New emission factors for Australian vegetation fires measured using open-path Fourier transform infrared spectroscopy – Part 1: Methods and Australian temperate forest fires

摘要

Biomass burning releases trace gases and aerosol particles thatsignificantly affect the composition and chemistry of the atmosphere.Australia contributes approximately 8% of gross global carbonemissions from biomass burning, yet there are few previous measurements ofemissions from Australian forest fires available in the literature. Thispaper describes the results of field measurements of trace gases emittedduring hazard reduction burns in Australian temperate forests usingopen-path Fourier transform infrared spectroscopy. In a companion paper,similar techniques are used to characterise the emissions from hazardreduction burns in the savanna regions of the Northern Territory. Details ofthe experimental methods are explained, including both the measurementset-up and the analysis techniques employed. The advantages anddisadvantages of different ways to estimate whole-fire emission factors arediscussed and a measurement uncertainty budget is developed.Emission factors for Australian temperate forest fires are measured locallyfor the first time for many trace gases. Where ecosystem-relevant data arerequired, we recommend the following emission factors for Australiantemperate forest fires (in grams of gas emitted per kilogram of dry fuelburned) which are our mean measured values: 1620 ± 160 g kg ofcarbon dioxide; 120 ± 20 g kg of carbon monoxide; 3.6 ± 1.1 g kgof methane; 1.3 ± 0.3 g kg of ethylene; 1.7 ± 0.4 g kg of formaldehyde; 2.4 ± 1.2 g kg ofmethanol; 3.8 ± 1.3 g kg of acetic acid; 0.4 ± 0.2 g kg of formic acid; 1.6 ± 0.6 g kg ofammonia; 0.15 ± 0.09 g kg of nitrous oxide and 0.5 ± 0.2 g kg ofethane.