Session 1, Unit 1
Course Overview
Introduction
Course – ENV 7335
Air Quality Modeling
Instructor – Yousheng Zeng, Ph.D., P.E.
Prerequisite – ENV 7331 or equivalent
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www.seas.smu.edu/env/7331
Course Objectives
Understand air pollution meteorology and
theory of atmospheric dispersion modeling
Be able to perform an air quality modeling
analysis using the most common regulatory
model – ISC3
Understand the regulatory requirements
related to air quality modeling analysis
Become knowledgeable of other air quality
models
Course Materials
Textbook –
“Atmospheric Dispersion Modeling Compliance
Guide”
with CD-ROM
by Schnelle & Dey
McGraw Hill, 1999
Other materials available on the Internet
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ISC3 Program and Manual
BPIP Program and Manual
Other relevant information
Course Outline
Session 1
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Introduction/Course overview
Basic meteorological principles
Session 2
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Air pollution climatology
Turbulence and the mixing process
Session 3
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The dispersion model
Dispersion coefficients
Course Outline
Session 4
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Plume rise
The effect of averaging time, multiple sources,
and receptors
Session 5
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Modeling in the presence of dispersion ceilings
SCREEN3, ISCPC, and midterm review
Session 6
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Chimney, building, and terrain effects
Midterm exam
Course Outline
Session 7
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Chimney design
The ISC3 Model
Session 8
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ISC3 practical issues and the BPIP program
Regulatory procedures and PSD modeling
Session 9
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Other important models – ISC-PRIME, AERMOD,
CALPUFF, UAM, CAMx
Final review
Course Outline
Session 10
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Modeling accidental releases
Final exam
Modeling exercise due
Modeling project report due
Course Work
Study problems at the end of each chapter in
the textbook
Modeling exercise
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use the ISCPC model in the textbook CD-ROM
20 practice problems in Appendix E
Earn credit by turning in answers for 10 of them
(even or odd numbers) to demonstrate completion
of the exercise
Midterm exam
Final exam
Course Work
Modeling Project
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EPA ISCST3 model and BPIP program
Multiple sources
Buildings and terrain
Receptor grid
1 year met data
Modeling report
Grading
Midterm exam 20 points
Final exam 30 points
Modeling exercise 10 points
Modeling Project 40 points
Total 100 points
Communication
Course website:
www.seas.smu.edu/env/7335
All students should send me a short
email at yz@wisedom.net so that I can
distribute announcement/materials if
necessary
Session 1, Unit 2
Basic meteorological principles
Atmosphere
Composition
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Near surface (tropospheric air)
 Nitrogen:
78.08%
 Oxygen:
20.95%
 Argon:
0.9%
 Contributors to atmospheric absorptive properties
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H2O:
CO2:
CH4:
N2O:
O3:
Variable
332 ppm
1.65 ppm
0.33 ppm
0.01-0.1 ppm
Atmosphere
Vertical temperature profile
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Troposphere
Stratosphere
Mesosphere
Thermosphere
Energy Balance
Radiation
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Occurs when an electron drops to a lower level of
energy
Blackbody radiation
 Emissivity of a blackbody at 6000 K (the sun)
 Emissivity of a blackbody at 300 K (the earth)
Energy balance
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Day vs. night
Local energy balance/out of balance
Global energy balance
Greenhouse effect
Scales of Atmospheric Motion
Microscale
Mesoscale
Synoptic (cyclonic scale)
Macroscale
General Circulation
General energy balance controls large
scale air movement
Air circulation if the earth did not turn
General circulation
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Rotation of the earth – Coriolis force
General circulation pattern
Geostrophic Layer
500-1000 m height
Two forces
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Horizontal pressure gradient
Coriolis force
Undisturbed constant air flow –
Geostrophic wind
Planetary Boundary Layer
Surface to 500 m high
Three forces
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Horizontal pressure gradient
Coriolis force
Frictional force due to earth’s surface roughness
Different wind from geostrophic wind
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Speed – retarded by friction
Direction – altered due to force balance
Urban/mountain vs. smooth surface
Surface layer – from surface to 50 m high
Impact of Fixed Geographic
Features
Sea breeze
Valley wind
Drainage wind
Flow patterns due to topographical
features