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Record Search Query:

Climatological Dispersion Model
Entry ID: CDM2-Model

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Summary

Abstract: (Summary adapted from EPA.)

CDM-2.0 (Climatological Dispersion Model - Version 2.0) determines long-term
(seasonal or annual) pollutant concentrations in a rural or urban setting using
average emission rates from point and area sources and a joint frequency
distribution of wind direction, wind speed, and stability. The algorithm is
based on Gaussian plume assumptions and is thus subject to the limitations of
non-reactive pollutants and a homogeneous wind field. Terrain in the modeling
region is assumed to be level or gently rolling. Computations can be made for
up to 200 point sources and 2500 area sources at an unlimited number of
receptor locations.

Related URL

Link: VIEW PROJECT HOME PAGE

Description: Support Center for Regulatory Air Models Home Page.

Link: VIEW RELATED INFORMATION

Description: Dispersion modeling uses mathematical formulations to characterize the
atmospheric processes that disperse a pollutant emitted by a source. Based on
emissions and meteorological inputs, a dispersion model can be used to predict
concentrations at selected downwind receptor locations. These air quality
models are used to determine compliance with National Ambient Air Quality
Standards (NAAQS), and other regulatory requirements such as New Source Review
(NSR) and Prevention of Significant Deterioration (PSD) regulations. These
models are addressed in Appendix A of EPA's Guideline on Air Quality Models
(also published as Appendix W of 40 CFR Part 51), which was originally
published in April 1978 to provide consistency and equity in the use of
modeling within the U.S. air quality management system. These guidelines are
periodically revised to ensure that new model developments or expanded
regulatory requirements are incorporated.

Link: VIEW RELATED INFORMATION

Description: Receptor Models

Receptor models are mathematical or statistical procedures for identifying and
quantifying the sources of air pollutants at a receptor location. Unlike
photochemical and dispersion air quality models, receptor models do not use
pollutant emissions, meteorological data and chemical transformation mechanisms
to estimate the contribution of sources to receptor concentrations. Instead,
receptor models use the chemical and physical characteristics of gases and
particles measured at source and receptor to both identify the presence of and
to quantify source contributions to receptor concentrations. These models are
therefore a natural complement to other air quality models and are used as part
of State Implementation Plans (SIPs) for identifying sources contributing to
air quality problems. The EPA has developed the Chemical Mass Balance (CMB) and
UNMIX models as well as the Positive Matrix Factorization (PMF) method for use
in air quality management. CMB fully apportions receptor concentrations to
chemically distinct source-types depending upon the source profile database,
while UNMIX and PMF internally generate source profiles from the ambient data.

Service Citation

Originators: EPA
Title: Climatological Dispersion Model
Provider: NTIS, NOAA
URL: http://www.epa.gov/scram001/userg/ntisinfo.txt

Service Keywords

MODELS >REGULATORY MODELS

MODELS >ATMOSPHERIC CHEMISTRY MODELS

Science Keywords

ATMOSPHERE >AEROSOLS >PARTICULATE MATTER

ATMOSPHERE >AIR QUALITY

ATMOSPHERE >ATMOSPHERIC WINDS

ATMOSPHERE >ATMOSPHERIC WINDS >WIND PROFILES

ISO Topic Category

CLIMATOLOGY/METEOROLOGY/ATMOSPHERE
ENVIRONMENT

Ancillary Keywords

Air Quality Models
EPA

Service Provider

DOC/NTIS > National Technical Information Service, U.S. Department of Commerce

Service Organization URL: http://www.ntis.gov/

Service Provider Personnel
Name: NTIS Phone: 703-487-4650 Phone: TELEX: 64617 Fax: 703-321-8547 Fax: 703-321-9038 Email: info at ntis.fedworld.gov Contact Address: National Technical Information Service (NTIS) U.S. Department of Commerce 5285 Port Royal Road City: Springfield Province or State: VA Postal Code: 22161 Country: USA

Personnel

DENNIS ATKINSON
Role: TECHNICAL CONTACT
Phone: 919-541-0518
Fax: 919-541-0044
Email: atkinson.dennis at epa.gov
Contact Address:
US EPA
Office of Air Quality Planning and Standards (OAQPS)
Technology Transfer Network
Mail Code D143-02
City: Research Triangle Park
Province or State: NC
Postal Code: 27711
Country: USA

Creation and Review Dates

SERF Creation Date: 2003-02-04
SERF Last Revision Date: 2007-05-31

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