ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-9-823-2009 The time dependence of molecular iodine emission from <i>Laminaria digitata</i> Dixneuf S. 1 Ruth A. A. 1 Vaughan S. 1 Varma R. M. 1 Orphal J. 1 2 Department of Physics, University College Cork, Cork, Ireland Laboratoire Interuniversitaire des Systèmes Atmosphériques, Université de Paris-Est, Créteil, France 02 02 2009 9 3 823 829 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/9/823/2009/acp-9-823-2009.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/9/823/2009/acp-9-823-2009.pdf

We present the first in situ detection of molecular iodine emitted from the brown macroalga <i>Laminaria digitata</i> under natural stress conditions. We show that the release of I<sub>2</sub> occurs in short, strong bursts with a complex time signature. The new data indicate that algal control of I<sub>2</sub> release in the form of an oscillatory time-dependence may be based on a nonlinear autocatalytic reaction scheme which is closely linked to the production of H<sub>2</sub>O<sub>2</sub>.

 References Amat, M. A. and Srivastava, L. M.: Translocation of iodine in Laminaria-saccharina (phaeophyta), J. Phycol., 21, 330–333, 1985. Bale, C. S. E., Ingham, T., Commane, R., Heard, D. E., and Bloss, W. J.: Novel measurements of atmospheric iodine species by resonance fluorescence, J. Atmos. Chem., 60, 51–70, 2008. Bitter, M., Ball, S. M., Povey, I. M., and Jones, R. L.: A broadband cavity ringdown spectrometer for in-situ measurements of atmospheric trace gases, Atmos. Chem. Phys., 5, 2547–2560, 2005. Bolton, J. J. and Lüning, K.: Optimal growth and maximal survival temperatures of atlantic \textitLaminaria species (Phaeophyta) in culture, Mar. Biol., 66, 89–94, 1982. Bray, W. C. and Liebhafsky, H. A.: Reactions Involving Hydrogen Peroxide, Iodine and Iodate Ion. I. Introduction, J. Phys. Chem., 53, 38–48, 1931. Briggs, T. S. and Rauscher, W. C.: Oscillating iodine clock, J. Chem. Educ., 50, 496–496, 1973. Carpenter, L. J., Malin, G., Liss, P. S., and Küpper, F. C.: Novel biogenic iodine-containing trihalomethanes and other short-lived halocarbons in the coastal East Atlantic, Global Biogeochem. Cy., 12, 1191–1204, 2000. Carpenter, L. J.: Iodine in the marine boundary layer, Chem. Rev., 103, 4953–4962, 2003. Colin, C., Leblanc, C., Wagner, E., Delage, L., Leize-Wagner, E., Van Dorsselaer, A., Kloareg, B., and Potin, P.: The brown algal kelp Laminaria digitata features distinct bromoperoxidase and iodoperoxidase activities, J. Biol. Chem., 278, 23 545–23 352, 2003. Fiedler, S. E., Hese, A., and Ruth, A. A.: Incoherent broad-band cavity-enhanced absorption spectroscopy, Chem. Phys. Lett., 371, 284–294, 2003. Furrow, S. D. and Noyes, R. M.: The oscillatory Briggs-Rauscher reaction. 1. Examination of subsystems, J. Am. Chem. Soc., 104, 38–42, 1982. Ar Gall, E., Küpper, F. C., and Kloareg, B.: A survey of iodine content in Laminaria digitata, Bot. Mar., 47, 30–37, 2004 (and references therein). Gherman, T., Venables, D. S., Vaughan, S., Orphal, J., and Ruth, A. A.: Incoherent broadband cavity-enhanced absorption spectroscopy in the near-ultraviolet: Application to HONO and NO<sub>2</sub>, Environ Sci. Technol., 42, 890–895, 2008. von Glasow, R.: Seaweed, iodine, new particles and atmospheric chemistry – the current state of play, Environ. Chem., 2, 243–244, 2005. Küpper, F. C., Schweigert, N., Ar Gall, E., Legendre, J.-M., Vilter, H., and Kloareg, B.: Iodine uptake in Laminariales involves extracellular, haloperoxidase-mediated oxidation of iodide, Planta, 207, 163–171, 1998. Küpper, F. C., Kloareg, B., Guern, J., and Potin, P.: Oligoguluronates elicit an oxidative burst in the brown algal kelp Laminaria digitata, Plant Physiol., 125, 278–291, 2001. Küpper, F. D., Müller, D. G., Peters, A. F., Kloareg, B., and Potin, P.: Oligoalginate recognition and oxidative burst play a key role in natural and induced resistance of sporophytes of Laminariales, J. Chem. Ecol., 28, 2057–2081, 2002. Küpper, F. D., Carpenter, L. C., McFiggans, G. B., Palmer, C. J., Waite T. J., Boneberg, E.-M., Woitsch, S., Weiller, M., Abela, R., Grolimund, D., Potin, P., Butler, A., Luther III, G. W., Kroneck, P. M. H., Meyer-Klaucke, W., and Feiter, M. C.: Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry, P. Natl. Acad. Sci. USA, 105, 6954–6958, 2008. Laturnus, F., Svensson, T., Wiencke, C., and Öberg, G.: Ultraviolet radiation affects emission of ozone-depleting substances by marine macroalgae: results from a laboratory incubation study, Environ. Sci. Technol., 38, 6605–6609, 2004. Leblanc, C., Colin, C., Cosse, A., Delage, L., La Barre, S., Morin, P., Fiévet, B., Voiseux, C., Ambroise, Y., Verhaeghe, E., Amouroux, D., Donard, O., Tessier, E., and Potin, P.: Iodine transfers in the coastal marine environment: the~key role of brown algae and of their vanadium-dependent haloperoxidases, Biochimie, 88, 1773–1785, 2006. Lewis, J. R.: The Ecology of Rocky Shores, The English Universities Press, London, 1964. McFiggans, G., Coe, H., Burgess, R., Allan, J., Cubison, M., Alfarra, M. R., Saunders, R., Saiz-Lopez, A., Plane, J. M. C., Wevill, D. J., Carpenter, L. J., Rickard, A. R., and Monks, P. S.: Direct evidence for coastal iodine particles from Laminaria macroalgae – linkage to emissions of molecular iodine, Atmos. Chem. Phys., 4, 701–713, 2004. Noyes, R. M. and Furrow, S. D.: The oscillatory Briggs-Rauscher reaction. 3. A skeleton mechanism for oscillations, J. Am. Chem. Soc., 104, 45–48, 1982. O'Dowd, C. D., Jimenez, J. L., Bahreini, R., Flagan, R. C., Seinfeld, J. H., Hameri, K., Pirjola, L., Kulmala, M., Jennings, S. G., and Hoffmann, T.: Marine aerosol formation from biogenic iodine emissions, Nature, 417, 632–636, 2002. O'Dowd, C. D. and Hoffmann, T.: Coastal new particle formation: A review of the current state-of-the-art, Environ. Chem., 2, 245–255, 2005. Press, W. H., Flannery, T. S., and Vetterling W. T.: Numerical Recipes: The Art of Scientific Computing, Cambridge University Press, Cambridge, p 51 and p 670, 1986. Palmer, C. J., Anders, T. L., Carpenter, L. J., Küpper, F. C., and McFiggans, G. B.: Iodine and halocarbon response of Laminaria digitata to oxidative stress and links to atmospheric new particle production, Environ. Chem., 2, 282–290, 2005. Ruth, A. A., Orphal, J., and Fiedler, S. E.: Cavity enhanced Fourier transform absorption spectroscopy using an incoherent broadband light source, Appl. Optics, 46, 3611–3616, 2007. Saiz-Lopez, A. and Plane, J. M. C.: Novel iodine chemistry in the marine boundary layer, Geophys. Res. Lett., 31, L04112, doi:10.1029/2003GL019215, 2004a. Saiz-Lopez, A., Saunders, R. W., Joseph, D. M., Ashworth, S. H., and Plane, J. M. C.: Absolute absorption cross-section and photolysis rate of I<sub>2</sub>, Atmos. Chem. Phys., 4, 1443–1450, 2004b. Saiz-Lopez, A., Plane, J. M. C., McFiggans, G., Williams, P. I., Ball, S. M., Bitter, M., Jones, R. L., Hongwei, C., and Hoffmann, T.: Modelling molecular iodine emissions in a coastal marine environment: the link to new particle formation, Atmos. Chem. Phys., 6, 883–895, 2006. Schmitz, G.: The oxidation of iodine to iodate by hydrogen peroxide, Phys. Chem. Chem. Phys., 3, 4741–4746, 2001. Valent, I., Adamèíková, L., and Å evèík, P.: Simulations of the iodine interphase transport effect on the oscillating Bray-Liebhafsky reaction, J. Phys. Chem. A, 102, 7576–7579, 1998. Vaughan, S., Gherman, T., Ruth, A. A., and Orphal, J.: Incoherent broadband cavity-enhanced absorption spectroscopy of the marine boundary layer species I<sub>2</sub>, IO and OIO, Phys. Chem. Chem. Phys., 10, 4471–4477, 2008. Venables, D. S., Gherman, T., Orphal, J., Wenger, J., and Ruth A. A.: High sensitivity in situ monitoring of NO<sub>3</sub> in an atmospheric simulation chamber using incoherent broadband cavity-enhanced absorption spectroscopy, Environ. Sci. Technol., 40, 6758–6763, 2006. Verhaeghe, E. F., Fraysse, A., Guerquin-Kern, J.-L., Wu, T.-D., Devès, G., Mioskowski, C., Leblanc, C., Ortega, R., Ambroise, Y., and Potin, P.: Microchemical imaging of iodine distribution in the brown alga \textitLaminaria digitata suggests a new mechanism for its accumulation, J. Biol. Inorg. Chem., 13, 257–269, 2008.