Modeling Software for EHS Professionals

CALPUFF is a multi-layer, multi-species non-steady-state puff dispersion model which simulates the effects of time- and space-varying meteorological conditions on pollution transport, transformation, and removal. It includes algorithms for subgrid scale effects and longer range effects. It can be applied for long-range transport and for complex terrain. The CALPUFF modeling system is an important tool for regional haze (visibility) and fine particulate matter (e.g., PM2.5) impact assessments over distances hundreds of kilometers from emission sources and also applies for certain near-field applications involving complex meteorological conditions.

BREEZE CALPUFF offers a complete user graphical interface for the U.S. EPA-approved Version 5 and the advanced Version 6 of the CALPUFF modeling system, which includes:

  • CALMET - a diagnostic 3-dimensional meteorological model
  • CALPUFF - an air quality dispersion model
  • CALPOST - a post-processing package
  • Pre- and post-processors


BREEZE CALPUFF provides modelers with the tools and functionality required to perform air quality analyses that help to address both permitting, regulatory, and nuisance issues as well as perform academic research.

Key Features
  • Supports the latest U.S. EPA-approved version of the CALPUFF modeling system: CALPUFF Version 5.8.5, CALMET Version 5.8.5 and CALPOST Version 6.221
  • Supports one of Exponent's latest versions of the CALPUFF modeling system (version 6)
  • Updates map control to feature significant improvements to the Map view
  • Streamlines graphical user interface for more intuitive and easier dispersion modeling
  • Simplifies the setup of pre-modeling objects with a variety of utilities
  • Includes back compatibility with previous BREEZE CALPUFF projects
  • Integrates with the BREEZE 3D Analyst
  • Models numerous source types including point, area, volume, and buoyant line
  • Models numerous receptor types including discrete Cartesian grid, polar grid, and variable density grid
Product Tour

CALPUFF is an advanced non-steady-state meteorological and air quality modeling system developed by ASG scientists. It is maintained by the model developers and distributed by Exponent. The model has been adopted by the U.S. EPA in its Guideline on Air Quality Models as the preferred model for assessing long range transport of pollutants and their impacts on Federal Class I areas and on a case-by-case basis for certain near-field applications involving complex meteorological conditions.

Programs and Processors
BREEZE CALPUFF supports the basic U.S. EPA-approved programs. The BREEZE CALPUFF user interface provides modelers with more functionality and tools for analyzing results. The main components supported ::  learn more...
Integration with BREEZE 3D Analyst
BREEZE 3D Analyst is a powerful post-processor that enables you to analyze and visualize data in time series, contour plots, and 3D isosurface and plane views; and to visualize the intersection / unio ::  learn more...
CALPUFF takes into account the obstruction of wind flow from structures, such as buildings and point sources (i.e., stacks). Like any other model object in BREEZE CALPUFF, buildings can be copied and ::  learn more...
BREEZE CALPUFF allows you to model point, area, volume, and line sources. At least one source must be defined. BREEZE offers object array generators that create user defined arrays (e.g., polylines, p ::  learn more...
Receptors are locations where BREEZE CALPUFF will compute a concentration or deposition value. At least one receptor must be defined. ::  learn more...
Scenario Development Tools
BREEZE CALPUFF provides a variety of utilities to facilitate model setup or the analysis of results.Embedded Surfer (need to be pre-installed) link in BREEZE MAKEGEOCoordinate Converter to convert one ::  learn more...