Air Dispersion Modeling Foundations and Applications

A single reference to all aspects of contemporary air dispersion modeling

The practice of air dispersion modeling has changed dramatically in recent years, in large part due to new EPA regulations. Current with the EPA's 40 CFR Part 51, this book serves as a complete reference to both the science and contemporary practice of air dispersion modeling. Throughout the book, author Alex De Visscher guides readers through complex calculations, equation by equation, helping them understand precisely how air dispersion models work, including such popular models as the EPA's AERMOD and CALPUFF.

Air Dispersion Modeling begins with a primer that enables readers to quickly grasp basic principles by developing their own air dispersion model. Next, the book offers everything readers need to work with air dispersion models and accurately interpret their results, including:

• Full chapter dedicated to the meteorological basis of air dispersion
• Examples throughout the book illustrating how theory translates into practice
• Extensive discussions of Gaussian, Lagrangian, and Eulerian air dispersion modeling
• Detailed descriptions of the AERMOD and CALPUFF model formulations

This book also includes access to a website with Microsoft Excel and MATLAB files that contain examples of air dispersion model calculations. Readers can work with these examples to perform their own calculations.

With its comprehensive and up-to-date coverage, Air Dispersion Modeling is recommended for environmental engineers and meteorologists who need to perform and evaluate environmental impact assessments. The book's many examples and step-by-step instructions also make it ideal as a textbook for students in the fields of environmental engineering, meteorology, chemical engineering, and environmental sciences.

Preface xv

List of Symbols xix

Chapter 1 Introduction 1

1.1 Introduction 1

1.2 Types of Air Dispersion Models 4

1.3 Standard Conditions for Temperature and Pressure 6

1.4 Concentration Units in the Gas Phase 7

1.5 Units 9

1.6 Constants and Approximately Constant Variables 11

1.7 Frequently Used Greek Symbols 12

Problems 12

References 12

Chapter 2 An Air Dispersion Modeling Primer 14

2.1 Introduction 14

2.2 Basic Concepts of Air Dispersion 15

2.3 Gaussian Dispersion Model 17

2.4 Plume Rise 30

2.5 Need for Refinements to the Basic Gaussian Plume Dispersion Model 34

Problems 34

Materials Online 36

References 36

Chapter 3 Air Pollutants: An Overview 37

3.1 Introduction 37

3.2 Types of Air Pollution 37

Problems 51

References 52

Chapter 4 Regulation of Air Quality and Air Quality Modeling 54

4.1 Introduction 54

4.2 Air Quality Regulation 54

4.3 Air Dispersion Modeling Guidelines 59

References 59

Chapter 5 Meteorology for Air Dispersion Modelers 60

5.1 Introduction 60

5.2 Structure of the Atmosphere 61

5.3 Altitude Dependence of Barometric Pressure 62

5.4 Height Dependence of Temperature—Adiabatic Case 65

5.5 Stability 70

5.6 Heat Balance 76

5.7 Wind Speed Profile 81

5.8 Temperature Profile Revisited: Nonneutral Conditions 93

5.9 Heat Balance Revisited: Stable Conditions 97

5.10 Mixing Layer Height 99

5.11 Concept of Turbulence 103

5.12 Special Topics in Meteorology 119

5.13 Advanced Topics in Meteorology 122

5.14 Summary of Main Equations 134

Problems 137

Materials Online 138

References 139

Chapter 6 Gaussian Dispersion Modeling: An In-Depth Study 141

6.1 Introduction 141

6.2 Gaussian Plume Models 142

6.3 Parameterizations Based on Stability Classes 145

6.4 Gaussian Plume Dispersion Short Cut 148

6.5 Plume Dispersion Modifiers 150

6.6 Continuous Parameterization for Gaussian Dispersion Models 153

6.7 Gaussian Plume Models for Nonpoint Sources 172

6.8 Virtual Source Concept 174

6.9 Special Issues 175

6.10 Gaussian Puff Modeling 180

6.11 Advanced Topics in Meteorology 187

6.12 Summary of the Main Equations 193

Problems 195

Materials Online 197

References 197

Chapter 7 Plume–Atmosphere Interactions 201

7.1 Introduction 201

7.2 Plume Rise 201

7.3 Plume Downwash: PRIME (Plume RIse Model Enhancements) 215

7.4 Behavior of Denser-than-Air Plumes 225

7.5 Deposition 234

7.6 Summary of the Main Equations 288

Problems 291

Materials Online 292

References 292

Chapter 8 Gaussian Model Approaches in Urban or Industrial Terrain 296

8.1 Introduction 296

8.2 Wind Flow around Obstacles 297

8.3 Surface Roughness and Displacement Height in Urban and Industrial Terrain 298

8.4 Wind Speed Profiles near the Surface: Deviations from Similarity Theory 303

8.5 Turbulence in Urban Terrain 314

8.6 Dispersion Calculations in Urban Terrain near the Surface 317

8.7 An Example 320

8.8 Summary of the Main Equations 324

Problems 326

Materials Online 327

References 327

Chapter 9 Stochastic Modeling Approaches 329

9.1 Introduction 329

9.2 Fundamentals of Stochastic Air Dispersion Modeling 330

9.3 Numerical Aspects of Stochastic Modeling 348

9.4 Stochastic Lagrangian Calculation Examples 353

9.5 Summary of the Main Equations 358

Problems 359

Materials Online 360

References 360

Chapter 10 Computational Fluid Dynamics and Meteorological Modeling 363

10.1 Introduction 363

10.2 CFD Model Formulation: Fundamentals 364

10.3 Reynolds-Averaged Navier–Stokes (RANS) Techniques 375

10.4 Large Eddy Simulation (LES) 394

10.5 Numerical Methods in CFD 397

10.6 Meteorological Modeling 399

10.7 Summary of the Main Equations 400

References 402

Chapter 11 Eulerian Model Approaches 404

11.1 Introduction 404

11.2 Governing Equations of Eulerian Dispersion Models 405

11.3 Closing the Material Balance for Turbulent Motion 412

11.4 Atmospheric Chemistry 422

11.5 Numerical Aspects of Eulerian Dispersion Modeling 455

11.6 Summary of the Main Equations 467

Problems 469

References 470

Chapter 12 Practical Aspects of Air Dispersion Modeling 474

12.1 Introduction 474

12.2 Source Characterization and Source Modeling 474

12.3 Coordinate Systems 476

12.4 Data Handling 478

12.5 Model Validation 478

References 479

Chapter 13 ISC3 and SCREEN3: A Detailed Description 480

13.1 Introduction 480

13.2 ISC3 Model Description 480

13.3 SCREEN3 Model Description 489

References 490

Chapter 14 AERMOD and AERMET: A Detailed Description 491

14.1 Introduction 491

14.2 Description of AERMET 492

14.3 Description of AERMOD 496

References 512

Chapter 15 CALPUFF and CALMET: A Detailed Description 514

15.1 Introduction 514

15.2 Description of CALMET 515

15.3 Description of CALPUFF 526

References 541

Chapter 16 CMAQ: A Brief Description 542

16.1 Introduction 542

16.2 Main Features of CMAQ 542

16.3 Advection and Diffusion Modeling in CMAQ 544

16.4 Atmospheric Chemistry Modeling in CMAQ 545

References 554

Appendix A Auxiliary Calculations and Derivations 556

Appendix B Auxiliary Da ta and Methods 596

Appendix C Theory of Near Surface Turbulence Applied to Wind Speed Profiles, Dry Deposition, Air–Water Exchange, and Canopy Effects 607

Index 629

ALEX DE VISSCHER, PhD, is the Canada Research Chair in Air Quality and Pollution Control Engineering at the University of Calgary. Dr. De Visscher has published his findings in a wide range of areas, including air quality and waste gas treatment, advanced oxidation, solution chemistry, and greenhouse gas emissions. In addition, he has published a volume of the IUPAC-NIST Solubility Data Series dedicated to alkaline earth carbonates. Among his honors and accolades, Dr. De Visscher is a recipient of the University of Calgary's Killam Emerging Research Leader Award.