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Alternative Models
This page lists some known alternative models to the perferred/recommended models listed in the
Guideline on Air Quality Models
that can be used in regulatory applications with case-by-case justification to the
Reviewing Authority (Section 3.2 of Appendix W). However, inclusion here does not confer any unique status relative to
other alternative models that are being or will be developed in the future.
The models in this section include
ADAM,
ADMS-3,
AFTOX,
ASPEN,
DEGADIS,
HGSYSTEM,
HOTMAC/RAPTAD,
HYROAD,
ISC3,
ISC-PRIME,
OBODM,
OZIPR,
Panache,
PLUVUEII,
SCIPUFF,
SDM, and
SLAB.
Alternative Models |
ADAM
Air Force Dispersion Assessment Model (ADAM) is a modified box and
Gaussian dispersion model which incorporates
thermodynamics, chemistry, heat transfer, aerosol loading, and dense gas
effects. Release scenarios include continuous and instantaneous,
area and point, pressurized and unpressurized, and
liquid/vapor/two-phased options.
Model Code
Executables (271KB,ZIP)
Model Documentation
Readme
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ADMS-3
Atmospheric Dispersion Modeling System (ADMS-3) is an advanced dispersion model for calculating concentrations of
pollutants emitted both continuously from point, line, volume and area
sources, or discretely from point sources. The model includes
algorithms which take account of the following: effects of main site
buiding; complex terrrain; wet deposition, gravitational settling and
dry deposition; short term fluctuations in concentration; chemical
reactions; radioactive decay and gamma-dose; plume rise as a function of
distance; jets and directional releases; averaging time ranging from
very short to annual; condensed plume visibility; meteorological
preprocessor.
The modeling system is
available at no cost in selected circumstances. Potential users
should contact Dr. David Carruthers at "David.Carruthers@cerc.co.uk"
for information on acquiring the ADMS-3 modeling system.
For additional information
on the ADMS-3 Modeling System please link to the
Cambridge Environmental
Research Consultants Website
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AFTOX
AFTOX is a Gaussian dispersion model that
will handle continuous or instantaneous liquid or gas elevated or
surface releases from point or area sources. Output consists of
concentration contour plots, concentration at a specified location, and
maximum concentration at a given elevation and time.
Model Code and Documentation
Executable/Test Case/Readme(173KB,ZIP)
User's Guide (26KB,ZIP) |
ASPEN
The Assessment System for Population Exposure Nationwide (ASPEN) consists of a
dispersion and a mapping module. The dispersion module is a Gaussian formulation
based on ISCST3 for estimating ambient annual average concentrations at a set of fixed receptors
within the vicinity of the emission source. The mapping module produces a
concentration at each census tract. Input data needed are emissions data,
meteorological data and census tract data. The Emissions Modeling System for Hazardous Pollutants
(EMS-HAP) is needed to
process the emission inputs into the ASPEN model or the
ISC3 model.
The ASPEN model was used in
estimating annual ambient concentrations for air toxics pollutant in the
National Air Toxics Assessment (NATA) Study.
Model Code
ASPEN Modeling System
Model Documentation
Descriptive Statement
User's Guide
The ASPEN model and the EMS-HAP Version 3.0 emission modeling system were used to
estimate the ambient concentrations for the National-Scale Air Toxics Assessment
for 1999. The results will be published in the Fall of 2005 on the Air Toxics
website. The 1996 results using EMS-HAP Version 2.0 and the ASPEN model, are still available on the
National Air Toxics Assessment (NATA)
Website.
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DEGADIS
DEGADIS simulates the
atmospheric dispersion at ground-level of area source dense gas (or
aerosol) clouds released with zero momentum into the atmospheric
boundary layer over flat, level terrain. The model describes the
dispersion processes which accompany the ensuing gravity-driven flow and
entrainment of the gas into the boundary layer.
Model Code
Code/Executable
(933KB,ZIP)
Model Documentation
User's Guide
Technical Document
Latest
Model Change Bulletin
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HGSYSTEM
HGSYSTEM is a collection of computer programs designed to predict the source-term
and subsequent dispersion of accidental chemical releases with an
emphasis on denser-than-air (dense gas) behavior. Available from
NTIS, Order Number PB96-501960. |
HOTMAC/RAPTAD
HOTMAC is a 3-dimensional Eulerian model for weather
forecasting; RAPTAD is a 3-dimensional Lagrangian random puff model for
pollutant transport and diffusion. These models are used for
prediction of transport and diffusion processes for complex terrain,
coastal regions, urban areas, and around buildings
where conventional models fail. Available from
YSA Corporation.
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HYROAD
The HYbrid ROADway Model (HYROAD) integrates three historically
individual modules that simulate the effects of traffic, emissions and
dispersion. The traffic module is a microscale transportation
model which simulates individual vehicle movement. The emission
module uses speed distributions from the traffic module to determine
composite emission factors; spatial and temporal distribution of
emissions is based on the vehicle operation simulations. The model
tracks vehicle speed and acceleration distributions by signal phase per
10-meter roadway segment for use in both emissions distribution and for
induced flows and turbulence. The dispersion module uses a Lagrangian puff formulation, along with a gridded non-uniform wind and
stability field derived from traffic module outputs, to describe
near-roadway dispersion characteristics. HYROAD is designed to
determine hourly concentrations of carbon monoxide (CO) or other
gas-phase pollutants, particulate matter (PM) and air toxics - in
consultation with appropriate Reviewing Authority - from vehicle emissions at receptor locations that
occur within 500 meters of the roadway intersections.
Model Code and Documentation
Executable/Test Case/README
(13.5 MB, ZIP)
Model Formulation
(1.8KB, ZIP)
User's Guide (1KB, ZIP) |
ISC3
ISC3 is a steady-state Gaussian plume model which can be used to
assess pollutant concentrations from a wide variety of sources
associated with an industrial complex. This model can account for
the following: settling and dry deposition of particles; downwash;
point, area, line, and volume sources; plume rise as a function of
downwind distance; separation of point sources; and limited terrain
adjustment. ISC3 operates in both long-term and short-term modes.
The screening version of ISC3 is SCREEN3.
ISC3 also uses the Emissions Modeling System for Hazardous Pollutants
(EMS-HAP)
to process an emission inventory for input into the model. The Building Profile Input Program
(BPIP)
and the Building Profile Input Program for PRIME (BPIPPRM)
can also be used with ISC3 to correctly calculate building heights (bh) and
projected building widths (pbw) for simple, multi-tiered, and groups of structures. For the status
of ISC3 as a preferred model, please see the Note
below.
Model Code
SHORT term (ISCST3) (1.7MB,ZIP)
LONG term (ISCLT3) (390KB,ZIP)
Model Documentation
User's Guide, Volume 1 with Addendum
User's Guide, Volume 2 with Addendum
Latest Model Change Bulletin for SHORT term (ISCST3)
Latest Model Change Bulletin for LONG term (ISCLT3)
Note: The promulgation package which establishes AERMOD as the preferred
air dispersion model in the Agency's "Guideline on Air Quality Models"
(Appendix W) in place of the ISC3 air dispersion model was signed by the
Administrator of the US EPA on October 21. The package was then submitted to
the Federal Register office and was published November 9, 2005.
This rule becomes effective December 9, 2005.
Beginning one year after this date, the new model -
AERMOD - should be used for
appropriate application as replacement for ISC3.
During this one-year period, protocols for modeling
analyses based on ISC3 which are submitted in a timely manner may be approved
at the discretion of the appropriate Reviewing Authority. Applicants are
therefore encouraged to consult with the Reviewing Authority as soon as
possible to assure acceptance during this period.
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ISC-PRIME
ISC-PRIME (Plume RIse Model Enhancements) is a model with building downwash incorporated
into the Industrial Source Complex Short Term Model
(ISCST3).
Model Code
Source Code (217k,zip)
Executables (639k,zip)
Model Documentation
README
User's Guide(235k)
Model Evaluation: ISCST3 & ISC-PRIME (262k,pdf)
- Graphics are not included in document. Complete copy is available from NTIS. (See README for ordering information.)
Consequence Analysis - Available from NTIS (See README for ordering information.)
Consequence Analysis for Adoption of PRIME: an
Advanced Building Downwash Model (22k, pdf)
and Associated Tables (24k, pdf)
Consequences Analysis of Using ISC-PRIME over
the Industrial Source Complex Short Term Model (903k,pdf)
Technical Papers
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)
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OBODM
Intended
for use in evaluating the potential air quality impacts of the open
burning and detonation (OB/OD) of obsolete munitions and solid
propellants. OBODM uses cloud/plume rise dispersion, and
deposition algorithms taken from existing models for instantaneous and
quasi-continuous sources to predict the downwind transport and
dispersion of pollutants released by OB/OD operations.
Model Code
Executable/Test Case (7/31/03)(372KB,ZIP)
Source Code (1.02MB,ZIP)
Model Documentation
README1 (errata and install
directions for version 1321)
README2(errata by
dates for version 1320)
User's Guide: Volume 1
User's Guide: Volume 2 |
OZIPR
OZIPR is a one-dimensional photochemical box model that is an
alternative version of the OZIP model
that deals with air toxic pollutants.
Model Code
Code/Executable/Test
Inputs (907KB,ZIP)
Model Documentation
README
User's Guide
Guidance Document
(Procedures for
applying City-Specific EKMA)
Support Document
(Also available from NTIS)
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
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Panache
Panache is an Eulerian (and Lagrangian for particulate matter),
3-dimensional finite volume fluid mechanics model designed to simulate
continuous and short-term pollutant dispersion in the atmosphere, in
simple or complex terrain. Available from
Transoft US. Inc.
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PLUVUEII
A model used for estimating visual range reduction and
atmospheric discoloration caused by plumes resulting from the emissions
of particles, nitrogen oxides, and sulfur oxides from a single source.
The model predicts the transport, dispersion, chemical reactions,
optical effects and surface deposition of point or area source
emissions.
Model Code
Code/Executable/Test Case (782KB,ZIP)
Model Documentation
User's Guide (40KB,ZIP)
Latest Model Change Bulletin
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SCIPUFF
Second-order Closure Integrated PUFF Model (SCIPUFF) is a Lagrangian puff dispersion model that uses
a collection of Gaussian puffs to predict three-dimensional, time-dependent pollutant concentrations.
In addition to the average concentration value, SCIPUFF provides a prediction of the statistical variance in the
concentration field resulting from the random fluctuations in the wind field.
Model Documentation
Model Overview
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SDM
Shoreline Dispersion Model (SDM) is a
multiple-point Gaussian dispersion model that can be used to determine
ground level concentrations from tall stationary point source emissions
near a shoreline.
Model Code
Code/Executable/Test Case (328KB,ZIP)
Model Documentation
Latest Model Change Bulletin
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SLAB
The SLAB model treats denser-than-air releases by
solving the one-dimensional equations of momentum, conservation of mass,
species, and energy, and the equation of state. SLAB handles
release scenarios including ground level and elevated jets, liquid pool
evaporation, and instantaneous volume sources.
Model Code
Code/Executable/Test Case (111KB,ZIP)
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