Estimated total emissions of trace gases from the Canberra wildfires of 2003: a new method using satellite measurements of aerosol optical depth and the MOZART chemical transport model

Abstract

Abstract. In this paper we describe a new method for estimating trace gas emissions from large vegetation fires using measurements of aerosol optical depth from the MODIS instruments onboard NASA's Terra and Aqua satellites, combined with the atmospheric chemical transport model MOZART. The model allows for an estimate of double counting of enhanced levels of aerosol optical depth in consecutive satellite overpasses. Using this method we infer an estimated total emission of 10±3 Tg of carbon monoxide from the Canberra fires of 2003. Emissions estimates for several other trace gases are also given. An assessment of the uncertainties in the new method is made and we show that our estimate agrees (within expected uncertainties) with estimates made using current conventional methods of multiplying together factors for the area burned, fuel load, the combustion efficiency and the emission factor for carbon monoxide. The new method for estimating emissions from large vegetation fires described in this paper has some significant uncertainties, but these are mainly quantifiable and largely independent of the uncertainties inherent in conventional techniques. Thus we conclude that the new method is a useful additional tool for characterising emissions from vegetation fires.

Trace gas emissions from savanna fires in northern Australia

“…In conclusion, the relatively strong correlation that exists between CO total columns and AOD in the dry season means that in theory it would be possible to use satellite measurements of AOD to estimate emissions from Australian savanna fires in a similar manner to that done for Australian forest fires in the work of Paton‐Walsh et al [2010]. However, the complicating effects of the buildup of aged smoke and the influence of transported smoke into the region make interpretation of the measurements significantly harder than for southeast Australian forest fires.…”

“…Strong correlations between trace gas column amounts and aerosol optical depth (AOD) have been observed previously through smoke plumes from south east Australian forest fires [ Paton‐Walsh et al , 2004, 2005, 2008] and used in conjunction with atmospheric dispersion modeling to make a total emissions estimate for a major fire event [ Paton‐Walsh et al , 2010]. Similarly, strong correlations have been observed between AOD and CO measurements from NASA's Terra satellite in biomass burning plumes over South America and Africa [ Edwards et al , 2006a].…”

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

“…Wooster et al, 2003Wooster et al, , 2005 or aerosol optical depth (e.g. Paton-Walsh et al, 2010a, 2012. In order to characterise the major emissions from vegetation fires, all these methods require knowledge of the emission factors for the relevant ecosystem.…”

Impact of the New South Wales fires during October 2013 on regional air quality in eastern Australia

“…Less well known is that the 10 death toll from air quality impacts may exceed those killed directly in the fires (Johnston et al, 2011(Johnston et al, , 2013. Fires are * Corresponding author Email address: geraldine.rea@lmd.polytechnique.fr (Géraldine Rea) more commons in the north , where the tropical savanna is affected every year by fires, but the southeast, where there is the majority of the population (7,3 millions in-15 habitants in New South Wales), is also regularly affected by extreme fire events (Gupta et al, 2007;Paton-Walsh et al, 2010;Dirksen et al, 2009). During the bushfire seasons (October-February) of 1993-94 and 2002-03 for instance, more than 2,200,000 ha were burned.…”

“…Modelling fires in Australia are often conducted with global CTMs, i.e at low resolution, and for long range transport (Dirksen et al, 2009) or emissions calculation purposes (Paton-Walsh et al, 2010). In an epidemiological 60 study, Johnston et al (2012) use a global CTM associated with satellite observations to estimate global PM exposure to smoke from fires.…”