Boreal forest fires burn less intensely in Russia than in North America

Around 5 - 20 million hectares of boreal forest burns annually, mainly in Russia and North America. However, there are reports of significant differences in predominant fire type between these regions, which may have major implications for overall emissions of carbon, gases and aerosols. We examine boreal forest fire intensities via MODIS observations of fire radiative energy release rate. Results support the contention of a consistent difference in fire intensity and mean fuel consumption in Russia and North America, due to differences in dominant fire type. North American fires have higher mean intensities, increasing in proportion to percentage tree cover, characteristics indicating likely crown fire dominance. Russian fires have lower mean intensities, independent of percentage tree cover, characteristics more indicative of surface fire activity. Per unit area burnt, the results suggest Russian fires may burn less fuel and emit fewer products to the atmosphere than do those in North America.