7A.5 Effects of aerosol representation complexity on air quality and weather forecasting skill over South America

Bela, Megan, and Georg Grell, National Oceanic and Atmospheric Administration/Earth Systems Research Laboratory (NOAA/ESRL), Saulo Freitas, National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC), Ravan Ahmadov, NOAA/ESRL, Gabriel Pereira, NASA/GSFC and Federal University of São João del-Rei, KaYee Wong, Li Zhang, and Mariusz Pagowski, NOAA/ESRL

WRF-Chem simulations of regional smoke observed during the 2012 South American Biomass Burning Analysis (SAMBBA) campaign are conducted to determine whether more complex aerosol schemes improve air quality and meteorological forecasting skill over South America. The WRF-Chem representations of aerosol range in complexity from climatology (meteorology only) to aerosol-aware Thompson microphysics (primary smoke aerosol emissions but no gas or aqueous chemistry) to RACM-MADE-VBS-AQCHEM, state-of-the-art gas/aqueous/aerosol chemistry that provides cloud condensation nuclei distributions to the cloud microphysics. The simulations are evaluated against ground-based and SAMBBA aircraft gas and aerosol, cloud, and meteorology observations, as well as MODIS and AERONET AOD, TRMM precipitation, and radiosoundings. The SAMBBA flights spanned the dry-to-wet transition season and thus provide useful case studies for examining aerosol-radiation and aerosol-cloud feedbacks. Simulations using an aerosol-aware cumulus parameterization are compared with high resolution simulations and used to quantify regional and seasonal scale aerosol effects.