Assessing uncertain iodine multiphase chemistry: Ozone layer health, Oxidants and Methane trends

Iodine is a micronutrient and atmospheric trace element that rivals isoprene in terms of atmospheric impacts on ozone, oxidation capacity, and particle formation. Sources to the atmosphere have tripled in recent decades due to anthropogenic enhancements of abiotic ocean emissions triggered by the deposition of pollution ozone and thinning sea ice. This presentation reviews the historical perspective on iodine in WMO ozone assessment reports, and presents first simultaneous measurements of organic VSLS, inorganic iodine gas, and particulate iodine aboard research aircraft in the lower stratosphere (TI3GER field campaign). The multiphase chemistry during convective transport remains poorly understood, and is assessed using laboratory experiments, field observations of vertical profiles up to 15km, and atmospheric modeling.