A43M-08:
IODINE'S IMPACT ON TROPOSPHERIC OXIDANTS; A GLOBAL CTM EVALUATION WITHIN GEOS-CHEM
Thursday, 18 December 2014: 3:25 PM
Tomas Sherwen1, Lucy Carpenter1, Mathew J Evans1, Rainer M Volkamer2, Barbara K Dix2 and Alfonso Saiz-Lopez3, (1)University of York, York, United Kingdom, (2)Univ. of Colorado, Boulder, Boulder, CO, United States, (3)Spanish National Research Council, Zaragoza, Spain
Abstract:
Global chemistry and climate models tend to not include tropospheric halogens. However, their impact on ozone and other oxidants, predominantly through bromine and iodine chemistry, have been shown through previous process studies. We discus here additions to the GEOS-Chem model, which already includes bromine chemistry, to provide an iodine simulation. We include oceanic emissions of iodinated hydrocarbon and inorganic iodine fluxes (HOI and I2) tied to both O3 deposition and sea surface iodide concentration. The chemistry scheme is based on the available kinetic literature and we include both dry and wet deposition. We evaluate the model against a range of observational constraints including IO measurements. We will discuss the global budget of iodine and its impact on ozone and oxidizing capacity and the impact of emission and kinetic uncertainties on these conclusions.
