Simulating the impact of wild fire emissions on regional chemistry and meteorology using a coupled atmosphere-fire-chemistry model WRF-SFIRE-Chem
In this study, we demonstrate the use of a coupled atmosphere-fire-chemistry model WRF- SFIRE-Chem to evaluate the impact of wildland fires on regional chemistry and meteorology. WRF-SFIRE is a two-way coupled fire atmosphere model that simulates the fire spread based on the local meteorological conditions, taking into account the feedback between the fire and the atmosphere. Included in WRF-SFIRE is a fuel moisture model that assimilates RAWS fuel moisture data and accounts for the effects of local meteorology simulated by WRF on the fuel flammability. The fire model is also coupled with WRF-Chem so that chemistry, transport, and radiation-cloud-feedbacks of gases and particles emitted from the fire are taken into account. Emissions rates are based on fuel consumption calculated by the fire model and emission factors from FINN. Emissions are inserted into the lowest atmospheric layer and transported vertically according to updrafts associated with the fire heat flux. The use of WRF- SFIRE-Chem is demonstrated for two very large Santa Ana fires in southern California in 2007.