Balogh The Heliosphere through the Solar Activity Cycle

1. Auflage 2007
ISBN: 978-3-540-74302-6
Verlag: Springer-Verlag
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 286 Seiten

Understanding how the Sun changes though its 11-year sunspot cycle and how these changes affect the vast space around the Sun - the heliosphere - has been one of the principal objectives of space research since the advent of the space age. This book presents the evolution of the heliosphere through an entire solar activity cycle. The last solar cycle (cycle 23) has been the best observed from both the Earth and from a fleet of spacecraft. Of these, the joint ESA-NASA Ulysses probe has provided continuous observations of the state of the heliosphere since 1990 from a unique vantage point, that of a nearly polar orbit around the Sun. Ulysses' results affect our understanding of the heliosphere from the interior of the Sun to the interstellar medium - beyond the outer boundary of the heliosphere. Written by scientists closely associated with the Ulysses mission, the book describes and explains the many different aspects of changes in the heliosphere in response to solar activity. In particular, the authors describe the rise in solar activity from the last minimum in solar activity in 1996 to its maximum in 2000 and the subsequent decline in activity.

Autoren/Hrsg.

Balogh, Andre

Inhaltsverzeichnis

1;Contents;5
2;Preface;10
3;Acknowledgments;13
4;Figures;14
5;Abbreviations and acronyms;19
6;The heliosphere: Its origin and exploration;22
6.1;1.1 INTRODUCTION;22
6.2;1.2 THE PRE–SPACE AGE HELIOSPHERE;23
6.2.1;1.2.1 The expanding hot solar atmosphere;23
6.2.2;1.2.2 Energetic particles in the heliosphere;26
6.3;1.3 THE HELIOSPHERE AND ITS BOUNDARIES;28
6.3.1;1.3.1 The size of the heliosphere;29
6.3.2;1.3.2 The termination shock and beyond: Voyager 1 results;32
6.4;1.4 HELIOSPHERIC STRUCTURE AND DYNAMICS OVER THE SOLAR CYCLE ;33
6.4.1;1.4.1 The solar wind through the solar activity cycle;33
6.4.2;1.4.2 Close to solar-minimum activity: corotating interaction regions;35
6.4.3;1.4.3 Around solar-maximum activity: coronal mass ejections;35
6.4.4;1.4.4 Energetic solar particles;36
6.4.5;1.4.5 Large-scale structures and the modulation of cosmic rays;37
6.5;1.5 THE EXPLORATION OF THE HELIOSPHERE;37
6.5.1;1.5.1 Inner heliosphere;37
6.5.2;1.5.2 Earth-orbiting missions;38
6.5.3;1.5.3 L1 spacecraft;38
6.5.4;1.5.4 Outer heliosphere;39
6.5.5;1.5.5 Future heliosphere missions;39
6.5.6;1.5.6 Summary;40
6.6;1.6 REFERENCES;40
7;Solar cycle 23;42
7.1;2.1 INTRODUCTION;42
7.2;2.2 SOLAR ACTIVITY CYCLES;43
7.3;2.3 CYCLE 23;48
7.4;2.4 THE EXTENSION OF CYCLE 23 INTO THE INTERPLANETARY MEDIUM;52
7.5;2.5 SUMMARY;58
7.6;2.6 ACKNOWLEDGMENTS;58
7.7;2.7 REFERENCES;59
8;The solar wind throughout the solar cycle;61
8.1;3.1 INTRODUCTION: THE PRE-ULYSSES PICTURE;61
8.2;3.2 MORPHOLOGY;64
8.3;3.3 DISTRIBUTION FUNCTIONS;69
8.3.1;3.3.1 H and He distribution functions;69
8.3.2;3.3.2 Heavy ion distribution functions;71
8.4;3.4 COMPOSITION;73
8.4.1;3.4.1 Charge-state composition;74
8.4.2;3.4.2 Elemental composition;78
8.4.3;3.4.3 Correlation between composition and kinetic parameters;81
8.5;3.5 TRANSIENTS;82
8.5.1;3.5.1 Corotating interaction regions;82
8.5.2;3.5.2 Coronal mass ejections;84
8.5.3;3.5.3 Other transients;88
8.6;3.6 THE ULYSSES PICTURE: THE SOLAR WIND IN FOUR DIMENSIONS;90
8.7;3.7 ACKNOWLEDGMENTS;91
8.8;3.8 REFERENCES;91
9;The global heliospheric magnetic field;99
9.1;4.1 INTRODUCTION;99
9.2;4.2 THE HELIOSPHERIC MAGNETIC FIELD: A GLOBAL PERSPECTIVE;100
9.2.1;4.2.1 The Parker field model;100
9.2.2;4.2.2 BR and open flux;104
9.2.3;4.2.3 BT and the Parker spiral angle;107
9.2.4;4.2.4 The north–south component, BN;113
9.3;4.3 THE HELIOSPHERIC MAGNETIC FIELD AT SOLAR MINIMUM;115
9.3.1;4.3.1 Dipole tilt, sector structure, and heliospheric current sheet;115
9.3.2;4.3.2 Sector structure and source surface models;117
9.3.3;4.3.3 Heliospheric current sheet and plasma sheet: properties;118
9.3.4;4.3.4 The HMF and testing of source surface models;121
9.4;4.4 THE HMF AND HELIOSPHERIC STRUCTURE ;123
9.4.1;4.4.1 Solar and solar wind structure;123
9.4.2;4.4.2 Evolution and interaction of fast and slow wind;125
9.4.3;4.4.3 CIRs, shocks, and dipole tilt;128
9.4.4;4.4.4 CIRs, energetic particles, and their access to high latitudes;131
9.4.5;4.4.5 Corotating rarefaction regions and the spiral angle;136
9.4.6;4.4.6 Magnetic .eld strength and flux deficit;138
9.5;4.5 NORTH–SOUTH ASYMMETRY OF THE SOLAR DIPOLE AND ITS SOLAR CYCLE VARIATION;140
9.6;4.6 TEMPORAL VARIATIONS—CORONAL MASS EJECTIONS;143
9.7;4.7 HMF AT SOLAR MAXIMUM AND ITS SOLAR CYCLE VARIATION ;145
9.7.1;4.7.1 Introduction to solar maximum and the Hale cycle;145
9.7.2;4.7.2 Solar magnetic field at solar maximum;145
9.7.3;4.7.3 Magnetic dipole and polarity reversal;148
9.7.4;4.7.4 Inclination of the HCS and solar dipole;149
9.7.5;4.7.5 The radial component at solar maximum;154
9.7.6;4.7.6 Solar cycle variation of open flux;156
9.7.7;4.7.7 Solar cycle variations in field magnitude;158
9.8;4.8 SUMMARY—SOLAR CYCLE VARIATIONS;159
9.9;4.9 ACKNOWLEDGMENTS;164
9.10;4.10 REFERENCES;164
10;Heliospheric energetic particle variations;171
10.1;5.1 ENERGETIC PARTICLE POPULATIONS IN THE INNER HELIOSPHERE;171
10.2;5.2 SOLAR MINIMUM ORBIT (1992–1998);172
10.2.1;5.2.1 Summary of the Ulysses solar-minimum observations;174
10.2.2;5.2.2 Energetic particle origin, transport, and acceleration processes in the solar minimum inner heliosphere -;176
10.3;5.3 SOLAR MAXIMUM ORBIT (1998–2004);179
10.4;5.5 MULTI-SPACECRAFT OBSERVATIONS OF SEP EVENTS: ULYSSES AND NEAR- EARTH OBSERVATIONS;188
10.5;5.6 HELIOSPHERIC ENERGETIC PARTICLE RESERVOIRS;199
10.6;5.7 INFLUENCE OF INTERPLANETARY STRUCTURES ON SEP PROPAGATION;203
10.7;5.9 ACKNOWLEDGMENTS;207
10.8;5.10 REFERENCES;208
11;Galactic and anomalous cosmic rays through the solar cycle: New insights from Ulysses;215
11.1;6.1 INTRODUCTION;215
11.1.1;6.1.1 Particle populations in the heliosphere;215
11.1.2;6.1.2 Cosmic ray modulation;216
11.2;6.2 SELECTED COSMIC RAY OBSERVATIONS;219
11.2.1;6.2.1 Observations close to Earth;220
11.2.2;6.2.2 The transport equation;223
11.2.3;6.2.3 The diffusion tensor;227
11.2.4;6.2.4 Solar wind, magnetic field, and the current sheet;228
11.2.5;6.2.5 Size and geometry of the heliosphere;230
11.2.6;6.2.6 Termination shock and anomalous cosmic rays;231
11.2.7;6.2.7 Local interstellar spectra;232
11.2.8;6.2.8 Cosmic ray modulation models;233
11.2.9;6.2.9 Modeling the 11-year and 22-year cycles;234
11.2.10;6.2.10 The compound modeling approach to long-term modulation;235
11.3;6.3 COSMIC RAY DISTRIBUTION AT SOLAR MINIMA;236
11.3.1;6.3.1 Ulysses observations at solar minimum;238
11.4;6.4 THE TRANSITION FROM SOLAR MINIMUM TO SOLAR MAXIMUM;244
11.4.1;6.4.1 Galactic cosmic rays during the 1990–2000 A> 0 solar magnetic cycle;245
11.4.2;6.4.2 MeV electrons;252
11.5;6.5 SUMMARY ;255
11.5.1;6.5.1 Solar minimum;255
11.5.2;6.5.2 Solar maximum;257
11.5.3;6.5.3 Insights on particle propagation in a turbulent astrophysical plasma;258
11.5.4;6.5.4 Cosmic ray modulation surprises from Ulysses;258
11.6;6.6 ACKNOWLEDGMENTS;259
11.7;6.7 REFERENCES;259
12;Overview: The heliosphere then and now;270
12.1;7.1 INTRODUCTION;270
12.2;7.2 THE KNOWN HELIOSPHERE IN 1992;272
12.2.1;7.2.1 The solar wind and the heliospheric magnetic field;273
12.2.2;7.2.2 Solar wind composition and ionization state;276
12.2.3;7.2.3 Energetic particles and cosmic rays;277
12.2.4;7.2.4 Interstellar and interplanetary neutral gas;279
12.2.5;7.2.5 Interstellar and interplanetary dust;279
12.3;7.3 THE KNOWN HELIOSPHERE AFTER A SOLAR ACTIVITY CYCLE WITH ULYSSES;280
12.3.1;7.3.1 The global view;280
12.3.2;7.3.2 Coronal and heliospheric magnetic fields;283
12.3.3;7.3.3 Composition and ionization state;286
12.3.4;7.3.4 Coronal mass ejections;287
12.3.5;7.3.5 Energetic particles;287
12.3.6;7.3.6 Cosmic rays;291
12.3.7;7.3.7 The heliosphere–interstellar medium interface;293
12.3.8;7.3.8 Summary;294
12.4;7.4 ACKNOWLEDGMENTS;296
12.5;7.5 REFERENCES;296
13;Index;299