Development and validation of a lagrangian model for dust generated by agricultural tilling

Human exposure to dust in and near farm fields is an increasing concern. This paper presents a dynamic lagrangian particle transport and dispersion model which simulates the field-scale dust dispersion from cotton field tilling. The major model inputs are the source strength (g/s, or particle numbers/s), the dynamic wind and turbulence (wind friction velocity, u*), wind direction, and atmospheric stability.. The particle concentrations in the air in 3-D can be obtained at any time. The model was programmed using C++ language, has a user-friendly interface with graphic output (4-D contours, x, y, z, and concentration). Model simulations are verified with remotely measured dust plume concentration and spread obtained by an elastic backscatter lidar. Multidimensional dimensional autocorrelation and cross-correlation analyses are used to quantify the model-lidar comparisons.