Emissions from burning of relevant boreal forest materials: A PMF approach for combustion phase separation and MAC determination

An increase in wildfire prevalence in Canada1 endangers 25 % of the world’s boreal forest. Emissions from these wildfires are known to impact both climate and health, necessitating thorough characterization to better evaluate these impacts. To this end, a consortium of academic researchers and government scientists has come together under Biomass Burning Canada (BBCan) to conduct controlled combustion experiments for extensive chemical and optical properties characterization of the smoke emissions.
In these experiments, a bottom-up approach is taken to characterize various fuels found in the boreal forest such as peat (wet and dry), mulch (wet and dry), grass, and surface material (branches and twigs), to assess fuel specific emission characteristics and properties. Here we present an application of Positive Matrix Factorization (PMF) on SP-AMS aerosol composition data to elucidate the chemical signatures of particles during flaming and smouldering phases of peat and mulch combustion. To better determine climate impacts, the PMF results are combined with aethalometer data, a filter-based optical property measurement technique, to determine the mass absorption cross-sections (MAC) of the flaming and smouldering particles through multi-linear regression. For fuels where the speed of combustion limits temporal resolution, such as grass and surface material, an overall MAC is determined instead.
References

(1) Wang, X.; Thompson, D. K.; Marshall, G. A.; Tymstra, C.; Carr, R.; Flannigan, M. D. Increasing Frequency of Extreme Fire Weather in Canada with Climate Change. Climatic Change 2015, 130 (4), 573–586.