Development of a Wildland Fire Smoke Marker Emissions Map for the Contiguous United States

Several chemical species, including levoglucosan, mannosan, galactosan and K+, are characteristic components of smoke produced from biomass combustion. In the Fire Lab at Missoula Experiment (FLAME), over 30 different wildland fuels were burned, and the smoke produced was analyzed for physical, chemical and optical properties. High volume filter samples were collected and analyzed for sugars and anhydrosugars using high performance anion exchange chromatography with pulsed amperometric detection. Total carbon concentrations were analyzed on a Sunset organic/elemental carbon analyzer. Major ion concentrations were quantified using ion chromatography. Several patterns emerged from statistical analysis of the smoke marker species, particularly that different vegetation classes (e.g. leaves, needles, branches and grasses) produced different marker to carbon ratios. Because vegetation classes are spatially distributed throughout the country, this information can be translated into geographic information. For example, wildfires in the softwood forests of the Western United States (U.S.) might burn mostly branches and needles, while prescribed fires of the plains in the Midwest might burn mostly grasses. Using a wildland fuel type map from the United States Forest Service, several geographic biomes have been identified including softwood forests, hardwood forests, scrub brush, grasslands, and floral shrub lands. Source profiles for smoke markers based on the measurements made during FLAME were assigned to each vegetation class. Using the fuel type map and fuel specific source profiles, a 12 km gridded map of fire emission smoke profiles was created for the U.S. Each cell of the grid has been assigned a percentage of each vegetation class likely to be consumed in an average fire and the source profile for this mix of vegetation consumed. The end product is a map of smoke marker source profiles. Provided the location of the fires impacting a receptor can be estimated, these geographically distributed source profiles can be used in receptor models to better apportion primary particulate carbonaceous material to wild and prescribed fire.