Wildfire Impact on Environmental Thermodynamics and Severe Convective Storms

Wildfires are extreme events associated with weather, climate, and environment, and have been increasing globally in frequency, burn season length, and burned area. It is of great interest to understand the impacts of wildfires on severe convective storms through releasing heat and aerosols into the atmosphere. We have developed a model capability that can account for the impact of sensible heat fluxes from wildfires on thermodynamics and is computationally efficient. The pyrocumulonimbus clouds associated with the Texas Mallard Fire on 11-12 May 2018 are well simulated by accounting for both heat and aerosols emitted from the wildfire. Both heat and aerosol effects increase low-level temperatures and mid-level buoyancy, and enhance convective intensity. Intensified convection along with more supercooled liquid condensate due to stronger vertical transport results in larger hailstones and enhanced lightning. The effects of heat flux on the convective extremes are more significant than those of aerosol emissions.