Advanced Puff Dispersion Modeling System

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. The U.S. EPA recommends its use for regulatory applications on scales of tens to hundreds of kilometers.

BREEZE CALPUFF offers a complete user graphical interface for the U.S. EPA-approved Version 5 and the advanced Version 7 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.

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  • Supports Exponent's latest versions of the CALPUFF modeling system: CALPUFF Version 7.2.1, CALMET Version 6.5.0, CALPOST Version 7.1.0 and related processors
  • CALPUFF Version 7, which is incorporated in this latest version of BREEZE CALPUFF, introduces new source types such as roadways and flares
  • Enables the option to download high-resolution base maps for any location around the world, which can assure proper setup of model objects in the study domain and enhance graphical visualization
  • 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
  • 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

Programs and Processors

BREEZE CALPUFF enhances the basic U.S. EPA-approved programs providing modelers with more functionality and tools for analyzing results. The main components of the BREEZE CALPUFF modeling system are:CALMET - includes a diagnostic 3-dimensional meteorological model (considering slop flows, kinematic terrain effects, terrain blocking effects, and a divergence minimization procedure) and a micro-meteorological model for overland and overwater boundary layersCALPUFF - a non-steady-state Lagrangian... 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 / union of multiple data sets. It is useful for analyzing meteorological, terrain, and concentration data. Animated movies can be created for display in presentations and it is compatible with Golden Software's Surfer application and Google Earth. 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 pasted or drawn into the 2D display. Building information can be processed by the embedded U.S. EPA BPIP program. 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, polygons, and Cartesian grids) of the model object type. 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 coordinate to anotherA tool to blank on-site or off-site receptorsData Explorer to provide means of viewing project data in a Windows Explorer-like fashion. It is also referred to as Spreadsheet or Table view because model object data can be viewed, added, removed, and edited from within this view... Learn more


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