Observational and theoretical investigations of turbulent structures generated by low-Intensity prescribed fires in forested environments

As part of a broad Joint Fire Science Program (JFSP) project to develop modeling tools for predicting smoke dispersion from low-intensity prescribed fires (LIPFs), the USDA Forest Service - Northern Research Station conducted two LIPFs in 2011 and 2012 on forested plots in the New Jersey Pine Barrens (NJPB) to collect meteorological and air-quality data that can be used for model validation. Experimental investigations of the turbulence structures from the 2011 and 2012 LIPFs have been undertaken to provide further insight into the complex physical processes that govern turbulent energy production, turbulent eddy sizes, and turbulent diffusion of momentum and heat in the vicinity of LIPFs within forest vegetation layers. Using high frequency (10 Hz) measurements of temperatures and wind speeds using fine-wire thermocouples and sonic anemometers at multiple levels during the LIPFs, a quantitative description of LIPF flux-profile relationships are developed, with new information contained in the correlations and turbulence quantities. Characteristic turbulent structures before, during, and after fire-front passage are described through the LIPF flux-profile relationships.