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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 www.seas.smu.edu/env/7331. Course Objectives.
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Introduction • Course – ENV 7335Air Quality Modeling • Instructor – Yousheng Zeng, Ph.D., P.E. • Prerequisite – ENV 7331 or equivalent • 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-ROMby Schnelle & DeyMcGraw Hill, 1999 • Other materials available on the Internet • ISC3 Program and Manual • BPIP Program and Manual • Other relevant information
Course Outline • Session 1 • Introduction/Course overview • Basic meteorological principles • Session 2 • Air pollution climatology • Turbulence and the mixing process • Session 3 • The dispersion model • Dispersion coefficients
Course Outline • Session 4 • Plume rise • The effect of averaging time, multiple sources, and receptors • Session 5 • Modeling in the presence of dispersion ceilings • SCREEN3, ISCPC, and midterm review • Session 6 • Chimney, building, and terrain effects • Midterm exam
Course Outline • Session 7 • Chimney design • The ISC3 Model • Session 8 • ISC3 practical issues and the BPIP program • Regulatory procedures and PSD modeling • Session 9 • Other important models – ISC-PRIME, AERMOD, CALPUFF, UAM, CAMx • Final review
Course Outline • Session 10 • 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 • 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 • EPA ISCST3 model and BPIP program • Multiple sources • Buildings and terrain • Receptor grid • 1 year met data • Modeling report
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
Atmosphere • Composition • Near surface (tropospheric air) • Nitrogen: 78.08% • Oxygen: 20.95% • Argon: 0.9% • Contributors to atmospheric absorptive properties • H2O: Variable • CO2: 332 ppm • CH4: 1.65 ppm • N2O: 0.33 ppm • O3: 0.01-0.1 ppm
Atmosphere • Vertical temperature profile • Troposphere • Stratosphere • Mesosphere • Thermosphere
Energy Balance • Radiation • 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 • 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 • Rotation of the earth – Coriolis force • General circulation pattern
Geostrophic Layer • 500-1000 m height • Two forces • Horizontal pressure gradient • Coriolis force • Undisturbed constant air flow – Geostrophic wind
Planetary Boundary Layer • Surface to 500 m high • Three forces • Horizontal pressure gradient • Coriolis force • Frictional force due to earth’s surface roughness • Different wind from geostrophic wind • 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