Contents

PREFACE xiii

1. INTRODUCTION 1

1.1 Summary 1

1.2 Definition of Space Weather 2

1.3 An Historical Perspective 3

1.4 The Advent of Space Weather Programs 20

1.5 Categories of Radio Systems 21

1.6 Other Influences on Systems 22

1.7 Space Weather Data Utilization 23

1.7.1 Availability of Space Weather Data 23

1.7.2 Operational Terminals & Workstations 24

1.8 Conclusions 24

1.9 References 25

1.10 Bibliography 27

2. THE ORIGINS OF SPACE WEATHER 29

2.1 Introduction 29

2.2 The Sun and its Influence 31

2.2.1 Solar Structure and Irradiance Properties 31

2.2.2 On the Nature of Solar Activity and Sunspots 36

2.2.3 Active Regions, Coronal Holes, and Solar Wind 39

2.2.4 The Canonical Sunspot Cycle 42

2.2.5 Prediction of the Sunspot Cycle 43

2.2.6 Solar Variability 45

2.2.7 Solar Flares 50

2.2.8 Storms and Declining Solar Activity 51

2.3 Magnetosphere and Geomagnetic Storms 54

2.3.1 The Geomagnetic Field 55

2.3.2 Magnetospheric Topology 60

2.3.3 Geomagnetic Activity Indices 62

2.3.5 Real-Time Geomagnetic Data 64

2.3.6 Magnetic Storms and the Ionosphere 65

2.3.7 The Halloween Storm Period of 2003 73

2.4 Motivation for Space Weather Observations 76

2.5 References 78

3. THE IONOSPHERE 81

3.1 Introduction 81

3.2 General Properties of the Ionosphere 82

3.2.1 Basic Structure 82

3.2.2 Formation of the Ionosphere 84

3.2.3 Ionospheric Layering 87

3.2.4 Chapman Layer Theory 90

3.3 Equilibrium Processes 92

3.4 Description of the Ionospheric Layers 95

3.4.1 Sounder Measurement Method 95

3.4.2 The D-Region 97

3.4.3 The E-Region 98

3.4.4 The F1-Region 101

3.4.5 The F2-Region 103

3.4.6 Anomalous Features of the F-Region 104

3.4.6.1 Diurnal Anomaly 105

3.4.6.2 Appleton Anomaly 105

3.4.6.3 December Anomaly 106

3.4.6.4 Winter (Seasonal) Anomaly 106

3.4.6.5 F-Region High-Latitude Trough 106

3.4.7 Irregularities in the Ionosphere 106

3.5 Diurnal Behavior of the Ionospheric Layers 108

3.5.1 Mean Variations 108

3.5.2 Short-Term Variations 108

3.6 Long-Term Solar Activity Dependence 112

3.7 Sporadic-E 114

3.7.1 General Characteristics 114

3.7.2 Formation of Midlatitude Sporadic E 114

3.7.3 Sporadic E at Non-temperate Latitudes 116

3.8 The High Latitude Ionosphere 116

3.8.1 Description of Plasma Blobs and Patches 120

3.8.2 Arctic Radio Propagation 122

3.8.3 Early Diagnostic Studies 122

3.8.4 Recent Diagnostic Studies 124

3.9 Ionospheric Response to Solar Flares 127

3.10 The Ionospheric Storm 129

3.10.1 Early Attempts at Storm Modeling 130

3.10.2 The NOAA-SEC STORM Model 132

3.10.3 Storm Studies Using NTS-2 Navigation Signals 134

3.10.4 The Halloween 2003 Storm 137

3.11 Ionospheric Current Systems 141

3.12 Ionospheric Models 141

3.12.1 Data Assimilation and Kalman Filters 146

3.12.2 GAIM 148

3.12.3 European Union COST Action Models 149

3.12.3.1 COST Action 238 150

3.12.3.2 COST Action 251 150

3.12.3.3 ESA Space Weather Working Team 152 3.12.4 Ionospheric Modeling Panel at IES2002 153

3.12.4.1 User Needs 154

3.12.4.2 Storm Modeling 154

3.12.4.3 Observations & Data Issues 155

3.12.4.4 Empirical Models 155

3.12.4.5 Data Sources for Modeling 156

3.12.4.6 Future of Ionospheric Modeling 156

3.12.4.7 Data Assimilation Modeling 157

3.12.4.8 Solar EUV Modeling 157

3.12.4.9 WBMOD Overview 157

3.12.4.10 Weather Model for Scintillation 157

3.12.4.11 Panel Discussion Synopsis 158

3.12.4.12 Panel Conclusions 161

3.13 Ionospheric Predictions 161

3.14 Science Issues and Challenges 163

3.15 References 164 4. TELECOMMUNICATION SYSTEMS 175

4.1 Introduction 175

4.2 Outline of Ionospheric Effects 178

4.3 Terrestrial Telecommunications 181

4.3.1 Longwave Propagation 181

4.3.2 Extremely Low Frequency 183

4.3.3 Very Low Frequency and Low Frequency 184

4.3.4 Medium Frequency 185

4.3.5 High Frequency (shortwave) 187

4.3.5.1 Operational HF Systems 193

4.3.5.2 System Performance Modeling 196

4.4 Earth-Space Telecommunications 198

4.4.1 Integrated Propagation Effects 198

4.4.1.1 Refraction 199

4.4.1.2 Phase and Group Path Variation 202

4.4.1.3 Ionospheric Doppler Shift 206

4.4.1.4 Faraday Rotation 206

4.4.1.5 Time Dispersion 209

4.4.1.6 Absorption 209

4.4.1.7 Comments on Total Electron Content 210

4.4.2 Differential Effects and the Ne Distribution 213

4.4.2.1 Diurnal Variation of Scintillation 214

4.4.2.2 Global Morphplogy of Scintillation 216

4.4.2.3 Modeling of the Scintillation Channel 219

4.4.2.4 Mitigation Schemes 220

4.5 Space Weather Support for Systems 221

4.5.1 Military C3I Requirements 221

4.5.2 Systems Combating Space Weather 223

4.5.2.1 GLOBALink/HF 225

4.5.2.2 FAA WAAS System 237

4.5.3 Practical Approaches 240

4.5.4 Benefits of Space Weather Information 243

4.6 References 246

5. PREDICTION SERVICES & SYSTEMS 255

5.1 Introduction 255

5.2 Requirements 257

5.3 Elements of the Prediction Process 258

5.4 Organizational Approaches 260

5.4.1 Forecasting Services 260

5.4.2 International Space Environment Service 263

5.4.3 NOAA 265

5.4.3.1 Space Environment Center 265

5.4.3.2 National Geophysical Data Center 283

5.4.4 RWC Canada (NRCan) 285

5.4.5 RWC Australia 287

5.4.6 Jet Propulsion Laboratory 289

5.4.7 Rutherford Appleton Laboratory 293

5.4.8 Institute of Communications and Navigation 293

5.4.9 RWC Warsaw and IDCE 295

5.4.10 RWC Brussels and SIDC 296

5.4.11 Military Systems 296

5.4.11.1 Air Force Weather Agency 296

5.4.12 Special Product: Email Alerts 298

5.5 Commercial Forecasting Services 298

5.5.1 Vendor Industry 299

5.5.1.1 Northwest Research Associates 299

5.5.1.2 Radio Propagation Services 301

5.5.1.3 Solar Terrestrial Dispatch 302

5.6 Systems for Forecasting 302

5.6.1 OPSEND 303

5.6.2 SCINDA 304

5.7 Concluding Remark 305

5.8 References 306

6. RESEARCH ACTIVITIES & PROGRAMS 309

6.1 Introduction 309

6.2 National Space Weather Program 311

6.3 Living with a Star 315

6.4 Data Assimilation and Transfer 317

6.5 Military Space Weather Involvement 3j7

6.5.1 Early DoD Activity 317

6.5.2 Space Weather Architecture 313

6.5.3 Existing Capabilities 319

6.5.4 Areas for Improvement 320

6.5.5 Space Weather Architecture "Vector" 323

6.6 International Initiatives 324

6.6.1 European Union COST Actions 325

6.6.1.1 COST Action 238 325

6.6.1.2 COST Action 251 325

6.6.1.3 COST Action 271 326

6.6.1.4 COST Action 724 326

6.6.2 European Space Agency 327

6.6.3 Sweden 327

6.6.4 France 328

6.6.5 Japan 328

6.6.6 Canada 329

6.6.7 Australia 329

6.7 Scientific & Professional Organizations 329

6.7.1 URSI 329

6.7.2 COSPAR 330

6.7.3 SCOSTEP 331

6.7.5 NCEP 332

6.7.6 CSWIG 332

6.7.7 Space Weather Week 333

6.8 Research Programs & Activities 334

6.8.1 CEDAR 334

6.8.3 SHINE 336

6.8.4 CISM 336

6.8.5 CAWSES 337

6.8.6 Additional Missions & Activities 337

6.9 Agencies, Institutions & Companies 341

6.10 Comment on Internet Resources 344

6.11 References 345 7. EPILOGUE 347

- Featuring an interview with the Director of SEC

ACRONYMS & TERMS 355

INDEX 367

About the Author 381

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