Important parameters for smoke plume rise simulation with Daysmoke
Daysmoke is a local smoke transport model and has been used to provide smoke plume rise information. It includes a large number of parameters describing the dynamic and stochastic processes of particle upward movement, fallout, fluctuation, and burn emissions. This study identifies the important parameters for Daysmoke simulations of plume rise and seeks to understand their impacts on regional air quality simulations with the Community Multiscale Air Quality (CMAQ) model. The Fourier Amplitude Sensitivity Test (FAST) was first applied to Daysmoke simulations of prescribed burning in the southeastern U.S. It is shown that, for the specified value ranges of 15 parameters, entrainment coefficient and number of updraft cores are the most important for determining smoke plume rise. Initial plume temperature anomaly, diameter of flaming area, and thermal stability also contribute to a certain extent. CMAQ simulations were then conducted for a couple of different updraft core numbers. The simulated ground PM2.5 concentration is much closer to the measurements with multiple updraft cores than single core. The results from this study therefore suggest that simulations of Daysmoke and CMAQ could be improved by a better understanding of plume structure to aid in specifying the number of smoke updraft cores.