LAPMOD User Manual - Version 20260908

LAPMOD is a tridimensional and non-stationary Lagrangian particle model that simulates the atmospheric dispersion of inert or radioactive substances that are emitted as gases or aerosols. Besides conventional pollutants, LAPMOD can simulate the dispersion of odors. The particles used for the calculation move in the atmosphere, driven by mean wind (advection) and turbulence (diffusion). Each particle carries a fraction of the emitted mass. At each instant, it is possible to compute the concentration and the deposition at receptors by considering the position of the particles and their masses. LAPMOD is implemented in FORTRAN and it is fully coupled with the diagnostic meteorological model CALMET (up to latest version 6.5.0) that provides all the required information about wind speed and direction, and turbulence parameters. LAPMOD can also be used with the meteorology provided by the meteorological model WRF, using the US-EPA postprocessor MMIF (Mesoscale Model Interface Program).The files produced by LAPMOD can be postprocessed using LAPOST to compute the statistics of interest on the results. The LAPMOD modeling system also includes LAPEMI, a preprocessor used to generate emission input files with temporal modulation. Finally, concentrations can also be calculated starting from particle masses by means of the LAPCON post processor.