Formulation of the Lagrangian particle model LAPMOD and its evaluation against Kincaid SF6 and SO2 datasets

•The theory behind a new Lagrangian particle model (LAPMOD) is described.•Directly coupled with CALMET, meteorological processor of the US-EPA CALPUFF model.•Coupled to AERMET output files through its LAPMET processor.•Detailed accounting of peak-to-mean concentration fluctuations, for odor modeling.•Evaluated against Kincaid SO2 and SF6 field experiments with good results.

This paper presents the Lagrangian particle model LAPMOD for modeling time-variable emissions in atmosphere of inert and radioactive gases and aerosols. LAPMOD is fully interfaced with the meteorological model CALMET (Scire et al., 1999a), part of the US-EPA recommended CALPUFF modeling system (EPA, 2017), and can also use the meteorological input files produced with the AERMET meteorological processor of US-EPA recommended model AERMOD (EPA, 2004).The paper outlines the theory on which LAPMOD is based and provides the results of the evaluation of LAPMOD against the Kincaid SF6 and SO2 classical field studies and tracer experiments. The performance of LAPMOD is successfully evaluated with the Model Evaluation Kit (Olesen, 2005) and compared with that of other air quality models.