CALPUFF (CALPUFF)

Purpose

The CALPUFF model simulates the effects of time and space-varying meteorological conditions on pollution transport, transformation and removal.

Description

CALPUFF is an advanced non-steady-state meteorological and air quality modeling system. The model has been adopted by the U.S. Environmental Protection Agency (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. The modeling system consists of three main components and a set of preprocessing and post processing programs. The main components of the modeling system are CALMET (a diagnostic 3-dimensional meteorological model), CALPUFF (an air quality dispersion model), and CALPOST (a post processing package). Each of these programs has a graphical user interface (GUI).

CALPUFF is a multi-layer, multi-species non-steady-state puff dispersion model that simulates the effects of time- and space-varying meteorological conditions on pollution transport, transformation and removal. CALPUFF can be applied on scales of tens to hundreds of kilometers. It includes algorithms for subgrid scale effects (such as terrain impingement), as well as, longer range effects (such as pollutant removal due to wet scavenging and dry deposition, chemical transformation, and visibility effects of particulate matter concentrations).

CALPUFF is an advanced non-steady-state meteorological and air quality modeling system developed by Exponent scientists. It is maintained by the model developers and distributed by Exponent. The model has been adopted by the U.S. Environmental Protection Agency (USEPA) 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.

The modeling system consists of three main components and a set of preprocessing and postprocessing programs. The main components of the modeling system are CALMET (a diagnostic 3-dimensional meteorological model), CALPUFF (an air quality dispersion model), and CALPOST (a postprocessing package). Each of these programs has a graphical user interface (GUI). In addition to these components, there are numerous other processors that may be used to prepare geophysical (land use and terrain) data in many standard formats, meteorological data (surface, upper air, precipitation, and buoy data), and interfaces to other models such as the Penn State/NCAR Mesoscale Model (MM5), the National Centers for Environmental Prediction (NCEP) Eta/NAM and RUC models, the Weather Research and Forecasting (WRF) model and the RAMS model.

Regulatory Status

Some examples of applications for which CALPUFF may be suitable include:

• Near-field impacts in complex flow or dispersion situations
  • complex terrain
  • stagnation, inversion, recirculation, and fumigation conditions
  • overwater transport and coastal conditions
  • light wind speed and calm wind conditions
• Long range transport
• Visibility assessments and Class I area impact studies
• Criteria pollutant modeling, including application to State Implementation Plan (SIP) development
• Secondary pollutant formation and particulate matter modeling
• Buoyant area and line sources (e.g., forest fires and aluminum reduction facilities)

Latest Version	Version 5.8.5 December 2015
State of Development	Released and updated

Scope

Outcome Areas	Environmental
Management Domains	Air Quality
Subdomains	Air Quality Modelling
Spatial Resolutions	Unknown
Spatial Extents	Land or Business Unit, Local (i.e. Catchment or District)
Spatial Dimensions	3D
Temporal Resolutions	Hours, Days, Months
Temporal Extents	Hours, Days, Months
Steady State or Dynamic	Unknown
Level of Integration	Environmental

Input & Output Data

Key Input Data	Meterological
Input Data Formats	ASCI
Key Output Data	Runoff Fluxes of contaminants
Output Data Formats	ASCI, Image File(s)

Accessibility

Open/Closed Source	Closed Source
Licence Type	Need to Register to download - but free to use.

User Information

Operating Systems	Dos executable
User Interface	Graphical desktop
Ease of Use	Difficult Requires preparation of multiple data files and linking with supporting models
Use in Policy Process	Plan (Policy Formulation), Do (Policy Implementation), Review (Issue Identification)
Documentation	Download Page for CALPUFF Modelling System (button available to skip Registration) A User's Guide for the CALPUFF Dispersion Model http://www.src.com/calpuff/download/CALPUFF_UsersGuide.pdf Frequently Asked Questions http://www.src.com/calpuff/FAQ-questions.htm

Technical Considerations

Programming Language	Fortran
Analytical Techniques	Input/output
Model Structure	Overview of the program elements in the CALMET/CALPUFF Modelling System
Keywords	atmosphere, air quality, pollution, meteorology
Linkages to other Models	AMS/EPA Regulatory Model (AERMOD)
Links	MFE - Good Practice Guide to Dispersion Modelling Official CALPUFF Modelling System - Website USEPA Support Center for Regulatory Atmospheric Modeling (SCRAM) - Air Quality Dispersion Modeling - Preferred and Recommended Models CALPUFF - Wikipedia Page You Tube Videos on CALPUFF: CALPUFF and Odours Training Course 2013 - https://www.youtube.com/watch?v=C6xbdi5oDCw&list=PLf9jTKwtsTNmyGY51LhbmjnFIZzE51fi8 Air Pollution Modelling - https://www.youtube.com/watch?v=kdcMy_3d_co
Key References	Heydenrych, C., et.al. (2005): CALPUFF Model Validation in New Zealand  - Methodology and Issues. Kingett Mitchell Limited. Prepared for Foundation for Science and Technology. Bennett, M.J, M.E. Yansura, I.G. Hornyik, J.M. Nall, D.G. Caniparoli and C.G. Ashmore, 2002. Evaluation of the CALPUFF Long-range Transport Screening Technique by Comparison to Refined CALPUFF Results for Several Power Plants in Both the Eastern and Western United States. Proceedings of the Air & Waste Management Association's 95th Annual Conference, June 23-27, 2002; Baltimore, MD. Paper #43454. Levy, JI; Spengler, JD; Hlinka, D; Sullivan, D; Moon, D (2002): Using CALPUFF to evaluate the impacts of power plant emissions in Illinois: mode sensitivity and implications. Atmos. Environ. Vol 36(6):1063-1075. 3) Zhou, Y; Levy, JI; Hammitt, JK; Evans, JS (2003): Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China. Atmos. Environ. Vol. 37(6):815-826

Associated Case Studies