The biomass-burning aerosols (BBA) released from fires are important to global climate because of their roles as solar shortwave absorbers, cloud condensation nuclei (CCN), and ice-nucleating particles (INP). The radiative effect of BBAs, in terms of magnitude and even the sign, is very sensitive to their vertical distributions. In this study, we implement an interactive fire plume-rise model (Freitas et al. 2007) to replace the default prescribed vertical profiles of monthly biomass burning (BB) aerosol emissions in the DOE Energy Exascale Earth System Model (E3SM). The vertical distribution of BB aerosol emissions for each grid is calculated as a function of 1) ambient thermodynamic conditions predicted by the host E3SM; and 2) distributions of fire sizes and heat fluxes that are based on MODIS observations. In addition, we introduce the diurnal cycle of BB aerosol emissions based on Li et al. (2019). Modeled plume injection heights are validated against the wildfire plume height product retrieved from the Multi-angle Imaging SpectroRadiometer (MISR) observations, and modeled biomass burning aerosols vertical profiles are compared against the in-situ aircraft observations from the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAM) field campaign. The comparison results indicate that by including the interactive fire plume-rise model and diurnal cycle of BB aerosol emissions, both modeled plume heights and BBA vertical distributions are significantly improved.
We also conduct 10-year climatology simulations with the plume-rise model, in comparison with the default simulation. The result shows that the inclusion of the interactive fire plume-rise model can cause a significant radiative effect of 0.12 W m-2 at top of atmosphere (TOA). The zonal mean radiative effect in high latitude can be as strong as 1~1.6 W m-2 at TOA.