Environmental Physics

Egbert Boekeris a retired Professor from the Free University of Amsterdam with a career in which he taught virtually all of the undergraduate courses in physics. Rienk van Grondelle is a Professor in the Department of Biophysics and Physics of Complex Systems at the Free University of Amsterdam. He is performing research in biophysics and teaching not only to physics students but also to biology students. He is a member of the Royal Netherlands Academy of Sciences.

Preface xiii

Acknowledgements xv

1 Introduction 1

1.1 A Sustainable Energy Supply 1

1.2 The Greenhouse Effect and Climate Change 3

1.3 Light Absorption in Nature as a Source of Energy 4

1.4 The Contribution of Science: Understanding, Modelling and Monitoring 5

Exercises 6

References 6

2 Light and Matter 7

2.1 The Solar Spectrum 7

2.1.1 Radiation from a Black Body 7

2.1.2 Emission Spectrum of the Sun 9

2.2 Interaction of Light with Matter 12

2.2.1 Electric Dipole Moments of Transitions 12

2.2.2 Einstein Coefficients 14

2.2.3 Absorption of a Beam of Light: Lambert-Beer’s Law 16

2.3 Ultraviolet Light and Biomolecules 19

2.3.1 Spectroscopy of Biomolecules 20

2.3.2 Damage to Life from Solar UV 21

2.3.3 The Ozone Filter as Protection 22

Exercises 28

References 28

3 Climate and Climate Change 31

3.1 The Vertical Structure of the Atmosphere 32

3.2 The Radiation Balance and the Greenhouse Effect 36

3.2.1 Simple Changes in the Radiation Balance 39

3.2.2 Radiation Transfer 41

3.2.3 A Simple Analytical Model 44

3.2.4 Radiative Forcing and Global Warming 45

3.2.5 The Greenhouse Gases 48

3.3 Dynamics in the Climate System 51

3.3.1 Horizontal Motion of Air 53

3.3.2 Vertical Motion of Ocean Waters 58

3.3.3 Horizontal Motion of Ocean Waters 59

3.4 Natural Climate Variability 59

3.5 Modelling Human-Induced Climate Change 62

3.5.1 The Carbon Cycle 63

3.5.2 Structure of Climate Modelling 66

3.5.3 Modelling the Atmosphere 67

3.5.4 A Hierarchy of Models 70

3.6 Analyses of IPCC, the Intergovernmental Panel on Climate Change 70

3.7 Forecasts of Climate Change 70

Exercises 74

References 76

4 Heat Engines 77

4.1 Heat Transfer and Storage 78

4.1.1 Conduction 79

4.1.2 Convection 82

4.1.3 Radiation 82

4.1.4 Phase Change 83

4.1.5 The Solar Collector 84

4.1.6 The Heat Diffusion Equation 87

4.1.7 Heat Storage 90

4.2 Principles of Thermodynamics 91

4.2.1 First and Second Laws 91

4.2.2 Heat and Work; Carnot Efficiency 95

4.2.3 Efficiency of a ‘Real’ Heat Engine 97

4.2.4 Second Law Efficiency 98

4.2.5 Loss of Exergy in Combustion 101

4.3 Idealized Cycles 103

4.3.1 Carnot Cycle 103

4.3.2 Stirling Engine 104

4.3.3 Steam Engine 105

4.3.4 Internal Combustion 107

4.3.5 Refrigeration 110

4.4 Electricity as Energy Carrier 113

4.4.1 Varying Grid Load 114

4.4.2 Co-Generation of Heat and Electricity 115

4.4.3 Storage of Electric Energy 117

4.4.4 Transmission of Electric Power 123

4.5 Pollution from Heat Engines 125

4.5.1 Nitrogen Oxides Nox 125

4.5.2 So2 126

4.5.3 CO and CO2 126

4.5.4 Aerosols 127

4.5.5 Volatile Organic Compounds VOC 128

4.5.6 Thermal Pollution 129

4.5.7 Regulations 129

4.6 The Private Car 129

4.6.1 Power Needs 130

4.6.2 Automobile Fuels 131

4.6.3 Three-Way Catalytic Converter 132

4.6.4 Electric Car 133

4.6.5 Hybrid Car 134

4.7 Economics of Energy Conversion 134

4.7.1 Capital Costs 134

4.7.2 Learning Curve 138

Exercises 138

References 142

5 Renewable Energy 145

5.1 Electricity from the Sun 146

5.1.1 Varying Solar Input 146

5.1.2 Electricity from Solar Heat: Concentrating Solar Power CSP 150

5.1.3 Direct Conversion of Light into Electricity: Photovoltaics PV 152

5.2 Energy from the Wind 159

5.2.1 Betz Limit 160

5.2.2 Aerodynamics 162

5.2.3 Wind Farms 165

5.2.4 Vertical Wind Profile 165

5.2.5 Wind Statistics 167

5.2.6 State of the Art and Outlook 168

5.3 Energy from the Water 169

5.3.1 Power from Dams 169

5.3.2 Power from Flowing Rivers 170

5.3.3 Power from Waves 170

5.3.4 Power from the Tides 174

5.4 Bio Energy 175

5.4.1 Thermodynamics of Bio Energy 175

5.4.2 Stability 180

5.4.3 Solar Efficiency 180

5.4.4 Energy from Biomass 182

5.5 Physics of Photosynthesis 183

5.5.1 Basics of Photosynthesis 184

5.5.2 Light-Harvesting Antennas 185

5.5.3 Energy Transfer Mechanism 187

5.5.4 Charge Separation 190

5.5.5 Flexibility and Disorder 193

5.5.6 Photoprotection 193

5.5.7 Research Directions 195

5.6 Organic Photocells: the Grätzel Cell 196

5.6.1 The Principle 196

5.6.2 Efficiency 199

5.6.3 New Developments and the Future 202

5.6.4 Applications 203

5.7 Bio Solar Energy 203

5.7.1 Comparison of Biology and Technology 204

5.7.2 Legacy Biochemistry 207

5.7.3 Artificial Photosynthesis 209

5.7.4 Solar Fuels with Photosynthetic Microorganisms: Two Research Questions 213

5.7.5 Conclusion 213

Exercises 215

References 217

6 Nuclear Power 221

6.1 Nuclear Fission 222

6.1.1 Principles 222

6.1.2 Four Factor Formula 226

6.1.3 Reactor Equations 229

6.1.4 Stationary Reactor 231

6.1.5 Time Dependence of a Reactor 233

6.1.6 Reactor Safety 234

6.1.7 Nuclear Explosives 237

6.2 Nuclear Fusion 238

6.3 Radiation and Health 244

6.3.1 Definitions 244

6.3.2 Norms on Exposure to Radiation 245

6.3.3 Normal Use of Nuclear Power 247

6.3.4 Radiation from Nuclear Accidents 247

6.3.5 Health Aspects of Fusion 247

6.4 Managing the Fuel Cycle 248

6.4.1 Uranium Mines 249

6.4.2 Enrichment 249

6.4.3 Fuel Burnup 252

6.4.4 Reprocessing 252

6.4.5 Waste Management 253

6.4.6 Nonproliferation 256

6.5 Fourth Generation Nuclear Reactors 257

Exercises 258

References 259

7 Dispersion of Pollutants 261

7.1 Diffusion 262

7.1.1 Diffusion Equation 262

7.1.2 Point Source in Three Dimensions in Uniform Wind 267

7.1.3 Effect of Boundaries 269

7.2 Dispersion in Rivers 270

7.2.1 One-Dimensional Approximation 271

7.2.2 Influence of Turbulence 275

7.2.3 Example: A Calamity Model for the Rhine River 277

7.2.4 Continuous Point Emission 278

7.2.5 Two Numerical Examples 280

7.2.6 Improvements 281

7.2.7 Conclusion 282

7.3 Dispersion in Groundwater 282

7.3.1 Basic Definitions 283

7.3.2 Darcy’s Equations 286

7.3.3 Stationary Applications 290

7.3.4 Dupuit Approximation 295

7.3.5 Simple Flow in a Confined Aquifer 298

7.3.6 Time Dependence in a Confined Aquifer 301

7.3.7 Adsorption and Desorption of Pollutants 302

7.4 Mathematics of Fluid Dynamics 304

7.4.1 Stress Tensor 304

7.4.2 Equations of Motion 308

7.4.3 Newtonian Fluids 309

7.4.4 Navier-Stokes Equation 310

7.4.5 Reynolds Number 311

7.4.6 Turbulence 313

7.5 Gaussian Plumes in the Air 317

7.5.1 Statistical Analysis 319

7.5.2 Continuous Point Source 321

7.5.3 Gaussian Plume from a High Chimney 322

7.5.4 Empirical Determination of the Dispersion Coefficients 323

7.5.5 Semi-Empirical Determination of the Dispersion Parameters 324

7.5.6 Building a Chimney 325

7.6 Turbulent Jets and Plumes 326

7.6.1 Dimensional Analysis 328

7.6.2 Simple Jet 329

7.6.3 Simple Plume 331

Exercises 333

References 334

8 Monitoring with Light 337

8.1 Overview of Spectroscopy 337

8.1.1 Population of Energy Levels and Intensity of Absorption Lines 341

8.1.2 Transition Dipole Moment: Selection Rules 341

8.1.3 Linewidths 342

8.2 Atomic Spectra 345

8.2.1 One-Electron Atoms 345

8.2.2 Many-Electron Atoms 346

8.3 Molecular Spectra 347

8.3.1 Rotational Transitions 347

8.3.2 Vibrational Transitions 349

8.3.3 Electronic Transitions 353

8.4 Scattering 359

8.4.1 Raman Scattering 359

8.4.2 Resonance Raman Scattering 360

8.4.3 Rayleigh Scattering 361

8.4.4 Mie Scattering 362

8.4.5 Scattering in the Atmosphere 362

8.5 Remote Sensing by Satellites 362

8.5.1 ENVISAT Satellite 362

8.5.2 SCIAMACHY’s Operation 362

8.5.3 Analysis 364

8.5.4 Ozone Results 368

8.6 Remote Sensing by Lidar 368

8.6.1 Lidar Equation and DIAL 369

8.6.2 Range-Resolved Cloud and Aerosol Optical Properties 371

Exercises 376

References 377

9 The Context of Society 379

9.1 Using Energy Resources 380

9.1.1 Energy Consumption 380

9.1.2 Energy Consumption and Resources 382

9.1.3 Energy Efficiency 383

9.1.4 Comparing Energy Resources 384

9.1.5 Energy Options 387

9.1.6 Conclusion 388

9.2 Fresh Water 389

9.3 Risks 389

9.3.1 Small Concentrations of Harmful Chemicals 390

9.3.2 Acceptable Risks 392

9.3.3 Small Probability for a Large Harm 393

9.3.4 Dealing with Uncertainties 394

9.4 International Efforts 396

9.4.1 Protection of the Ozone Layer 396

9.4.2 Protection of Climate 396

9.5 Global Environmental Management 398

9.5.1 Self-Organized Criticality 398

9.5.2 Conclusion 401

9.6 Science and Society 401

9.6.1 Nature of Science 401

9.6.2 Control of Science 402

9.6.3 Aims of Science 402

9.6.4 A New Social Contract between Science and Society 404

Exercises and social questions 405

Social questions 405

References 406
Appendix A: Physical and Numerical Constants 409
Appendix B: Vector Algebra 411
Appendix C: Gauss, Delta and Error Functions 419
Appendix D: Experiments in a Student’s Lab 423
Appendix E: Web Sites 425
Appendix F: Omitted Parts of the Second Edition 427
Index 429