Using Aerosol and Chemistry Modules of Different Complexity in a Global Model to Look at the Impact of Aerosol Predictions on Numerical Weather Prediction

The global Flow-following finite-volume Icosahedra Model (FIM), which was developed in the Global Systems Division of NOAA/ESRL, has been coupled online with aerosol and gas-phase chemistry schemes (FIM-Chem) of different complexity.  The simplest aerosol modules are from the GOCART model that includes only simplified sulfur chemistry. A more complex photochemical gas-phase mechanism (such as used by ECMWF) was included to determine the impact of the additional complexity on the aerosols simulations. Further sophistication within the aerosol modules includes secondary organic aerosols. Within the aerosol and chemistry modules FIM-Chem handles wet and dry deposition, simple aqueous phase chemistry, biogenic emissions, biomass burning, dust and sea-salt. Here we will compare more sophisticated chemistry and aerosol package packages with the simpler package (GOCART) with a focus on impact on numerical weather prediction. ESRL produces experimental 7 day forecasts twice a day in real-time on 60km global resolution ( http://fim.noaa.gov/FIM/Welcome.cgi?dsKey=fimx_jet).