This magnetic tape contains the FORTRAN source code, sample input data, and sample output data for the Photochemical Box Model (PBM). The PBM is a simple stationary single-cell model with a variable height lid designed to provide volume-integrated hour averages of O3 and other photochemical smog pollutants of interest for an urban area for a single day of simulation. The PBM is most appropriate for application in air stagnation conditions with light and variable winds. Horizontal dimensions of the box are typically on the order of 10-50 km; the vertical dimension may vary between 0.1 and 2 km. Chemical reactions are simulated using a 63-step kinetic mechanism that includes diurnal variation of photolytic rate constants. The depth of the mixed layer, or depth of the PBM domain, also follows a diurnal pattern; it can be optionally specified as following a non-linear growth curve. The PBM assumes that emission sources are homogeneously distributed across the surface face of the box volume and that the volume is well mixed at all times. Atmospheric diffusion and wind shear are neglected. Software Description: The program is written in the FORTRAN programming language for implementation on a UNIVAC1110 computer using the UNIVAC 1100 operating system Level 38R5A. 45K bytes of core storage are required to operate the model.

"November 1984." "EPA-600-8-84-022a."