A coupled modeling system for connecting prescribed fire activity data through CMAQ for simulating regional scale air quality

The USDA Forest Service Southern High-Resolution Modeling Consortium (SHRMC) has developed a coupled prescribed fire-air chemistry modeling framework called the Southern Smoke Simulation System (SHRMC-4S). SHRMC-4S connects prescribed fire activity data with a combustion and emissions model, a plume model, the meteorological model MM5, and the EPA Community Multi-scale Air Quality model (CMAQ) to simulate and predict chemical concentrations of smoke components released during prescribed burns. Prescribed fires release particulate matter (PM), CO, SO2, NOx, and volatile organic compounds (VOC), which can degrade air quality. SHRMC-4S is designed to model regional scale air quality as the sum of the contributions to air quality of large numbers of burns each engineered to accomplish specified management objectives. Thus efforts by Southern land managers to minimize smoke impacts on regional air quality are part of the modeling in SHRMC-4S.

We present a description of SHRMC-4S. Then we present examples of PM and ozone concentrations from prescribed burns in Florida and Georgia. The results show that how the smoke is distributed vertically in the atmosphere is critical to bringing the smoke management aspect of prescribed burning into regional scale air quality. The sensitivity of CMAQ to the vertical distribution of smoke thus becomes a key factor in the overall accuracy of the simulations