Heliophysical Processes (eBook)

Preface 5
Contents 7
List of Contributors 9
The Sun in the Universe 11
1 Introduction 11
2 Solar Flares 12
3 Effects of Solar Radiation 13
3.1 Solar Radiation Propulsion: Solar Sail 13
3.2 Solar Twins 14
4 Distance to Sun 14
5 Newton and the Density of the Sun 14
6 The Sun and Olber's Paradox 14
7 Discovery of Helium 15
8 Gold in the Sun 16
9 Cosmic Power Houses 16
10 Most Energetic Objects in the Universe 17
11 Nuclear Reactions in the Solar Core 17
12 Supernova Neutrinos 18
13 Sudbury Heavy Water Neutrino Detector (SNO) 19
14 Some Subtleties of Solar Nuclear Reactions 19
15 Search for Solar Axions 20
16 Axions and CAST 21
17 Why is the Sun Getting More Luminous? 21
18 Solar Evolution from ZAMS 21
18.1 Five Phases of Sun's Evolution 22
19 Fate of Other Stars 23
20 Concluding Remarks 23
References 24
Solar Interior 25
1 Introduction 25
2 Solar Modeling Procedure 25
2.1 Basic Equations of Solar Structure 26
2.2 Energy Production 27
2.3 Energy Transport Through the Solar Interior 28
3 Standard Solar Model 29
4 Solar Neutrinos 29
4.1 Non-Standard Solar Models 33
4.2 Origin of Neutrino Problem in Non-Solar Effects? 33
5 Solar Oscillations 34
5.1 Helioseismology: The Science of the Ringing Sun 35
5.2 Solar Global Modes of Oscillation 36
5.3 Trapping of the Modes 36
5.4 Solar Dispersion Relation: The l– Diagram 38
5.5 Observational Requirements and the Instruments 39
5.6 The Analysis Techniques 40
6 Inferences From the Global Helioseismic Data 40
6.1 Solar Radius, Density and Base of the Convection Zone 41
6.2 Solar Internal Rotation and the ``Tachocline'' 42
7 Local Helioseismology 43
8 Summary 43
References 43
Dynamo Processes 45
1 Introduction: Magnetic Fields in the Heliosphere 45
2 Magnetohydrodynamics: Basic Theoretical Ideas 46
2.1 Magnetic Reynolds Number 48
2.2 Magnetic Diffusion 49
2.3 Concept of Flux Freezing 49
2.4 Magnetic Buoyancy 50
3 Formulating of the Kinematic Mean-Field Dynamo Problem 51
3.1 Evolution Equations for the Poloidal and Toroidal Fields 53
3.2 Efficiency of the Dynamo Process: Dynamo Numbers 55
4 Application to the Sun: The Solar Dynamo 56
4.1 Solar Magnetic Fields 56
4.2 Large-Scale Solar Flows 57
4.3 Understanding the Solar Cycle 59
5 Concluding Remarks 61
References 62
Large-Scale Solar Eruptions 63
1 Introduction 63
2 A Large-Scale Eruption Illustrated 64
3 CME Properties 70
4 CMEs and Flares 71
5 CMEs, Shocks, Type II Bursts, and SEPs 74
6 CMEs and Geomagnetic Storms 77
6.1 Halo CMEs 77
6.2 Geoeffective CMEs 78
7 Summary 79
References 80
Solar Energetic Particles: Acceleration and Observations 82
1 What are Solar Energetic Particles? 82
2 Observations of SEPs 84
2.1 Proton Observations 84
2.2 Neutron Observations 85
2.3 Gamma-Ray Observations 86
3 Acceleration, Emission and Transport of SEPs 86
3.1 Acceleration of SEPs 86
3.2 Transport of SEPs 87
3.3 Emission of Neutral particles 88
4 Summary 88
References 90
The Solar Wind and Its Interaction with the Interstellar Medium 91
1 Introduction and Basic Concepts 91
2 History 93
3 Solar Wind Basics 94
4 Radial Evolution of the Solar Wind 97
5 Obstacles in the Solar Wind 99
References 104
Reconnection Process in the Sun and Heliosphere 107
1 Introduction 107
1.1 Basic Reconnection Process 109
2 Reconnection Models 112
2.1 Sweet–Parker Model 112
2.2 Petschek Model 114
2.3 Spontaneous Reconnection or Patchy Reconnection 116
2.4 Collisionless Tearing Mode 117
3 Role of Magnetic Reconnection in Solar Flares 118
3.1 Reconnection Between Emerging Flux and Coronal Field 122
3.2 Recent Simulation and Present Status of Theoretical Understanding 122
3.3 Scale-Matching Between Macro and the Micro Features or Scales 123
3.4 Turbulent Structure in the Magnetic Reconnection Jet 123
3.5 Reconnection in Heliospheric Current Sheet 124
4 Summary 125
References 125
MHD Fluctuations in the Heliosphere 127
1 Introduction 127
2 Alfvénic Fluctuations 129
3 Magnetic Variations 130
4 Turbulence in Low-Latitude Wind 133
5 Turbulence in Polar Wind 135
6 Solar Wind Turbulence Models 137
6.1 Models for Low-Latitude Turbulence 138
6.2 Models for Polar Turbulence 140
7 Final Remarks 142
References 143
Radio Emission Processes: Parts I and II 145
1 Introduction 145
2 Bremsstrahlung 145
3 Gyro-Emission 149
4 Synchrotron Emission 149
4.1 Synchrotron Spectrum 151
5 Summary 152
References 152
1 Plasma Emission 153
2 Electron Cyclotron Maser Emission 156
3 Summary 158
References 159
Elemental and Charge State Composition in the Heliosphere 160
1 Introduction: Why Composition and Q-State? 160
2 Key Composition Parameters 162
3 Techniques for Solar Wind and Suprathermals 163
3.1 Electrostatic Analyzers 163
3.2 Time-of-Flight Spectrometers 164
3.3 High-Resolution Time-of-Flight Spectrometers 165
4 Key Composition Observations in the Solar Wind 166
4.1 The FIP Effect 166
4.2 Isotope Fractionation 166
4.3 Implantation of Singly Charged Pickup Ions 167
5 Techniques for Composition of Energetic Ions 168
5.1 E– E Telescopes 168
5.2 Ionic Charge State Measurement at High Energies 170
6 Key Observations with Energetic Particles 171
6.1 Elemental and Isotopic Composition 171
6.1.1 Gradual SEPs 171
6.1.2 Impulsive SEPs 172
6.2 Ionic Charge States 173
6.2.1 Energy Dependence of Q 173
6.3 Sources and Fractionation in Interplanetary Space 174
7 Summary and Conclusions 175
References 176
Planetary Atmospheres 177
1 The Planets 177
2 Atmospheric Divisions in Terms of Temperature Structure 180
2.1 Troposphere 180
2.2 Stratosphere 181
2.3 Mesosphere 182
2.4 Thermosphere 182
2.5 Exosphere 183
3 Other Divisions 184
3.1 Ionosphere 184
3.2 Magnetosphere 184
4 Terrestrial Gravity 185
5 Hydrostatic (Barometric Equation) 185
6 Escape of Atmospheric Gases 186
7 Diffusion 188
8 Atmospheric Dynamics 192
8.1 Equations of Motion 193
8.2 Geostrophic Approximation 194
8.3 Cyclostrophic Motion 194
8.4 Equation of Continuity 194
8.5 Equation of State 195
8.6 General Circulation 195
8.7 Thermospheric Winds 195
9 Other Planetary Atmospheres 197
References 200
Planetary Ionospheres 201
1 Introduction 201
2 Ionospheric Structure 202
3 Conservation Laws 202
4 Theory of Photoionization 205
4.1 Simplified Production Function 205
4.2 Gracing Incidence and Generalized Production Function 206
4.3 Optical Depth and Ionization Potential 207
4.4 Chemical Loss of Ionization 209
4.5 Formation of Ionospheric Regions 209
4.6 Formation of F1 Layer 210
4.7 Plasma Diffusion and F2 Layer 210
4.7.1 Effect of Geomagnetic Field 211
4.7.2 F2 Layer 212
4.8 Effect of Neutral Wind and Electric Field 212
4.8.1 F3 Layer 213
5 Ionospheric Electric Fields and Currents 214
5.1 Dynamo Theory 214
5.1.1 Ion and Electron Velocities 214
5.2 Ionospheric Conductivities 215
5.2.1 Spatial Variation of Conductivity and Electrojets 217
6 Ionospheric Variations and Irregularities 218
References 219
Planetary Magnetospheres 220
1 Past 220
2 Present 221
2.1 Magnetization 223
2.2 Magnetosphere in 3D 224
2.3 Reconnexion 225
2.4 Turbulence and Acceleration 226
2.5 Rotation and Circulation 228
2.6 Magnetotail and Space Storms 229
3 Future 231
Further Reading 232
The Sun and Space Weather 237
1 Definition of Space Weather and Some Examples 237
1.1 Definition 237
1.2 Space Weather Customers 238
2 Some MHD Basics 239
2.1 The Lorentz Force 239
2.2 Charged Particles and Fields 239
2.3 Magnetic Mirror 240
2.4 Earth's Magnetic Field 240
3 Solar Energetic Phenomena 243
3.1 Active Regions 243
3.2 Flares and CMEs 244
3.3 Solar Wind and Interplanetary Magnetic Field 246
4 Solar Radiation and Particles 246
4.1 Solar Irradiance 246
4.2 Solar Energetic Radiation 247
4.3 Particles 247
4.4 Space Climate 248
5 Space Weather and Damage 249
5.1 Effects of Radiation on Biological Systems 249
5.2 Surface Charging 250
5.3 Solar Activity and Satellite Lifetimes 251
5.4 Some Examples of Space Weather Damage 251
5.5 Geomagnetically Induced Currents 252
References 253
Sun: Climate Coupling on Sub-Decadal to Multi-Millennial Time Scales 254
1 Introduction 254
2 Variable Sun 255
3 Solar Spectral Variability 257
4 Records of Past Solar Activity 258
4.1 14 C Record 259
4.1.1 Geomagnetic Influence on 14C Production 259
4.1.2 Effect of Climatic Variations on Transport and Storage of 14C 260
4.2 10Be Record 261
5 Sun and Terrestrial Climate Variations: Causal Mechanisms 262
6 Solar Influence on Monsoon 265
7 Conclusion 267
References 268
The Planetary X-ray Emission 273
1 Introduction 273
2 Processes of Planetary X-ray Production 275
3 Electron Collision: Line and Bremsstrahlung Emission 276
4 Solar Photon Scattering and Fluorescence from Planetary Atmospheres and Surfaces 277
5 Charge Exchange of Highly Ionized Heavy Solar Wind Ions 278
6 Charge Exchange and Direct Collisional Excitation of Very Energetic Heavy Ions 278
7 Summary 279
References 283