Large eddy simulation for investigating coupled forest canopy and turbulence influences on atmospheric chemistry

We evaluate the mechanism against two more complex mechanisms using box modeling. We configure the LES for a temperate deciduous forest and summer midday weak-wind buoyancy-forced conditions. The multilayer canopy model necessitates estimates of reactant sources and sinks at each canopy level, and thus we describe multilayer parameterizations for dry deposition and biogenic emissions.

For the first time with an LES coupled to both a multilayer canopy and chemistry, we demonstrate variability in chemical reactions due to turbulence-induced segregation of reactants inside and just above the canopy. For the cases examined here, in-canopy segregation alters reaction rates that only consider well-mixed conditions by up to -48% to +23%. For many reactions, segregation is stronger when soil NO emissions reflect the upper bound of observed values for temperate forests.