View source for CALPUFF air pollution dispersion model

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{{Image|Crude oil-fired power plant.jpg|right|200px|An air pollution source.}} 

'''CALPUFF''' is an advanced, integrated [[Air pollution dispersion terminology|Gaussian puff]] modeling system for the simulation of [[Air pollution dispersion modeling|air pollution dispersion]].<ref name=Cleanair>[http://www.cleanairinfo.com/regionalstatelocalmodelingworkshop/documents/CALPUFF.pdf CALPUFF Status and Update]</ref>  

The model has been adopted by the [[U.S. Environmental Protection Agency]] (U.S. EPA) in its ''Guideline on Air Quality Models''<ref>[http://www.epa.gov/scram001/guidance/guide/appw_03.pdf Appendix W] of 40 [[Code of Federal Regulations|CFR]] Part 51</ref> as a [[Air pollution dispersion models#preferred and recommended models|preferred model]] for assessing long range transport of [[Air pollution|air pollutants]] and their impacts on national parks, wilderness areas and other Federal lands (known as Federal Class I areas) as well as on a case-by-case basis for certain near-field applications involving complex [[Meteorology|meteorological]] conditions.

==Description of the model==  

CALPUFF is an integrated modeling system consisting of three main modules and a set of pre-processing and post-processing programs. The main components of the modeling system are CALMET (a diagnostic 3-dimensional meteorological model), CALPUFF (an [[Air pollution dispersion modeling|air pollution dispersion model]]), and CALPOST (a post-processing module). Each of these modules has a [[graphical user interface]] (GUI). In addition to these modules, numerous other processors may be used to prepare [[geophysical]] (land use and terrain) data in many standard formats, meteorological data (surface, upper air and precipitation data), and interfaces to other models such as the [[Pennsylvania State University]]/[[National Center for Atmospheric Research|NCAR]] Mesoscale Model (MM5),<ref>[http://www.mmm.ucar.edu/mm5/ PSI/NCAR Mesoscale Model]</ref> and the Regional Atmospheric Modeling System  (RAMS)<ref>[http://rams.atmos.colostate.edu/rams-description.html An Introduction to the Regional Atmospheric Modeling System]</ref> meteorological model. 

The CALPUFF model is a non-steady-state Gaussian puff dispersion model designed to simulate the dispersion of [[Air pollution dispersion terminology|buoyant, puff or continuous]] [[Air pollution dispersion terminology|point and area pollution sources]] as well as the dispersion of buoyant, continuous [[Air pollution dispersion terminology|line]] sources. The model also includes [[algorithms]] for handling the effect of [[Air pollution dispersion terminology|downwash]] by nearby buildings in the path of the pollution plumes.<ref name=CARB>[http://www.ofcm.gov/atd_dir/pdf/calpuff.pdf General and Specific Characteristics of the model]</ref>

CALPUFF can be applied for long-range transport and for complex terrain.

==Example applications==

These are some typical examples of where the CALPUFF model has been used:<ref>[http://www.aqnis.pcd.go.th/tapce/plan/1Introduction%20slides.pdf CALPUFF Modeling Course] (Chulalongkorn University, Bangkok, Thailand, 2005)</ref><ref>[http://www.epsilonassociates.com/site/index.php/item/351 White Oak Energy Center]</ref><ref>[http://www.colorado.gov/airquality/documents/NIXON%20-%20Supplemental%20CALPUFF%20Modeling%20Results.pdf Ray D. Nixon Power Plant]</ref><ref>[http://www.cosis.net/abstracts/EGU04/06342/EGU04-J-06342-1.pdf Assessing Volcanic Ash Dispersal at Mt. Etna Using the CALPUFF Modeling System]</ref>

* Aluminium smelter: [[Columbia River Valley]]
* Copper smelter: [[Chile]]
* Power plant: [[New Jersey (U.S. state)|New Jersey]]
* Power Plant: [[Virginia]]
* Power plant: [[Colorado (U.S. state)|Colorado]]
* Chemical plant: [[West Virginia]]
* Natural gas development: [[Colorado (U.S. state)|Colorado]], [[Utah]] and [[Wyoming]]
* Hazardous waste incinerator: [[Ohio (U.S. state)|Ohio]]
* Volcanic ash dispersion: [[Mt. Etna]], [[Italy]]

==History==

The CALPUFF model was originally developed by the Sigma Research Corporation (SRC) in the late 1980s under contract with the [[California Air Resources Board]] (CARB)<ref name=CARB/> and it was first issued in about 1990.<ref>[http://www.arb.ca.gov/research/apr/past/a025-2a.pdf Model Formulation and Users Guide for the CALPUFF model, May 1990]</ref>

The Sigma Research Corporation subsequently became part of Earth Tech, Inc. After the US EPA designated CALPUFF as a preferred model in their ''Guideline on Air Quality Models'', Earth Tech served as the designated distributor of the model. 

In April 2006, ownership of the model switched from Earth Tech to the TRC Environmental Corporation, who are currently (August 2006) responsible for maintaining and distributing the model.<ref name=Cleanair/>   

==References==
{{reflist}}

==Further reading==

For those who are unfamiliar with air pollution dispersion modeling and would like to learn more about the subject, it is suggested that either one of the following books be read:

*{{cite book | author=Turner, D.B. | title=[[Workbook of Atmospheric Dispersion Estimates]]| edition=2nd Edition| publisher=CRC Press | year=1994 | id=ISBN 1-56670-023-X}} [http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=L1023&parent_id=&pc= www.crcpress.com]

*{{cite book | author=Schnelle, Jr., Karl B. and Dey, Partha R. | title=Atmospheric Dispersion Modeling Compliance Guide| publisher=McGraw-Hill | year=2000 | id=ISBN 0-07-058059-6}} 

*{{cite book|author=Beychok, Milton R.|title=[[Fundamentals of Stack Gas Dispersion]]|edition=4th Edition|publisher=author-published|year=2005|id=ISBN 0-9644588-0-2}}