Determinação e modelagem da taxa de consumo de biomassa queimada

Abstract

O presente trabalho avalia o emprego da energia radiativa do fogo (ERF) para estimar as emissões de material particulado com diâmetro menor que 2,5µm (PM2,5µm), a partir da obtenção do coeficiente multiplicativo, que relaciona o consumo de biomassa com a ERF liberada. Para isto, foram utilizados dados provenientes dos produtos do MODIS (Moderate Resolution Imaging Spectroradiometer) e do produto derivado do satélite GOES (Geostationary Operational Environmental Satellite), para calcular o total de aerossóis emitidos para a atmosfera. O CCATT-BRAMS (Coupled Chemistry-Aerosol-Tracer Transport model coupled to Brazilian Regional Atmospheric Modelling System) foi utilizado para estimar a concentração de PM2,5µm provenientes da queima de biomassa. Estes dados foram comparados com os dados de campo obtidos nos experimentos do LBA (Large Scale Biosphere-Atmosphere) SMOCC (Smoke, Aerosols, Clouds, rainfall, and Climate) e RaCCI (Radiation, Cloud, and Climate Interactions). A estimativa da emissão de PM2,5µm (µg.m-3) apresentou uma correlação com os dados do SMOCC/RaCCI superiores a 92%. Ainda, constatou-se que o consumo máximo diário pode exceder 5 Tg (milhões de toneladas), com uma média diária de 2,1 Tg. O método resultante das análises de laboratório permitiu estimar a biomassa consumida em 0,28 ± 0,01 Pg (10(15) g) para a América do Sul, entre Julho e Novembro de 2002.The present study evaluates the use of fire radiative energy (FRE) to estimate the emissions of particulate matter with diameter less than 2.5 μm (PM2,5µm) from the multiplicative coefficient relating the biomass consumption with the released FRE. The MODIS (Moderate Resolution Imaging Spectroradiometer) and GOES (Geostationary Operational Environmental Satellite) products were utilized to calculate the total amount of aerosol emitted to the atmosphere. The CCATT-BRAMS (Coupled Chemistry-Aerosol-Tracer Transport model coupled to Brazilian Regional Atmospheric Modelling System) model was used to estimate the PM2,5µm concentration generated by biomass burning. The model results were compared with data obtained from the LBA (Large Scale Biosphere-Atmosphere), SMOCC (Smoke, Aerosols, Clouds, rainfall, and Climate) and RaCCI (Radiation, Cloud, and Climate Interactions) field experiments. The estimated PM2,5µm emission has a correlation with the SMOCC/RaCCI data greater than 92%. It was also verified that the maximum daily consumption can exceed 5 Tg (5,000,000 ton.), with a daily average of 2.1 Tg. The resulting method from laboratory analysis estimated a total of 0.28 ± 0.01 Pg (10(15) g) biomass consumed from July to November 2002 in South America.