Ionospheric Sporadic (eBook)

Front Cover 1
Ionospheric Sporadic E 4
Copyright Page 5
Table of Contents 8
Dedication 6
Preface 10
Introductory Remarks 12
CHAPTER I 16
Chapter 1. The Occurrence of Sporadic E 18
1. INTRODUCTION 18
2. GEOGRAPHIC OCCURRENCE OF SPORADIC E 18
3. TEMPORAL VARIATIONS OF SPORADIC E 21
Chapter 2. Reflection Mechanisms for Sporadic E 28
1. THIN LAYER MODEL 28
2. SCATTERING MODEL 34
REFERENCES 41
Chapter 3. Final Remarks of 1957 AGARD Conference of Sporadic-E Ionization 43
1. THE FACTS 43
2. ELECTRON DISTRIBUTIONS 45
3. THE ULTIMATE CAUSES OF ES 46
4. FUTURE INVESTIGATIONS 47
CHAPTER II. Part A 50
Chapter 4. The Reflection Coefficient and Fading Characteristics of Signals Returned from the Es Layer at Ibadan 52
1. INTRODUCTION 52
2. THE PARTIAL REFLECTION COEFFICIENT FOR EQUATORIAL TYPE ES 53
3. FADING OF PARTIAL REFLECTIONS FROM EQUATORIAL TYPE ES 55
4. AMPLITUDE DISTRIBUTION 60
5. FADING CHARACTERISTICS OF ECHOES FROM BLANKETING TYPE ES 62
REFERENCES 64
Chapter 5. A Study of Radio Wave Scattering from Sporadic E near the Magnetic Equator 66
1. THE IGY EXPERIMENT 66
2. THE ASSOCIATION OF EQUATORIAL SPORADIC E WITH THE EQUATORIAL ELECTROJET 74
3. ON THE NATURE OF EQUATORIAL SPORADIC E 77
4. ON THE NATURE OF EQUATORIAL SLANT SPORADIC E 88
5. CONCLUSIONS 91
REFERENCES 92
Chapter 6. Sporadic E as Observed with Rockets 93
1. GRADIENTS 94
2. UNIFORMITY OF THE ES LAYER 94
3. HEIGHT PREFERENCE 98
4. GRADIENTS IN ELECTRON DENSITY 101
5. COMPARISON WITH THE PULSE TECHNIQUE 101
6. TIME VARIATION 102
REFERENCES 102
Chapter 7. Backscatter Observations of Sporadic E 104
1. INTRODUCTION 104
2. DEFINITION AND IDENTIFICATION 105
3. INTERPRETATION AND OBSERVATION LIMITATIONS 106
4. AURORAL ES 108
5. EQUATORIAL ES 111
6. TEMPERATE LATITUDE ES 114
7. DRIFTING ES 122
REFERENCES 123
Chapter 8. Sporadic E as Observed from Mayaguez, P. R. by Backscatter Sounders 125
1. INTRODUCTION 125
2. INSTRUMENTATION 125
3. METHOD OF OBSERVATION 125
4. SEASONAL AND DIURNAL VARIATIONS OF ES ACTIVITY 127
5. AZIMUTHAL VARIATION OF SPORADIC E 132
6. MOTION OF ES PATCHES 132
7. CONCLUSION 137
REFERENCES 137
Chapter 9. Report on Recent Es Work in Brisbane 138
1. INTRODUCTION 138
3. MAGNETIC CORRELATION (WILKIE) 141
4. FIELD-ALIGNED IONIZATION (GOODWIN) 144
5. PHASE-PATH TECHNIQUES (THOMAS) 144
6. AIRGLOW CORRELATION (DANZIGER) 144
7. CLOSED SPACED p'f 145
REFERENCES 145
Chapter 10. Recent Sporadic-E Experimental Work in the United States 146
1. INTRODUCTION 146
2. OBSERVATIONS OF ES AT OBLIQUE INCIDENCE AND WITH A MIDPOINT IONOSONDE 147
3. FADING RATE 153
4. MULTIPLE PATH STUDY 154
5. CONCLUSIONS 155
REFERENCES 157
Chapter 11. Sporadic-E Propagation with 3 µsec Pulses 158
REFERENCE 163
CHAPTER II Part B 164
Chapter 12. Definitions of Frequency Parameters of Es-Layers and their Accuracy 166
1. GENERAL CONSIDERATIONS 166
2. SYSTEMATIC DEFINITIONS 167
3. APPLICATION TO ES-LAYERS 169
4. DISTINCTION OF THE MAGNETO-IONIC COMPONENTS 171
5. DETAILED INSTRUCTIONS FOR DISTINGUISHING BETWEEN THE MAGNETO-IONIC COMPONENTS 171
CONCLUSION 180
REFERENCES 180
Chapter 13. The Occurrence of Sporadic E during the IGY 181
I. INTRODUCTION 181
2. GEOGRAPHICAL OCCURRENCE OF TOTAL SPORADIC E 181
3. VARIATION WITH SUNSPOT CYCLE 186
4. TYPES OF ES 186
Chapter 14. A Note on the Heights of the Different IGY Types of ES 193
REFERENCE 196
Chapter 15. Variations in Frequency of Occurrence of Sporadic E, 1949-1959 197
1. INTRODUCTION 197
2. UNIFORMITY OF DATA 198
3. CONVENTIONS USED IN OBTAINING CORRELATION COEFFICIENTS 199
4. ESTIMATION OF SUNSPOT NUMBERS FOR THE LATTER HALF OF 1959 200
6. DIURNAL, SEASONAL AND YEARLY CORRELATION COEFFICIENTS 205
7. DISCUSSION OF RESULTS: CONCLUSIONS 206
REFERENCES 208
Chapter 16. Lunar Tidal Variations of Sporadic E 209
1. INTRODUCTION 209
2. OBSERVATIONS OF THE ES LUNAR VARIATIONS 210
3. THEORY OF THE ES LUNAR VARIATIONS 222
REFERENCES 228
Chapter 17. On the Width of the Equatorial Es Belt 230
REFERENCES 233
Chapter 18. The Night-E Layer 234
1. INTRODUCTION 234
2. GEOGRAPHICAL AND TEMPORAL OCCURRENCE 234
3. RELATION WITH THE AURORA 236
4. RELATION WITH MAGNETIC ACTIVITY 238
5. THE IONIZATION PROFILE 241
6. DISCUSSION 244
REFERENCES 246
CHAPTER II Part C 248
Chapter 19. A Theoretical Study of Sporadic-E Structure in the Light of Radio Measurements 250
1. INTRODUCTION 250
2. THIN LAYER MODEL FOR SPORADIC E 250
3. SCATTERING MODEL FOR SPORADIC E 254
4. DISTANCE DEPENDENCE OF SPORADIC-E PROPAGATION 260
5. FREQUENCY DEPENDENCE OF SPORADIC-E PROPAGATION 264
6. CORRELATION BETWEEN foEs AND FIELD STRENGTH 268
7. CONCLUSIONS 270
REFERENCES 272
Chapter 20. The Turbulence Criterion in Stably Stratified Shear Flow and the Origin of Sporadic E 273
1. INTRODUCTION 273
2. THE TURBULENCE CRITERION 277
3. APPLICATION TO THE UPPER ATMOSPHERE 285
REFERENCES 290
Chapter 21. The Formation of a Sporadic-E Layer from a Vertical Gradient in Horizontal Wind 291
1. INTRODUCTION 291
2. DERIVATION OF THE VERTICAL VELOCITY OF THE IONS 292
3. DISCUSSION OF THE VARIATION OF VERTICAL VELOCITY WITH HEIGHT 294
4. THE EFFECT OF A VERTICAL VELOCITY OF IONIZATION ON THE ELECTRON DENSITY DISTRIBUTION IN THE IONOSPHERE 295
5. THE EFFECT OF DIFFUSION ON THE PEAK ELECTRON DENSITY 301
6. THE FORMATION OF SPORADIC E 303
7. THE PERSISTENCE OF A SPORADIC-E LAYER 304
8. THE EFFECT OF A SPORADIC-E CLOUD ON THE EARTH'S MAGNETIC FIELD 305
9. THE ASSOCIATION BETWEEN SPORADIC-E AND F-REGION TRAVELLING DISTURBANCES 305
10. CONCLUSIONS 305
REFERENCES 306
Chapter 22. Structure of Es at Temperate Latitudes 307
INTRODUCTION 307
1. STATISTICAL PROPERTIES 310
2. MONTHLY MEDIAN RESULTS 320
3. PROFILE OF THE Es-LAYER 333
4. TRANSPARENCY CHARACTERISTICS 341
5. THEORETICAL CONCLUSIONS 351
REFERENCES 358
Chapter 23. Interrelations of Sporadic E and Ionospheric Currents 359
1. INTRODUCTION 359
2. EQUATORIAL ES AND THE SOLAR EQUATORIAL ELECTROJET 361
3. Es IN THE TEMPERATE LATITUDES AND THE Sq CURRENT SYSTEM 370
4. Es IN HIGH LATITUDES AND ELECTRIC CURRENTS DURING BAY DISTURBANCES AND GEOMAGNETIC STORMS 376
5. CONCLUSIONS 388
REFERENCES 389
Chapter 24. Concluding Remarks 391
1. INTRODUCTION 391
2. OCCURRENCE OF SPORADIC E 391
3. SPORADIC-E MOVEMENTS 392
4. STRUCTURE OF SPORADIC E 393
5. DISCUSSION ON THE CAUSE OF SPORADIC E 394
6. FUTURE RESEARCH 395
NAME INDEX 396
SUBJECT INDEX 400