This page last reviewed August 10, 2009

Software and Data from the
Modeling and Meteorology Branch

General Information

The Air Resources Board charges standard fees for providing software and data. The fee for models covers our cost to copy and ship the model, test input and output files, and documentation. The software and test files can provided on MS-DOS diskettes; 4mm, 8mm, or 9-Track tape; or by ftp. Documentation and files will be sent by first-class mail. Currently the documentation is only available in printed form.

NOTE: No fee applies to software or data downloaded directly from this web page.

There is a base charge of $60.00 plus $15.00 per file for providing data maintained by the Modeling and Meteorology Branch. The base charge covers copying, mailing, and handling. An additional charge of $30.00 per 9-Track tape or $12.00 per 4mm/8mm tape is required if the requester does not provide the tape media. Manuals or other documentation can be ordered at a cost of $5.00 per 150 pages.

Government and educational organizations can be billed for orders greater than $100.00. California sales tax (7.75%) is charged on orders shipped to California addresses. Orders shipped to addresses outside of the United States are charged an additional $5.00. For overnight requests, the recipient can provide their shipping account number or add $7.00.

Orders can be taken by phone or e-mail but we require that they be followed with a written request. Please make your written request to:

Mr. John DaMassa, Chief
Modeling and Meteorology Branch
Technical Support Division
California Air Resources Board
Post Office Box 2815
Sacramento, California 95812 USA
FAX: 916-327-8524

All software are written in FORTRAN and are provided as source code. A fortran compiler will be required to use these programs. We have successfully implemented these models on a variety of platforms including Intel386 based PCs, UNIX workstations, and Cray Supercomputers. When implemented on personal computers additional memory, additional disk space, and a DOS extender may be required to run real-world problems.

Models developed by or under contract to the Air Resources Board are in the Public Domain and you may obtain and copy the model and its documentation from colleagues without a fee. We only charge a fee to recover the cost of providing these materials as required by agency policy. If you order a package from the ARB we can answer some basic questions but we cannot provide detailed assistance in installation or application of these models.

California Photochemical Grid Model (CALGRID)

CALGRID is a photochemical grid model and is distributed by the Modeling and Meteorology Branch. CALGRID has not been fully evaluated and has not been approved for routine regulatory use in California. The model as currently distributed uses the 1990 SAPRC chemical mechanism. We will provide revisions at no additional cost as they become available. CALGRID comes with some sample emissions processing routines, and software for chemical mechanism generation. It should be noted that it will be necessary to develop your own emissions pre-processors. While CALGRID does not have a post-processor, the output files from CALGRID are compatible with the CALMET post-processor.

A bug fix for the ZTRANS.FOR routine that deals with computation of dry deposition has been found and can be downloaded here. There is also an experimental KZ_LASAT routine, using the LASAT KZ equations, included in the bug-fix zip file.

A mailing list has been setup for the CALGRID model. It can be accessed at

Version: 1.6B/S90 (October 18, 1994)

Fee: $100.00

Contact: Mr. Donald Johnson
Modeling and Meteorology Branch
Voice: 916-445-0962, FAX: 916.327.8524

Download: CALGRID Version 1.6B, zip'd archive (850 KB)
CALGRID Version 1.6B, gzip'd tar archive (846 KB)
Bug fix for ZTRANS.FOR and experimental KZ_LASAT routine, zip'd archive (8.5 KB)
CALGRID User's Guide (469 KB)
CALGRID Model Formulation Document (325 KB)

Census Data Gridding Program (CDGP)

The CDGP is used to allocate census or other data from irregular areas (described as polygons) to regularly spaced grid cells using the method of polygon overlays. This package includes the FORTRAN code of the census data gridding program and sample input file. A User's Guide is available for download below.

Version: October 28, 1993

Download:, zip'd archive (15k)
Download: CDGP_UG.pdf, CDGP User's Guide (864k)

Contact: Donald P. Johnson
Modeling and Meteorology Branch
Voice: 916-445-0962, FAX: 916.327.8524


The California Air Resources Board retained Professor Michael Kleeman of University of California, Davis to develop a parallel version of the CALPUFF dispersion model. This work was based on version 5.8 - level 070623, which was the USEPA preferred version at the time when the project started. This modified version of CALPUFF has not been designated as a preferred model by USEPA. Eventually, a newer version of CALPUFF than 5.8 - level 070623 may be preferred by the USEPA for use in NAAQS compliance demonstration modeling applications. To determine the current regulatory version of the CALPUFF Modeling System, please refer to the USEPA Technology Transfer Network, Support Center for Regulatory Atmospheric Modeling website:

For modeling applications that are subject to USEPA approval, the acceptability of an alternative model is determined by the USEPA Regional Office. With regard to gaining approval for use of alternative models under such circumstances, the burden of proof is on the applicant to provide an adequate demonstration of equivalency, subject to USEPA Regional Office acceptance, before the model can be used as the basis for regulatory modeling demonstrations. Use of alternative models is discussed in the Guideline on Air Quality Models (Appendix W to 40 CFR Part 51), Section 3.2.

For modeling applications that are not subject to approval of USEPA, consent should be sought from appropriate approving agency before the modeling exercises are executed.

Version: May 2013

Contact: Shuming Du
Modeling and Meteorology Branch
Voice: 916-327-5768

Download: Parallel CALPUFF (12 MB)