The impact of climate change on area burned In Alberta's Boreal Forest

Eight years of fire weather data from sixteen representative weather stations within the boreal forest natural region of Alberta were used to compile separate data sets for low, moderate, high, very high and extreme fire weather (FWI). Averages of the 44th to 56th percentiles were then calculated for each FWI class data set for fine fuel moisture code (FFMC), duff moisture code (DMC), and drought code (DC). Predominant wind direction and average temperature, RH and wind speed were also obtained for each FWI class data set. These reference weather streams were adjusted to create daily weather streams for input into Prometheus – the Canadian Wildland Fire Growth Model. Prometheus uses a diurnal routine to convert the daily weather stream into a 24 hour weather stream which is required for fire growth simulation. Similar fire weather analysis were completed using RCM output for northern Alberta (174 grid cells) to generate FWI class data sets (temp, RH, WS, FFMC, DMC and DC) for 1x, 2x and 3x CO2 scenarios. The relative differences between the RCM scenario outputs were then used to adjust the reference weather streams for northern Alberta. Area burned was calculated for each fire weather class and climate change scenario by repetitively replaying a high fire load day (21 fire arrivals) that occurred on July 20, 1999 in the Lac La Biche Forest. The area burned estimates were weighted based on the frequency of occurrence of fire starts by FWI class, and then normalized to derive relative area burned estimates for each climate change scenario.