Physics of Auroral Arc Formation

Physics of Auroral Arc Formation......Page 1
Geophysical Monograph Series......Page 3
Physics ofAuroral Arc Formation......Page 5
CONTENTS......Page 7
PREFACE......Page 10
Introduction......Page 11
2. General Morphology of Auroral Arcs......Page 12
3. Open Magnetosphere, the Auroral Ovaland the Inverted V Structure......Page 15
4. Electron Precipitation and the Field-Aligned Currents......Page 17
6. Causes of the Auroral Potential Structures......Page 20
References......Page 23
Introduction......Page 25
Auroral Bulges......Page 27
Evening Arcs......Page 29
Location of Discrete Features withRespect to the Diffuse Aurora......Page 30
Summary......Page 32
References......Page 33
Eastward auroral ?motion in the evening hour sector......Page 34
Electron precipitation and corresponding aurora......Page 35
Discussion......Page 37
Referencences......Page 40
Classification of Deformation Modes......Page 41
Shear propagation of peeled off ends......Page 42
Flickering......Page 43
Formation of complex striations......Page 44
Category 3......Page 46
Equatorward pr.opagation wave......Page 47
Distribution of the modes......Page 48
Conclusion and Discussion......Page 49
References......Page 51
Introduction......Page 52
Vorticity......Page 53
Boundary conditions and mapping......Page 54
Observations......Page 57
References......Page 58
The Basic Concepts......Page 60
The Observational Aspects......Page 62
Discussion and Conclusion......Page 64
References......Page 65
Inverted V Precipit. a?ion......Page 66
Ion Precipitation......Page 67
Field-Aligned Precipitation......Page 68
Low Energy Electron Precipitation......Page 69
DFI Downward Flowing Ions......Page 71
Counterstreaming Electron Beams......Page 72
Region 3......Page 73
References......Page 74
Evening Oval Arcs......Page 77
Discrete Arcs at Other Locations......Page 82
Conclusions and Discussions......Page 86
References......Page 88
Instrumentation......Page 90
New Work......Page 96
Parallel Electric Field Mechanisms......Page 97
Electrostatic Shock......Page 98
References......Page 99
Introduction......Page 101
Field Aligned Electrons Over Wide Energy Ranges......Page 103
High Altitude Inverted V Structures......Page 104
Summaarnyd D iscussion......Page 109
References......Page 111
ROCKET STUDIES OF PARTICLE STRUCTURE ASSOCIATED WITH AURORAL ARCS......Page 113
Examples of Upward Flowing Ion Events......Page 122
Relationship to Parallel Electric Fields......Page 123
Statistical Studies......Page 128
Summary and Conclusions......Page 129
Acknowledgements......Page 130
References......Page 131
Introduction......Page 132
Observations......Page 133
References......Page 137
Introduction......Page 139
X-ray Images......Page 140
Discussion......Page 142
Conclusions......Page 143
References......Page 144
THE LOW ALTITUDE ELECTRIC FIELD STRUCTURE OFDISCRETE AURORAL ARCS......Page 146
References......Page 152
The Boundary of the Polar Cap and its Relation to Electric Fields,Field-Aligned Currents, and Auroral Particle Precipitation......Page 153
Instruments......Page 154
Polar Cap As Defined By Electric Fields and Particles......Page 155
Field-Aligned Current Correlations......Page 156
Explanation of Gradients......Page 161
References......Page 162
Instrumentation......Page 164
Observations......Page 165
Discussion......Page 169
References......Page 172
Introduction......Page 174
A. Discrete Arcs in the Polar Cap......Page 175
B. Field-Aligned Currents near two Small-ScaleShock-like Structures......Page 178
i Dawnside Structures......Page 179
Summary and Discussion......Page 180
References......Page 182
Injection Boundaries......Page 183
References......Page 184
High Electric Fields Near and Perpendicular toAuroral Forms......Page 185
V-Shaped Electric Potential Structures AboveAuroral Forms......Page 187
Fine Structure in Auroral Electric Fields.......Page 192
References......Page 194
Radar Observations......Page 195
Measurements of Ionization and Conductivity......Page 196
Electric Field Measurements......Page 198
Summary......Page 199
References......Page 200
Discrete and Diffuse Auroras......Page 202
The Harang Discontinuity......Page 204
conclusion......Page 205
References......Page 206
Experimental Concept......Page 209
Experiment......Page 210
Results......Page 212
References......Page 215
1. Introduction......Page 216
2.1 Perfect Coupling State E ? O......Page 217
2.2 Imperfect Coupling State Ell ? 0......Page 219
3.1 Elementary Processes Supporting Parallel Electric Fields......Page 220
3.2 Distinction Between Double Layers and Electrostatic Shocks......Page 221
3.3 Auroral Acceleration Process......Page 222
References......Page 224
Wall Effects......Page 228
Particle and momentum flow......Page 229
Comparisons with Auroral Double Layers......Page 230
Critical electron drift velocity......Page 231
Wave-emissions......Page 232
Potential distribution......Page 233
Summary......Page 234
References......Page 235
Experimental Setup......Page 236
Sheath vs Double Layer......Page 237
Parameter Dependence......Page 238
Two-Dimensional Potential Profiles......Page 239
Distribut ion Functions......Page 240
Physical Model......Page 242
References......Page 243
Introduction......Page 244
Theoretical Interpretations......Page 245
Particle Anisotropy and Mirror Forces......Page 249
Towards a Unified Model of the Quiet Arc......Page 250
Conclusions and Prospects......Page 252
References......Page 253
II. Auroral Double Layer Criterion......Page 255
III Potential Drop Along Auroral Field Lines......Page 256
IV. The Relationship Between Field-AlignedCurrent and Potential Drop......Page 257
V. Imperfect Magnetosphere-IonosphereCoupling and Two-Dimensional AuroralDouble Layer......Page 258
References......Page 260
Relation Between jii and Vii......Page 262
Large-scale "Inverted-V" PrecipitationRegions Lyons, 1980......Page 264
Smaller Scale Discrete Auroral StructureLyons, 1980b......Page 266
Conclusion......Page 268
Time Stationary Analytic Double Layers......Page 270
Double Layer Simulations......Page 271
Magnetized Structures......Page 272
Discussion......Page 273
Conclusions......Page 274
References......Page 275
Introduction......Page 276
DISCUSSION......Page 278
References......Page 279
Models......Page 280
Simulation of Instabilities Associated with the Diffuse Aurora......Page 284
The Saturation and Heating Mechanism......Page 289
References......Page 292
ANOMALOUS DIFFUSION AND ION HEATING IN THE PRESENCE OF ELECTROSTATIC......Page 293
References......Page 297
1. Introduction......Page 298
2. Two-dimensional E x B turbulence......Page 299
3. Generation of Turbulence on a Kinetic Scale......Page 301
4. Summary and Conclusions......Page 303
References......Page 304
Ion-Acoustic Turbulence......Page 306
Buneman Instability......Page 307
Ion-Cyclotron Waves......Page 308
Double Layers......Page 309
Resistivity......Page 312
References......Page 313
Introduction......Page 314
V-Potential Structure......Page 315
Simulation Results......Page 318
Auroral Arc Deformations......Page 321
The Model......Page 322
The Simulation......Page 325
References......Page 329
Physical Picture of the Feedback Instability......Page 331
Governing Equations......Page 333
Model and Stationary Stateof the Auroral Oval......Page 336
Electrodynamic Property Associatedwith Auroral Arcs......Page 338
Appendix A......Page 341
References......Page 342
Periodic System......Page 343
Nonperiodic System......Page 345
References......Page 346
Results......Page 347
Discussion......Page 349
References......Page 350
Upper and Lower Cutoff Frequencies......Page 351
Fine Structure......Page 356
Conclusion......Page 359
References......Page 360
Plasma Waves on Auroral Field Lines......Page 361
References......Page 368
OBSERVATIONS PERTAINING TO THE GENERATION OF AURORALKILOMETRIC RADIATION......Page 369
Introduction......Page 379
ISIS 1 Ionogram Observations......Page 380
Correlated ISIS 1 Wave/Particle observations......Page 384
Correlated ISIS 1 Wave/Wave Observations......Page 387
References......Page 388
LABORATORY STUDY ON ION CYCLOTRON WAVES AND THEIR RELATION TO AURORAL ARCS......Page 390
References......Page 396
OBSERVATOIOFNE L ECTROMAGRNAEDTIICA TIOANT 2p......Page 397
References......Page 402
II. Microwave Scattering......Page 403
III. Spectral Measurements......Page 405
References......Page 407
Introduction......Page 408
Experimental Results......Page 410
Plasma Dynamics......Page 411
Electric Fields, Currents and Resistivity......Page 413
Energy Flow......Page 415
References......Page 416
Introduction......Page 418
Weak Turbulence, Nonlinear Theories AndMarginal Stability......Page 420
Anomalous Resistivity And Heating RatesFor Various Instabilities......Page 423
References......Page 425
I. Introduction......Page 428
1. Ext ended Double LaMer......Page 429
2. Cyclotron Maser Instability......Page 430
3. Distribution Function of Reflected Electrons......Page 431
III. Further Theoretical Considerations......Page 432
1. Quasilinear Saturation of AKR......Page 433
2. Limit of Zero Secondary Electrons......Page 434
References......Page 436
Theoretical Method......Page 438
Wave Mode Characteristics......Page 439
Predictions of Power Spectra......Page 442
Electromagnetic Waves......Page 444
References......Page 445
Small-Amplitude Fluid Analysis......Page 447
Time-Stationary Wave Properties......Page 449
Fast Mode......Page 450
References......Page 452
Transverse ion acceleration......Page 454
Effects of microscopic turbulenceon kinetic Alfv6n waves......Page 457
Discussion......Page 458
References......Page 459
The Propagation of a Shear Alfven Wave Packet......Page 461
Summary and Discussion......Page 463
References......Page 465
Introduction......Page 466
Formulation of the Problem......Page 468
Wave-Particle Diffusion......Page 471
The Limit of Strong Parallel and Perpendicular Diffusion......Page 472
References......Page 474