Fig. 5.

Fractional contributions of wildfire emissions to BaP air concentrations. a, Fractional contribution (%) of wildfire emissions to BaP air concentrations averaged over the Arctic from 2001 to 2020. b–e, Annual variation of the contribution of wildfire emissions to BaP concentrations from 2001 to 2020 in the Arctic (b), the Asian Arctic (c), the North American Arctic (d), and the European Arctic (e). The fractional contribution is defined as (C_wildfire/C_base) × 100, where C_wildfire and C_base are BaP air concentrations simulated by the CanMETOP model subject to wildfire and total BaP emissions.