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

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  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

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 [email protected]

necessary so that I can distribute announcement/materials if

Session 1, Unit 2

Basic meteorological principles

Atmosphere

Composition  Near surface (tropospheric air)     Nitrogen: Oxygen: Argon: 0.9% Contributors to atmospheric absorptive properties      H 2 O: CO 2 : CH 4 : N 2 O: O 3 : 78.08% 20.95% Variable 332 ppm 1.65 ppm 0.33 ppm 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