Abstract. The concentration and speciation of iodine have been determined in wet and dry •)deposition at a coastal site over a 15-month period. Deposition fluxes in rain (2.7 txmol m -2 yrand aerosol (3.6-6.5 txmol m -2 yr -•) are the major routes for removal of iodine from the marine atmosphere onto the Earth's surface, with only a minor contribution from direct deposition of methyl iodide (0.003-0.17 txmol m -• yr-•). Iodate (IO•-) is often considered to be the only species of iodine that is permanently removed to the aerosol phase, and IO• may therefore be expected to be the dominant form of iodine in precipitation. However, iodide (I-) was found to constitute a significant fraction (5-100%) of iodine in both rain and aerosol. This implies that the rates of iodate formation and iodide volatilization (through reaction with hypohalous acids) are relatively slow. A third pool of aerosol iodine (nonvolatile organic compounds) may also contribute to removal of iodine from the atmosphere in dry or wet deposition. In this work we present the results of a long-term study of iodine deposition at a coastal site in southeast England. We have determined iodine concentrations in rain and aerosol samples and used these to calculate wet and dry deposition fluxes of iodine to the ground at the site. In addition, we also use gas-phase concentrations of methyl iodide, the longest-lived iodocarbon, to calculate the potential contribution to dry deposition of direct gas-to-land transfen This work follows on from the study of Campos et al. [1996], who reported that the annual emission budget of methyl iodide was in near balance with the deposition budget of iodine in rainfall in the southern North Sea region. The current data set is used to extend the iodine deposition budget, by inclusion of dry deposition, which was neglected in the earlier work. In addition, by examining the speciation of iodine in aerosol and rain we consider the influence of meteorology on the atmospheric processing of iodine in aerosol.