Solar Journey: The Significance of Our Galactic Environment for the Heliosphere and Earth (Astrophysics and Space Science Library (338))

Written by experts who created the field, this volume explores uncharted scientific territory, with articles discussing the effect of our galactic environment on the heliosphere, planetary system and Earth. Leading experts in diverse fields discuss the physical changes expected as the heliosphere adjusts to its galactic environment. Topics include the interaction between solar wind and interstellar dust and gas, cosmic ray modulation, magnetospheres, variations in the solar environment, and the cosmic ray isotope record preserved in paleoclimate data. Contents......Page 7 Dedication......Page 6 List of Figures......Page 11 List of Tables......Page 15 Contributing Authors......Page 16 Preface......Page 20 Foreword......Page 22 Acknowledgements......Page 23 1.1. The Underlying Query......Page 24 1.2. Addressing the Query: The Heliosphere and Particle Populations for Different Interstellar Environments......Page 26 1.3. Closing Comments......Page 37 References......Page 41 2 Heliospheric Variation in Response to Changing Interstellar Environments......Page 46 2.1. Introduction......Page 47 2.2. Basic Physics of the Multi-fluid Model......Page 51 2.3. Possible Interstellar Environments......Page 56 2.4. Possible Heliospheric Configurations......Page 59 2.5. Conclusions......Page 69 References......Page 70 3 The Influence of the Interstellar Magnetic Field on the Heliospheric Interface......Page 75 3.1. SW–LISM Interaction Problem......Page 79 3.2. Superfast SW–LISM Interaction......Page 82 3.3. Subfast SW–LISM Interaction......Page 98 3.4. Discussion......Page 99 References......Page 102 4.1. Introduction......Page 109 4.2. Future Intersteller Variations......Page 111 4.3. Magnetospheric Activity......Page 112 4.4. Magnetic Activity at Uranus and Neptune......Page 116 References......Page 119 5.1. Introduction......Page 121 5.2. Characterizing the Physical Environment......Page 122 5.3. Variations in the Galactic Environment......Page 126 5.4. Records of Long Term Variations......Page 132 5.5. Crater Record......Page 143 5.6. Summary......Page 145 References......Page 147 6 Short-term Variations in the Galactic Environment of the Sun......Page 154 6.1. Overview......Page 155 6.2. Solar Journey through Space: The Past 10[sup(4)] to 10[sup(6)] Years......Page 166 6.3. Neighborhood ISM: Cluster of Local Interstellar Clouds......Page 171 6.4. Radiative Transfer Models of Local Partially Ionized Gas......Page 185 6.5. Passages through Nearby Clouds......Page 191 6.6. The Solar Environment and Global ISM......Page 196 6.7. Summary......Page 203 References......Page 205 7 Variations of the Interstellar Dust Distribution in the Heliosphere......Page 215 7.1. The Contemporary Interstellar Dust Environment of the Heliosphere......Page 218 7.2. Consequences of a Changing Interstellar Environment......Page 223 References......Page 224 8 Effects in the Inner Heliosphere Caused by Changing Conditions in the Galactic Environment......Page 229 8.1. Introduction......Page 230 8.2. Observations and Modeling of Neutrals in the Contemporary Heliosphere......Page 234 8.3. Interstellar Neutral Gas and its Secondary Products under Varying Interstellar Conditions......Page 253 References......Page 270 9 Variable Terrestrial Particle Environments During the Galactic Orbit of the Sun......Page 279 9.1. Introductory Remarks on Cosmic Rays and Climate......Page 280 9.2. The Heliosphere in Different Interstellar Environments......Page 281 9.3. Cosmic Ray Spectra......Page 285 9.4 Consequences of Variable Particle Environments......Page 292 References......Page 296 10 The Galactic Cosmic Ray Intensity in the Heliosphere in Response to Variable Interstellar Environments......Page 300 10.1. Introduction......Page 301 10.2. Transport Properties of the Heliospheric Interface......Page 305 10.3. Cosmic Ray Transport Model......Page 310 10.4. Cosmic Ray Modulation in the Global Heliosphere: Local Cloud Environment......Page 315 10.5. Interface Variability Driven by Interstellar Environment Changes: Cosmic Ray Response......Page 318 10.6. Cosmogenic Isotope Response......Page 325 10.7. Conclusion......Page 327 References......Page 328 11 Accretion of Interstellar Material into the Heliosphere and onto Earth......Page 336 11.1. How does an Interstellar Cloud Touch the Solar System and the Earth?......Page 341 11.2. Change of the Ionization Degree and Chemical State in the Circumsolar Flow......Page 347 11.3. Model of the Neutral Gas Flow......Page 348 11.4. Amount of Neutral Gas, Accreted by the Earth......Page 353 11.5. Atmospheric Effects......Page 354 11.6. Ozone Concentration in the Mesosphere......Page 357 11.7. Results and Discussion......Page 358 11.8. Summary......Page 361 References......Page 362 12 Variations of Galactic Cosmic Rays and the Earth's Climate......Page 368 12.1. Introduction......Page 369 12.2. Solar Irradiance......Page 370 12.3. Galactic Cosmic Rays......Page 374 12.4. Solar/GCR-climate Variability......Page 379 12.5. GCR-cloud-climate Mechanisms......Page 394 12.6. Conclusions and Future Prospects......Page 407 References......Page 409 C......Page 417 E......Page 418 I......Page 419 M......Page 420 S......Page 421 T......Page 422 Y......Page 423 Contents 7 Dedication 6 List of Figures 11 List of Tables 15 Contributing Authors 16 Preface 20 Foreword 22 Acknowledgements 23 1 Introduction: Paleoheliosphere versus PaleoLISM 24 1.1. The Underlying Query 24 1.2. Addressing the Query: The Heliosphere and Particle Populations for Different Interstellar Environments 26 1.3. Closing Comments 37 References 41 2 Heliospheric Variation in Response to Changing Interstellar Environments 46 2.1. Introduction 47 2.2. Basic Physics of the Multi-fluid Model 51 2.3. Possible Interstellar Environments 56 2.4. Possible Heliospheric Configurations 59 2.5. Conclusions 69 References 70 3 The Influence of the Interstellar Magnetic Field on the Heliospheric Interface 75 3.1. SW–LISM Interaction Problem 79 3.2. Superfast SW–LISM Interaction 82 3.3. Subfast SW–LISM Interaction 98 3.4. Discussion 99 References 102 4 Interstellar Conditions and Planetary Magnetospheres 109 4.1. Introduction 109 4.2. Future Intersteller Variations 111 4.3. Magnetospheric Activity 112 4.4. Magnetic Activity at Uranus and Neptune 116 References 119 5 Long-term Variations in the Galactic Environment of the Sun 121 5.1. Introduction 121 5.2. Characterizing the Physical Environment 122 5.3. Variations in the Galactic Environment 126 5.4. Records of Long Term Variations 132 5.5. Crater Record 143 5.6. Summary 145 References 147 6 Short-term Variations in the Galactic Environment of the Sun 154 6.1. Overview 155 6.2. Solar Journey through Space: The Past 10[sup(4)] to 10[sup(6)] Years 166 6.3. Neighborhood ISM: Cluster of Local Interstellar Clouds 171 6.4. Radiative Transfer Models of Local Partially Ionized Gas 185 6.5. Passages through Nearby Clouds 191 6.6. The Solar Environment and Global ISM 196 6.7. Summary 203 References 205 7 Variations of the Interstellar Dust Distribution in the Heliosphere 215 7.1. The Contemporary Interstellar Dust Environment of the Heliosphere 218 7.2. Consequences of a Changing Interstellar Environment 223 References 224 8 Effects in the Inner Heliosphere Caused by Changing Conditions in the Galactic Environment 229 8.1. Introduction 230 8.2. Observations and Modeling of Neutrals in the Contemporary Heliosphere 234 8.3. Interstellar Neutral Gas and its Secondary Products under Varying Interstellar Conditions 253 References 270 9 Variable Terrestrial Particle Environments During the Galactic Orbit of the Sun 279 9.1. Introductory Remarks on Cosmic Rays and Climate 280 9.2. The Heliosphere in Different Interstellar Environments 281 9.3. Cosmic Ray Spectra 285 9.4 Consequences of Variable Particle Environments 292 References 296 10 The Galactic Cosmic Ray Intensity in the Heliosphere in Response to Variable Interstellar Environments 300 10.1. Introduction 301 10.2. Transport Properties of the Heliospheric Interface 305 10.3. Cosmic Ray Transport Model 310 10.4. Cosmic Ray Modulation in the Global Heliosphere: Local Cloud Environment 315 10.5. Interface Variability Driven by Interstellar Environment Changes: Cosmic Ray Response 318 10.6. Cosmogenic Isotope Response 325 10.7. Conclusion 327 References 328 11 Accretion of Interstellar Material into the Heliosphere and onto Earth 336 11.1. How does an Interstellar Cloud Touch the Solar System and the Earth? 341 11.2. Change of the Ionization Degree and Chemical State in the Circumsolar Flow 347 11.3. Model of the Neutral Gas Flow 348 11.4. Amount of Neutral Gas, Accreted by the Earth 353 11.5. Atmospheric Effects 354 11.6. Ozone Concentration in the Mesosphere 357 11.7. Results and Discussion 358 11.8. Summary 361 References 362 12 Variations of Galactic Cosmic Rays and the Earth's Climate 368 12.1. Introduction 369 12.2. Solar Irradiance 370 12.3. Galactic Cosmic Rays 374 12.4. Solar/GCR-climate Variability 379 12.5. GCR-cloud-climate Mechanisms 394 12.6. Conclusions and Future Prospects 407 References 409 Index 417 A 417 B 417 C 417 D 418 E 418 F 419 G 419 H 419 I 419 J 420 K 420 L 420 M 420 N 421 O 421 P 421 Q 421 R 421 S 421 T 422 U 423 V 423 W 423 X 423 Y 423

Humans evolved when the Sun was in the great void of the Local Bubble. The Sun entered the present environment of interstellar clouds only during the late Quaternary. Astronomical data reveal these long and short term changes in our galactic environment. Theoretical models then tell us how these changes affect interplanetary particles, planetary magnetospheres, and the Earth itself. Cosmic rays leave an isotopic signature in the paleoclimate record that helps trace the solar journey through space.

Solar Journey: The Significance of Our Galactic Environment for the Heliosphere and Earth lays the foundation for an interdisciplinary study of the influence of interstellar material on the solar system and Earth as we travel through the Milky Way Galaxy. The solar wind bubble responds dynamically to interstellar material flowing past the Sun, regulating interstellar gas, dust, and cosmic particle fluxes in the interplanetary medium and the Earth. Cones of interstellar gas and dust focused by solar gravity, the magnetospheres of the outer planets, and cosmic rays at Earth all might yield the first hints of changes in our galactic environment.

Twelve articles from leading experts in diverse fields discuss the physical changes expected as the heliosphere adjusts to its galactic environment. Topics include the interaction between the solar wind and interstellar dust and gas, cosmic ray modulation, magnetospheres, temporal variations in the solar environment, and the cosmic ray isotope record preserved in paleoclimate data.

The breadth of processes discussed in this book make it a valuable resource for scientists and students doing research in the fields of Space Physics, Astronomy and the Paleoclimate.

I admire the great care that Priscilla Frisch has taken in the editorial work, the balanced subjects, the attractive and clear figures. Also the general topic is well chosen and the various chapters are presented very clearly. - C. de Jager

Solar Journey: The Significance of Our Galactic Environment for the Heliosphere and Earth lays the foundation for an interdisciplinary study of the influence of interstellar material on the solar system and Earth as we travel through the Milky Way Galaxy. The solar wind bubble responds dynamically to interstellar material flowing past the Sun, regulating interstellar gas, dust, and cosmic particle fluxes in the interplanetary medium and the Earth. Cones of interstellar gas and dust focused by solar gravity, the magnetospheres of the outer planets, and cosmic rays at Earth all might yield the first hints of changes in our galactic environment. Twelve articles from leading experts in diverse fields discuss the physical changes expected as the heliosphere adjusts to its galactic environment. Topics include the interaction between the solar wind and interstellar dust and gas, cosmic ray modulation, magnetospheres, temporal variations in the solar environment, and the cosmic ray isotope record preserved in paleoclimate data.