Preferred/Recommended Models

These refined dispersion models are listed in Appendix W and are required to be used for State Implementation Plan (SIP) revisions for existing sources and for New Source Review (NSR) and Prevention of Significant Deterioration (PSD) programs. The models in this section include the following:

AERMOD Modeling System - A steady-state plume model that incorporates air dispersion based on planetary boundary layer turbulence structure and scaling concepts, including treatment of both surface and elevated sources, and both simple and complex terrain.

CALPUFF Modeling System - A 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 for long-range transport and for complex terrain.

Other Models - Other dispersion models including BLP, CALINE3, CAL3QHC/CAL3QHCR, CTDMPLUS, and OCD.

AERMOD Modeling System

The American Meteorological Society/Environmental Protection Agency Regulatory Model Improvement Committee (AERMIC) was formed to introduce state-of-the-art modeling concepts into the EPA's air quality models. Through AERMIC, a modeling system, AERMOD, was introduced that incorporated air dispersion based on planetary boundary layer turbulence structure and scaling concepts, including treatment of both surface and elevated sources, and both simple and complex terrain. There are two input data processors that are regulatory components of the AERMOD modeling system: AERMET, a meteorological data preprocessor that incorporates air dispersion based on planetary boundary layer turbulence structure and scaling concepts, and AERMAP, a terrain data preprocessor that incorporates complex terrain using USGS Digital Elevation Data. Other non-regulatory components of this system include: AERSCREEN, a screening version of AERMOD; AERSURFACE, a surface characteristics preprocessor, and BPIPPRIME, a multi-building dimensions program incorporating the GEP technical procedures for PRIME applications. Below is the model code and documentation for AERMOD Version 07026. The model code and supporting documents are not static but evolve to accommodate the best available science. Please check this website often for updates to model code and associated documents. As of December 9, 2006, AERMOD is fully promulgated as a replacement to ISC3, in accordance with Appendix W. AERMOD Implementation Guide AERMOD Implementation Guide - Provides information on the recommended use of AERMOD for particular applications and is an evolving document. (Updated Jan. 9, 2008.) Model Code Executable Source Code Test Cases Model Documentation README Model Change Bulletin #1 Model Change Bulletin #2 User's Guide and Addendum Model Formulation Document Addendum to the AERMOD Model Formulation Document - PVMRM technical description PVMRM and OLM Sensitivity Analysis Development and Evaluation of the PRIME Plume Rise and Building Downwash Model (19k,pdf) Project PRIME: Evaluation of Building Downwash Models Using Field and Wind Tunnel Data (32k,pdf) Development and Evaluation of the PRIME Plume Rise and Building Downwash Model (588k,pdf) Model Supporting Documents Model Evaluation Paper Bulk Richardson Number Evaluation Report Comparison of Regulatory Design Concentrations: AERMOD vs ISCST3, CTDMPLUS, ISC-PRIME Evaluation of Bias in AERMOD-PVMRM AERMOD Deposition Science Document AERMOD Deposition Parameterizations Document Draft Peer Review Document - For the AERMOD Deposition Parameterizations Document (above) Model Evaluation Databases README - Document that explains the databases below that contain input and output data for the model evaluation AGA (2.1MB,zip) - Input/output data for AGA: Flat, Rural, Downwash, Independent Alaska (0.7MB,zip) - Input/output data for Alaska: Flat, Rural Downwash, Developmental Baldwin (4.6MB,zip) - Input/output data for Bladwin: Flat, Rural, Non-downwash, Independent Bowline - Input/output data for Bowline: Flat, Rural, Downwash, Developmental/Independent (1.8 mb) Clifty Creek (3.5MB,zip) - Input/output data for Clifty Creek: Flat, Rural , Non-downwash, Independent DAEC (1.1MB,zip) - Input/output data for DAEC: Flat, Rural, Downwash, Developmental EOCR (4.3MB,zip) - Input/output data for EOCR: Flat, Rural, Downwash, Independent Indianapolis (1.3MB,zip) - Input/output data for Indianapolis: Flat, Urban, Non-downwash, Developmental Kincaid SF6 (3.1MB,zip) - Input/output data for Kincaid SF6: Flat, Rural, Non-downwash, Developmental Kincaid SO2 (5.6MB,zip) - Input/output data for Kincaid SO2: Flat, Rural, Non-downwash, Developmental Lee Wind Tunnel (13.4 MB,zip)- Input/output data for Lee Wind Tunnel: Flat, Rural, Downwash, Independent Lovett (9MB,zip) - Input/output data for Lovett: Terrain, Rural, Non-downwash, Developmental Martin's Creek (11.5MB,zip) - Input/output data for Martin's Creek: Terrain, Rural, Non-downwash, Independent Millstone (0.6MB,zip) - Input/output data for Millstone: Flat, Rural, Downwash, Developmental Prairie Grass (0.4MB,zip) - Input/output data for Prairie Grass: Flat, Rural, Non-downwash, Developmental Tracy (2.4MB,zip) - Input/output data for Tracy: Terrain, Rural, Non-downwash, Independent Westvaco (10.1MB,zip) - Input/output data for Westvaco: Terrain, Rural, Non-downwash, Independent

CALPUFF Modeling System

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 scavanging and dry deposition, chemical transformation, and visibility effects of particulate matter concentrations). --Please read the following before accessing the CALPUFF modeling system-- The files associated with this system, e.g., executables/source code, preprocessors, associated utilities, test cases, selected meteorological data sets and documentation can be found on TRC's website.  Support documents related to CALPUFF can be found on this website and are listed below.  TRC will provide updates and changes as necessary for the CALPUFF modeling system on their website.  Users entering the TRC website will have the opportunity to register their e-mail addresses in order to receive notices of any updates to the system.  This registration is voluntary and not necessary to access the system files. Upon entering the TRC website, you will see the CALPUFF Model listing on the left-hand panel.  To access the system code, click on "DOWNLOAD", then click on Skip Registration if you do not want to register. Go to TRC CALPUFF Regulatory Updates and Consequence Analysis **************************************************************************************************** ****** The current regulatory version of the CALPUFF Modeling System includes: ****** ******                                                                                                              ****** ******    CALPUFF version 5.8, level 070623                                                       ****** ******    CALMET version 5.8, level 070623                                                         ****** ******    CALPOST version 5.6394, level 070622                                                  ****** **************************************************************************************************** For every update of the "EPA-approved" version of the CALPUFF Modeling System, a consequence analysis is performed by EPA using an update protocol that identifies what model changes have been made and their implications based on the analysis results. This analysis compares the base CALPUFF Modeling System (i.e., current regulatory version) with the beta (i.e., proposed updated version). Based on this process, the supporting documentation and results for the most recent update will be available in this area in the near future. Items released for each update are (1) Model Change Bulletin(s), (2) model update reports, and (3) update results. Summary of Update Process Update Tool Executables MM5 file 1 MM5 data (file 1) for scenarios 2, 3, and 11; NOTE: 4 Gb MM5 file 2 MM5 data (file 2) for scenarios 2, 3, and 11; NOTE: 4 Gb Update Tool Documentation 06-29-07 UPDATE Model Change Bulletins MCB-B, MCB-C, MCB-D Model Update Report (to be provided soon) Update Results Support Documents A Comparison of CALPUFF Modeling Results To Two Tracer Field Experiments. (1998) 48 pages An Analysis of the Calmet/Calpuff Modeling System In A Screening Mode. (1998) 56 pages. A Comparison of CALPUFF with ISC3. (1998) 50 pages Application of CALMET/CALPUFF and MESOPUFF II to Compare Regulatory Design Concentrations for a Typical Long-Range Transport Analysis. (2002) 88 pp. Peer Review of Calmet/Calpuff Modeling System. (1998) 40 pp. Note: Part of Appendix F and all of Appendix G are unavailable in electronic form. Response to Peer Review Comments of Calmet/Calpuff Modeling System. (1998) 5 pages. Support Literature 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. 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

Other Preferred/Recommended Dispersion Models

BLP BLp is a Gaussian plume dispersion model designed to handle unique modeling problems associated with aluminum reduction plants, and other industrial sources where plume rise and downwash effects from stationary line sources are important. Model Code Code/Executable/Test Cases/Post-processors (213KB,ZIP) Model Documentation User's Guide User's Guide Addendum Model Change Bulletin

CALINE3 CALINE3 is a steady-state Gaussian dispersion model designed to determine air pollution concentrations at receptor locations downwind of  highways located in relatively uncomplicated terrain. CALINE3 is incorporated into the more refined CAL3QHC and CAL3QHCR models. Model Code Code/Executable/Test Case (53KB,ZIP) Model Documentation User's Guide Latest Model Change Bulletin

CAL3QHC/CAL3QHCR CAL3QHC is a CALINE3 based CO model with queuing and hot spot calculations and with a traffic model to calculate delays and queues that occur at signalized intersections; CAL3QHCR is a more refined version based on CAL3QHC that requires local meteorological data.  Both models are available below. Model Code Executables  for CAL3QHC and CAL3QHCR -- (323KB,ZIP) Model Documentation User's Guide --(131KB,ZIP) Latest Model Change Bulletin

CTDMPLUS Complex Terrain Dispersion Model Plus Algorithms for Unstable Situations (CTDMPLUS) is a refined point source gaussian air quality model for use in all stability conditions for complex terrain.  The model contains, in its entirety, the technology of CTDM for stable and neutral conditions. CTSCREEN is the screening version of CTDMPLUS. Model Code Code/Executable/Test Case (842KB,ZIP) Model Documentation User's Guide Supplement (12KB,ZIP) User's Guide, Volume 1 User's Guide, Volume 2 User's Guide for Terrain Preprocessor User's Guide for Meteorological Preprocessor Final Report available from NTIS Latest Model Change Bulletin

OCD Offshore and Coastal Dispersion Model Version 5 (OCD) is a straight line Gaussian model developed to determine the impact of offshore emissions from point, area or line sources on the air quality of coastal regions.  OCD incorporates overwater plume transport and dispersion as well as changes that occur as the plume crosses the shoreline.  Hourly meteorological data are needed from both offshore and onshore locations. Model Code Code/Executable (8.6MB, ZIP, Windows XP Compatible, 5/16/05) Model Documentation User's Guide (408 MB, ZIP) User's Guide Supplement Latest Model Change Bulletin

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