Articles | Volume 9, issue 8
Atmos. Chem. Phys., 9, 2843–2861, 2009
Atmos. Chem. Phys., 9, 2843–2861, 2009

  28 Apr 2009

28 Apr 2009

The Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS) – Part 1: Model description and evaluation

S. R. Freitas1, K. M. Longo1,*, M. A. F. Silva Dias1,2, R. Chatfield3, P. Silva Dias2, P. Artaxo4, M. O. Andreae5, G. Grell6, L. F. Rodrigues1, A. Fazenda1,7, and J. Panetta1 S. R. Freitas et al.
  • 1Center for Weather Forecasts and Climate Studies (CPTEC), INPE, Cachoeira Paulista, Brazil
  • 2Department of Atmospheric Sciences, University of São Paulo, Brazil
  • 3NASA Ames Research Center, Moffett Field, USA
  • 4Institute of Physics, University of São Paulo, Brazil
  • 5Max Planck Institute for Chemistry, Mainz, Germany
  • 6Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado/NOAA Research-Forecast Systems Laboratory, Boulder, CO, USA
  • 7Department of Computing Science, University of Taubaté, São Paulo, Brazil
  • *now at: Center for Space and Atmospheric Sciences, INPE, São José dos Campos, Brazil

Abstract. We introduce the Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CATT-BRAMS). CATT-BRAMS is an on-line transport model fully consistent with the simulated atmospheric dynamics. Emission sources from biomass burning and urban-industrial-vehicular activities for trace gases and from biomass burning aerosol particles are obtained from several published datasets and remote sensing information. The tracer and aerosol mass concentration prognostics include the effects of sub-grid scale turbulence in the planetary boundary layer, convective transport by shallow and deep moist convection, wet and dry deposition, and plume rise associated with vegetation fires in addition to the grid scale transport. The radiation parameterization takes into account the interaction between the simulated biomass burning aerosol particles and short and long wave radiation. The atmospheric model BRAMS is based on the Regional Atmospheric Modeling System (RAMS), with several improvements associated with cumulus convection representation, soil moisture initialization and surface scheme tuned for the tropics, among others. In this paper the CATT-BRAMS model is used to simulate carbon monoxide and particulate material (PM2.5) surface fluxes and atmospheric transport during the 2002 LBA field campaigns, conducted during the transition from the dry to wet season in the southwest Amazon Basin. Model evaluation is addressed with comparisons between model results and near surface, radiosondes and airborne measurements performed during the field campaign, as well as remote sensing derived products. We show the matching of emissions strengths to observed carbon monoxide in the LBA campaign. A relatively good comparison to the MOPITT data, in spite of the fact that MOPITT a priori assumptions imply several difficulties, is also obtained.

Final-revised paper