Séminaire
The cycling of reactive organic carbon (ROC) is central to tropospheric chemistry, driving the oxidative chemistry of the atmosphere, affecting the hydroxyl radical concentrations, and methane lifetime. In this presentation, the global tropospheric ROC budget as simulated with the GEOS-Chem model is presented. This budget is an expansion of the standard simulation, that includes new emissions and gas-phase chemistry, an extension of dry and wet removal mechanism, and a mass tracking of all ROC species to achieve carbon closure. The presentation will then focus on the wet deposition of dissolved organic carbon (DOC), the largest physical removal pathway of ROC. No previous global assessment of the composition and global distribution of DOC has been presented to date. Here, we investigate the simulated DOC composition, spatial distribution, and evolution in the global atmosphere, and compare these with historical DOC measurements.