Eighth Symposium on Fire and Forest Meteorology


Real time forecast of tropospheric ozone and smoke aerosol produced from vegetation fires emissions over South America

Saulo R. Freitas, Centro de Previsao de Tempo e Estudos Climaticos / INPE, Cachoeira Paulista, SP, Brazil; and K. Longo, L. F. Rodrigues, M. Pirre, V. Marecal, M. Alonso, R. Mello, and R. Stockler

The high concentration of aerosol particles and trace gases observed in the Amazon and Central Brazilian atmosphere during the dry season is associated with intense anthropogenic biomass burning activity (vegetation fires). In addition to aerosol particles (PM), biomass burning produces water vapor and carbon dioxide, and is a major source of other compounds such as carbon monoxide (CO), volatile organic compounds, nitrogen oxides (NOx=NO+NO2), and organic halogen compounds. In the presence of abundant solar radiation and high concentrations of NOx, the oxidation of CO and hydrocarbons is followed by ozone (O3) formation. The high levels of O3 and PM induce several respiratory problems on the affect populated areas. PM has impact on weather modification by changing the energy budgets of the surface and troposphere, as well as the microphysical behavior of clouds, and consequently also their dynamics and precipitation efficiency. In this paper we describe a real time forecast of pyrogenic products over South America by using the Coupled Chemistry-Aerosol-Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CCATT-BRAMS). CCATT-BRAMS is an on-line transport model fully consistent with the simulated atmospheric dynamics and includes kinetic and photochemical reactions. The sub-grid transport parameterizations include diffusion in PBL, shallow and deep convection and plume rise for biomass burning emissions. The atmospheric model has a complex and state-of-art set of parameterizations to simulate surface-atmosphere exchanges, boundary layer development, cloud microphysics, radiative transfer, cumulus convection. Photolysis rates can either be used from LUT or calculated on-line using FAST-TUV which is fully coupled with the aerosol and microphysics modules. The system may be virtually configured with any desired chemical mechanism using a modified version of SPACK (Simplified Preprocessor for Atmospheric Chemical Kinetics). For initial and boundary conditions, the system is able to be forced by large scale atmospheric-chemistry models analysis using a Newtonian relaxation scheme. Currently the system is able to assimilate MOCAGE (Meteo-France model) chemistry fields. Emissions are prescribed through a pre-processor for anthropogenic, biogenic, biomass burning, etc, using a set of published methodologies or inventories. Fire emissions are updated on near real time and are spatially and temporally distributed according to the fire counts locations obtained by remote sensing (AVHRR, MODIS and GOES-12). We will present and discuss the main events of pollution associated to vegetation fires captured by this operational system for the next burning season (July-October, 2009) over South America.

extended abstract  Extended Abstract (892K)

wrf recording  Recorded presentation

Session 5A, Smoke from Wildland Fires I
Wednesday, 14 October 2009, 8:30 AM-10:00 AM, Lake McDonald/ Swift Current/ Hanging Gardens

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