PB-Piedmont: A Numerical Model for Predicting the Movement of Biological Material near the Ground at Night

PB-Piedmont is a numerical model designed to simulate smoke movement at night under clear skies and near calm winds over irregular terrain similar to that of the Piedmont of the Southeastern United States. These are the conditions for which biological material, including smoke, some pollens, bacteria, and odor-producing compounds can be channeled by local terrain in unexpected directions for considerable distance with little dispersion. PB-Piedmont is designed to be run on a desktop computer by the non-technical land manager. This paper briefly describes the model design, valid predictive scales, assumptions and other limitations. Then, computer movies generated from model output are presented to show the accuracy of model simulations and to give examples of how local elevation differences on the scale of several 10's of meters redirect the near ground airflow during entrapment conditions at night.