Interactions between Thunderstorms, Chemistry, and Aerosols for a Severe Storm Ingesting an Elevated Wildfire Smoke Plume

The Deep Convective Clouds and Chemistry (DC3) field experiment made observations of a unique case of severe convection that ingested the High Park smoke plume at a 7 km altitude. Here, we use two cloud-resolving models, the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and the Colorado State University Regional Atmospheric Modeling System (RAMS), to estimate the impact of smoke aerosols on storm structure, dynamics, lightning, and subsequent chemistry. We first evaluate how well each of the models represents the meteorology by comparing radar reflectivity, outgoing long-wave radiation, and other thermodynamic variables with observations.

An initial set of simulations is conducted in which tracers are utilized to represent the smoke plume, as well as each 1-km layer in the model domain. These simulations demonstrate that the elevated smoke plume is ingested by the simulated storm, and is distributed both upwards into the anvil (where aircraft measurements of biomass burning compounds (e.g. HCN) confirm that the smoke was lofted by the storm updraft) and downwards into the boundary layer. Additional simulations of more detailed aerosol and gas-phase chemistry provide insight on how the biomass-burning aerosols affect the storm characteristics. This presentation will show how aerosol distributions, rainfall, updraft velocities, and other storm properties change due to the presence of biomass-burning aerosols in the elevated smoke plume. The calculated changes caused by the biomass-burning aerosols determined by the WRF-Chem model will be compared with those estimated changes from the RAMS model to learn if the two models have consistent predictions.