Exponent’s Atmospheric Sciences staff has experience serving a wide range of industrial and government clients around the world. Our scientists and engineers have been influential in the evolution of air quality modeling, and have developed or contributed to five of the seven U.S. EPA models recommended in the Guideline on Air Quality Models. Most notable of these is the CALPUFF model, an advanced non-steady-state meteorological and air quality modeling system recommended by the EPA as the preferred model for assessing long-range transport of pollutants and their impacts on Federal Class I areas or for near-field applications involving complex meteorological conditions.

CALPUFF is an advanced non-steady-state meteorological and air quality modeling system developed by Exponent’s atmospheric scientists. Version 7 includes new modules to assist with the modeling of roadways and flares along with other post-processing tools and model improvements.

CALApps Software

CALApps is Exponent’s new graphical user interface to the CALPUFF modeling system. The main features of CALApps include:

  • Windows 7/10 OS 32/64-bit compatible
  • Software for the main processors (CALMET, CALPUFF), post-processors (CALPOST, PRTMET), and geo-processors (CTGPROC, TERREL, MAKEGEO)
  • Option to apply project information to all processors, including modeling period, projection, and domain information
  • Toggle between direct “quick-edit” mode or traditional GUI screen mode
  • Software to visualize output1
    • Plot terrain and land use
    • Overlay meteorological fields including wind vectors, temperature, precipitation, mixing heights, and stability class
    • Quickly click layers on/off
    • Plot fields that vary with height by vertical layer
    • Overlay concentration contours
    • Animate layers and play animation with options to pause, step forward and backward, and increase/decrease playback speed
    • Save animation to animated GIF file which can be imported into PowerPoint as a picture or movie file
    • Save displayed image to picture file (BMP, JPG, GIF, etc.)
    • Options to import a custom base map, apply custom terrain and concentration contour levels, control the transparency of each layer, as well as other options
    • 1Some plotting features required Golden Software’s Surfer® plotting package.
  • Software to plot time series
    • Plot up to six time series simultaneously
    • Quickly click time series on/off
    • Zoom and pan
    • Hover over time series to view exact date/time and value of each plotted data point
    • Control the extents of the Y-axis with one click
    • Save displayed time series to picture file

For information on purchasing CALApps, please contact Irene Lee at ilee or Helaine Katz at hkatz

CALPUFF Downloads 

To download the latest version of the CALPUFF modeling system, including documentation, model codes and executables, and test case datasets click here.

If you have any questions, please email calpuff

CALPUFF Modeling Data

Links to many useful datasets containing terrain, land use, surface/upper air/buoy meteorological measurements and 3-D meteorological modeling data from WRF, MM5 and other models can be found on the CALPUFF Modeling Data page.

CALPUFF User Registration List

Please join the CALPUFF User List to receive notices of technical upgrades, model software upgrades, modeling tips, and training course announcements.

Click here for the Official CALPUFF Website


News & Events