphere of Japan, J. Radioanalytical and Nucl. Chem. 196, 295–302.Google Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Rainer Vogt
    • 1
  • Rolf Sander
    • 2
  • Roland von Glasow
    • 2
  • Paul J. Crutzen
    • 2
  1. 1.Ford Forschungszentrum Aachen GmbHAachenGermany
  2. 2.Max-Planck Institut für ChemieMainzGermany

Personalised recommendations