As part of achieving this goal, the Advanced Regional Prediction System (ARPS) atmospheric model has been modified to allow simulation of flow through a multi-layer canopy. The effects of vegetation elements (e.g., branches, leaves) on drag, turbulence production/dissipation, and the surface energy budget are accounted for through modifications to the ARPS model equations. Three-dimensional vegetation density data obtained from LIDAR measurements are used to initialize the canopy model. To account for the first order effects of a wildland fire, upward sensible heat fluxes are imposed within a fixed area of the model domain, with fire intensity derived from observed data. As a final step in the development process, ARPS has been coupled to the Pacific Northwest National Laboratory (PNNL) Integrated Lagrangian Transport (PILT) model.
This paper presents results from a recent modeling case study of a March 2011 prescribed burn in the New Jersey Pine Barrens. To accurately represent regional and local forcing within the region of the burn, a series of one-way nested simulations are executed, spanning from 9-km to 100-m horizontal grid spacing. Momentum, scalar, and turbulence fields are compared between the innermost domain simulation and data obtained from a series of flux towers located inside and outside of the burn unit. This work is one part of a coordinated effort to evaluate the performance of atmospheric dispersion modeling systems; papers detailing data analysis efforts as well as smoke dispersion modeling will be presented elsewhere at the conference.