Preface ........................................................ XI
Acknowledgements ............................................... XV
1 Stormy Tour from the Sun to the Earth ........................ 1
1.1 Source of Space Storms: the Sun ......................... 1
1.1.1 The Sun as a star ................................ 2
1.1.2 Solar spectrum ................................... 5
1.1.3 Solar atmosphere ................................. 7
1.1.4 Rotation of the Sun .............................. 8
1.1.5 Sunspots and solar magnetism .................... 11
1.1.6 Coronal activity ................................ 16
1.2 The Carrier to the Earth: the Solar Wind ............... 21
1.2.1 Elements of solar wind expansion ................ 21
1.2.2 The interplanetary magnetic field ............... 25
1.2.3 The observed structure of the solar wind ........ 28
1.2.4 Perturbed solar wind ............................ 29
1.3 The Magnetosphere ...................................... 32
1.3.1 Formation of the Earth's magnetosphere .......... 32
1.3.2 The outer magnetosphere ......................... 34
1.3.3 The inner magnetosphere ......................... 37
1.3.4 Magnetospheric convection ....................... 40
1.3.5 Origins of magnetospheric plasma ................ 44
1.3.6 Convection and electric fields .................. 45
1.4 The Upper Atmosphere and the Ionosphere ................ 48
1.4.1 The thermosphere and the exosphere .............. 49
1.4.2 Structure of the ionosphere ..................... 50
1.4.3 Electric currents in the polar ionosphere ....... 51
1.5 Space Storms Seen from the Ground ...................... 54
1.5.1 Measuring the strength of space storms .......... 55
1.5.2 Geomagnetically induced currents ................ 57
2 Physical Foundations ........................................ 59
2.1 What is Plasma? ........................................ 59
2.1.1 Debye shielding ................................. 60
2.1.2 Plasma oscillations ............................. 61
2.1.3 Gyro motion ..................................... 62
2.1.4 Collisions ...................................... 63
2.2 Basic Electrodynamics .................................. 64
2.2.1 Maxwell's equations ............................. 64
2.2.2 Lorentz force ................................... 66
2.2.3 Potentials ...................................... 66
2.2.4 Energy conservation ............................. 70
2.2.5 Charged particles in electromagnetic fields ..... 71
2.3 Tools of Statistical Physics ........................... 73
2.3.1 Plasma in thermal equilibrium ................... 73
2.3.2 Derivation of Vlasov and Boltzmann equations .... 75
2.3.3 Macroscopic variables ........................... 78
2.3.4 Derivation of macroscopic equations ............. 80
2.3.5 Equations of magnetohydrodynamics ............... 82
2.3.6 Double adiabatic theory ......................... 86
3 Single Particle Motion ...................................... 89
3.1 Magnetic Drifts ........................................ 89
3.2 Adiabatic Invariants ................................... 93
3.2.1 The first adiabatic invariant ................... 93
3.2.2 Magnetic mirror and magnetic bottle ............. 95
3.2.3 The second adiabatic invariant .................. 96
3.2.4 Betatron and Fermi acceleration ................. 96
3.2.5 The third adiabatic invariant ................... 97
3.3 Motion in the Dipole Field ............................. 98
3.4 Motion Near a Current Sheet ........................... 103
3.4.1 The Harris model ............................... 104
3.4.2 Neutral sheet with a constant electric field ... 106
3.4.3 Current sheet with a small perpendicular
magnetic field component ....................... 107
3.5 Motion in a Time-dependent Electric Field ............. 108
3.5.1 Slow time variations ........................... 108
3.5.2 Time variations in resonance with gyro
motion ......................................... 108
3.5.3 High-frequency fields .......................... 109
4 Waves in Cold Plasma Approximation ......................... 113
4.1 Basic Concepts ........................................ 113
4.1.1 Waves in linear media .......................... 113
4.1.2 Wave polarization .............................. 117
4.1.3 Reflection and refraction ...................... 118
4.2 Radio Wave Propagation in the Ionosphere .............. 121
4.2.1 Isotropic, lossless ionosphere ............... 121
4.2.2 Weakly inhomogeneous ionosphere ................ 124
4.2.3 Inclusion of collisions ........................ 128
4.2.4 Inclusion of the magnetic field ................ 129
4.3 General Treatment of Cold Plasma Waves ................ 130
4.3.1 Dispersion equation for cold plasma waves ...... 130
4.3.2 Parallel propagation (θ = 0) ................... 133
4.3.3 Perpendicular propagation (θ = Π/2) ............ 136
4.3.4 Propagation at arbitrary angles ................ 137
5 Vlasov Theory .............................................. 141
5.1 Properties of the Vlasov Equation ..................... 141
5.2 Landau's Solution ..................................... 143
5.3 Normal Modes in a Maxwellian Plasma ................... 148
5.3.1 The plasma dispersion function ................. 148
5.3.2 The Langmuir wave .............................. 149
5.3.3 The ion-acoustic wave .......................... 150
5.3.4 Macroscopic derivation of Langmuir and
ion-acoustic modes ............................. 151
5.4 Physics of Landau Damping ............................. 153
5.5 Vlasov Theory in a General Equilibrium ................ 155
5.6 Uniformly Magnetized Plasma ........................... 157
5.6.1 Perpendicular propagation (θ = Π/2) ............ 159
5.6.2 Parallel propagation (θ = 0) ................... 161
5.6.3 Propagation at arbitrary angles ................ 161
6 Magnetohydrodynamics ....................................... 163
6.1 From Hydrodynamics to Conservative MHD Equations ...... 163
6.2 Convection and Diffusion .............................. 166
6.3 Frozen-in Field Lines ................................. 168
6.4 Magnetohydrostatic Equilibrium ........................ 171
6.5 Field-aligned Currents ................................ 173
6.5.1 Force-free fields .............................. 173
6.5.2 Grad-Shafranov equation ........................ 176
6.5.3 General properties of force-free fields ........ 177
6.5.4 FACs and the magnetosphere-ionosphere
coupling ....................................... 178
6.5.5 Magnetic helicity .............................. 180
6.6 Alfvén Waves .......................................... 183
6.6.1 Dispersion equation of MHD waves ............... 183
6.6.2 MHD wave modes ................................. 184
6.7 Beyond MHD ............................................ 186
6.7.1 Quasi-neutral hybrid approach .................. 187
6.7.2 Kinetic Alfven waves ........................... 189
7 Space Plasma Instabilities ................................. 191
7.1 Beam-plasma Modes ..................................... 192
7.1.1 Two-stream instability ......................... 193
7.1.2 Buneman instability ............................ 195
7.2 Macroinstabilities .................................... 196
7.2.1 Rayleigh-Taylor instability .................... 196
7.2.2 Farley-Buneman instability ..................... 199
7.2.3 Ballooning instability ......................... 200
7.2.4 Kelvin-Helmholtz instability ................... 202
7.2.5 Firehose and mirror instabilities .............. 204
7.2.6 Flux tube instabilities ........................ 206
7.3 Microinstabilities .................................... 207
7.3.1 Monotonically decreasing distribution
function ....................................... 207
7.3.2 Multiple-peaked distributions .................. 208
7.3.3 Ion-acoustic instability ....................... 210
7.3.4 Electrostatic ion cyclotron instability ........ 212
7.3.5 Current-driven instabilities perpendicular
to В ........................................... 213
7.3.6 Electromagnetic cyclotron instabilities ........ 215
7.3.7 Ion beam instabilities ......................... 217
8 Magnetic Reconnection ...................................... 219
8.1 Basics of Reconnection ................................ 219
8.1.1 Classical MHD description of reconnection ...... 220
8.1.2 The Sweet-Parker model ......................... 221
8.1.3 The Petschek model ............................. 223
8.1.4 Asymmetric reconnection ........................ 225
8.2 Collisionless Reconnection ............................ 227
8.2.1 The tearing mode ............................... 228
8.2.2 The collisionless tearing mode ................. 229
8.2.3 Tearing mode or something else? ................ 231
8.2.4 The Hall effect ................................ 232
8.3 Reconnection and Dynamo ............................... 236
8.3.1 Current generation at the magnetospheric
boundary ....................................... 236
8.3.2 Elements of solar dynamo theory ................ 238
8.3.3 The kinematic αω dynamo ........................ 241
9 Plasma Radiation and Scattering ............................ 245
9.1 Simple Antennas ....................................... 245
9.2 Radiation of a Moving Charge .......................... 248
9.3 Bremsstrahlung ........................................ 251
9.4 Cyclotron and Synchrotron Radiation ................... 255
9.5 Scattering from Plasma Fluctuations ................... 258
9.6 Thomson Scattering .................................... 261
10 Transport and Diffusion in Space Plasmas ................... 267
10.1 Particle Flux and Phase Space Density ................. 267
10.2 Coordinates for Particle Flux Description ............. 269
10.3 Elements of Fokker-Planck Theory ...................... 271
10.4 Quasi-Linear Diffusion Through Wave-Particle
Interaction ........................................... 273
10.5 Kinetic Equation with Fokker-Planck Terms ............. 276
11 Shocks and Shock Acceleration .............................. 279
11.1 Basic Shock Formation ................................. 280
11.1.1 Steepening of continuous structures ............ 280
11.1.2 Hydrodynamic shocks ............................ 282
11.2 Shocks in MHD ......................................... 283
11.2.1 Perpendicular shocks ........................... 283
11.2.2 Oblique shocks ................................. 285
11.2.3 Rotational and tangential discontinuities ...... 287
11.2.4 Thickness of the shock front ................... 288
11.2.5 Collisionless shock wave structure ............. 290
11.3 Particle Acceleration in Shock Waves .................. 293
11.3.1 Shock drift acceleration ....................... 294
11.3.2 Diffusive shock acceleration ................... 295
11.3.3 Shock surfing acceleration ..................... 297
12 Storms on the Sun .......................................... 299
12.1 Prominences and Coronal Loops ......................... 300
12.2 Radio Storms on the Sun .............................. 302
12.2.1 Classification of radio emissions .............. 303
12.2.2 Physical mechanisms for solar radio
emissions ...................................... 304
12.3 Solar Flares .......................................... 307
12.3.1 Observational characteristics of solar
flares ......................................... 307
12.3.2 Physics of solar flares ........................ 311
12.4 Coronal Mass Ejections ................................ 314
12.4.1 CMEs near the Sun .............................. 315
12.4.2 Propagation time to 1 AU ...................... 317
12.4.3 Magnetic structure of ICMEs .................... 318
12.5 CMEs, Flares and Particle Acceleration ................ 320
13 Magnetospheric Storms and Substorms ........................ 323
13.1 What are Magnetic Storms and Substorms? ............... 323
13.1.1 Storm basics ................................... 324
13.1.2 The concept of substorm ........................ 326
13.1.3 Observational signatures of substorms .......... 326
13.2 Physics of Substorm Onset ............................. 333
13.2.1 The outside-in view ............................ 334
13.2.2 The inside-out view ............................ 339
13.2.3 External triggering of substorm expansion ...... 342
13.2.4 Timing of substorm onset ....................... 342
13.3 Storm-Time Activity ................................... 345
13.3.1 Steady magnetospheric convection ............... 345
13.3.2 Substorm-like activations and sawtooth
Events ......................................... 348
13.4 ICME-Storm Relationships .............................. 350
13.4.1 Geoeffectivity of an ICME ...................... 350
13.4.2 Different response to different drivers ........ 352
13.5 Storms Driven by Fast Solar Wind ...................... 354
13.5.1 27-day recurrence of magnetospheric activity ... 354
13.5.2 Differences from ICME-driven storms ............ 355
13.6 Energy Budgets of Storms and Substorms ................ 357
13.6.1 Energy supply .................................. 357
13.6.2 Ring current energy ............................ 358
13.6.3 Ionospheric dissipation ........................ 360
13.6.4 Energy consumption farther in the
magnetosphere .................................. 362
13.6.5 Energy transfer across the magnetopause ........ 362
13.7 Superstorms and Polar Cap Potential Saturation ........ 365
13.7.1 Quantification of the saturation ............... 366
13.7.2 Hill-Siscoe formulation ........................ 366
13.7.3 The Alfven wing approach ....................... 368
13.7.4 Magnetosheath force balance .................... 369
14 Storms in the Inner Magnetosphere .......................... 371
14.1 Dynamics of the Ring Current .......................... 372
14.1.1 Asymmetric structure of the ring current ....... 372
14.1.2 Sources of the enhanced ring current ........... 373
14.1.3 Role of substorms in storm evolution ........... 376
14.1.4 Loss of ring current through charge exchange
collisions ..................................... 376
14.1.5 Pitch angle scattering by wave-particle
interactions ................................... 379
14.1.6 ENA imaging of the ring current ................ 381
14.2 Storm-Time Radiation Belts ............................ 382
14.2.1 Sources of radiation belt ions ................. 382
14.2.2 Losses of radiation belt ions .................. 383
14.2.3 Transport and acceleration of electrons ........ 384
14.2.4 Electron losses ................................ 390
15 Space Storms in the Atmosphere and on the Ground ........... 393
15.1 Coupling to the Neutral Atmosphere .................... 393
15.1.1 Heating of the thermosphere .................... 394
15.1.2 Solar proton events and the middle
atmosphere ..................................... 394
15.2 Coupling to the Surface of the Earth .................. 395
References .................................................... 399
Index ......................................................... 411
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