Laboratory investigation of fire radiative energy and smoke aerosol emissions

Fuel biomass samples from southern Africa and the United States were burned in a laboratory combustion chamber while measuring the biomass consumption rate, the fire radiative energy (FRE) release rate (R-fre), and the smoke concentrations of carbon monoxide (CO), carbon dioxide (CO2), and particulate matter (PM). The PM mass emission rate (R-PM) was quantified from aerosol optical thickness (AOT) derived from smoke extinction measurements using a custom-made laser transmissometer. The R-PM and Rfre time series for each fire were integrated to total PM mass and FRE, respectively, the ratio of which represents its FRE-based PM emission coefficient (C-e(PM)). A strong correlation (r(2) = 0.82) was found between the total FRE and total PM mass, from which an average C-e(PM) value of 0.03 kg MJ(-1) was calculated. This value agrees with those derived similarly from satellite-borne measurements of R-fre and AOT acquired over large-scale wildfires.