Physics of Magnetospheric Substorms

1 Open Magnetosphere and the Auroral Oval.- 1.1. Open Magnetosphere.- 1.2. Auroral Oval.- 1.3. Open Magnetosphere and the Auroral Oval.- 1.3.1. Solar Energetic Particles and the Auroral Oval.- 1.3.2. Field-Aligned Currents and the Auroral Oval.- (a) Distribution of Field-Aligned Currents above the Polar Ionosphere.- (b) Field-Aligned Currents and Auroral Arcs.- 1.3.3. Field-Aligned Currents and Ionospheric Currents.- (a) Formulation.- (b) Model.- (c) Results.- 1.3.4. Electric Field Distribution and the Auroral Oval.- (a) Observations.- (b) Theoretical Studies.- 1.3.5. Plasma Convection in the Equatorial Plane and the Polar Cap.- (a) Observations.- (b) Theoretical Studies.- 1.3.6. Three-Dimensional Magnetospheric Current System.- (a) Fejer-Swift-Vasyliunas-Wolf (FSVW) Model.- (b) Boström-Rostoker (BR) Model.- 1.3.7. Sqp Variation and the Auroral Oval.- 1.4. Solar Wind — Magnetosphere Dynamo.- 1.4.1. Electromotive Force and Power.- 1.4.2. Steady State Merging.- (a) Sweet-Parker’s Model.- (b) Petschek’s Model.- (c) Sonnerup’s Model.- 1.4.3. Production Rate of the Open Flux.- References.- 2 Auroras and Auroral Particles.- 2.1. Introduction.- 2.1.1. Montage Photographs of the Auroral Oval.- 2.1.2. Schematic Distribution Pattern of Auroras.- 2.2. Auroras in Different Local Time Sectors.- 2.2.1. Discrete Auroras and Diffuse Auroras in the Night Sector.- 2.2.2. Midday Auroras.- 2.2.3. Polar Cap Auroras.- 2.3. Auroral Electrons: The Statistical Precipitation Pattern.- 2.4. Auroral Electrons: Spectra of Auroral Electrons.- 2.4.1. Evening and Midnight Sectors.- (a) Satellite Observations.- (b) Rocket Observations.- 2.4.2. Morning Sector.- 2.4.3. Noon (Cusp) Sector.- 2.4.4. Polar Cap.- 2.5. Auroral Electrons and Field-Aligned Currents.- 2.5.1. Satellite Observations.- 2.5.2. Rocket Observations.- 2.6. Auroral Particles and Atmospheric Emissions.- 2.7. Auroral Protons.- 2.8. Auroral Helium Ions (He++, He+) and Oxygen Ions (O+).- 2.8.1. Auroral Helium Ions.- 2.8.2. Auroral Oxygen Ions.- 2.9. Auroral Oval and the Polar Ionosphere.- 2.9.1. F Region.- 2.9.2. E Region.- 2.10. Summary.- References.- 3 Distribution of Plasmas in the Magnetosphere.- 3.1. Five Plasma Domains.- 3.2. Plasma Mantle.- 3.2.1. Frontal Region of the Magnetosphere.- 3.2.2. Magnetotail (X > -30 RE).- 3.2.3. Magnetotail at the Lunar Distance (X ? ?60 RE).- 3.2.4. Distant Magnetotail (X ~ ?500 ~ -1000 RE).- 3.3. Polar Cusp.- 3.4. Plasma Sheet.- 3.4.1. Plasma Sheet During Very Quiet Periods.- 3.4.2. Average Energy Characteristics.- (a) ?10 RE > X > ?30 RE.- (b) Plasma Sheet at the Lunar Distance (X ? ?60 RE).- 3.5. Origin and Dynamics of the Sheet Plasma.- 3.5.1. Meridional Convection of Magnetospheric Plasma.- 3.5.2. Electric Currents, Magnetic Field Structure and the Balance of Stresses in the Plasma Sheet.- (a) Two-Dimensional Maxwell-Vlasov and Macroscopic Approaches.- (b) Kinetic Approaches.- 3.6. Van Allen Belts.- 3.6.1. Ring Current Belt: the Quiet Time Belt.- 3.6.2. Electron Belt.- 3.7. Plasmasphere.- 3.8. Magnetospheric Plasmas and Auroral Particles.- 3.8.1. Oval Belt.- 3.8.2. Annular Belt.- 3.9. Acceleration Processes of Arc-Producing Auroral Electrons.- 3.9.1. Introduction.- 3.9.2. Auroral Arcs and Their Topological Relation with the Magnetospheric Structure.- 3.9.3. Arc Energization System.- 3.9.4. Possible Processes in the Wave-Particle Interaction Region.- (a) Current Driven Instabilities.- (b) Double Layer.- References.- 4 Responses of the Magnetosphere to Interplanetary Disturbances.- 4.1. Interplanetary Disturbances.- 4.2. Interplanetary Pressure Disturbances and Magnetospheric Responses.- 4.3. Changes of the IMF EW Component and Magnetospheric Responses.- 4.3.1. Merging of the Geomagnetic Field Lines with the IMF EW Component.- 4.3.2. Observations.- 4.4. Changes of the IMF NS Component and Magnetospheric Responses.- 4.4.1. Introduction.- 4.4.2. Merging with the IMF of an Arbitrary Angle.- 4.4.3. Erosion of the Dayside Magnetosphere.- (a) Magnetopause Motion.- (b) Cusp Motion.- 4.4.4. Magnetic Flux Transfer to the Magnetotail.- (a) High Latitude Lobe Field BT.- (b) Radius of the Magnetotail RT.- (c) Plasma Sheet Thinning.- 4.4.5. Enhanced Convection in the Plasma Sheet.- (a) Earthward Advance of the Plasma Sheet.- (b) Tendency Toward the Tail-Like Field.- (c) Slow Decrease of the H Component at the Synchronous Distance and in Low Latitudes.- 4.4.6. Polar Cap Phenomena.- (a) Dawn-to-Dusk Electric Field in the Polar Region.- (b) Expansion of the Auroral Oval.- (c) DP-2 Variation.- 4.4.7. Correlation Between Bs (= -Bz) and the AE Index.- (a) Arnoldy’s Study of the Relationship between Bs and the AE Index.- (b) The AE Index.- 4.4.8. Summary.- References.- 5 Magnetospheric Substorms: Introduction.- 5.1. A New Classification of Magnetospheric Disturbances.- 5.1.1. Reversible or Quasi-Reversible Disturbances.- 5.1.2. Irreversible Disturbances.- 5.2. Substorm Energy ?? and Substorm Function ? = ?(?D).- 5.2.1. Ground State of the Magnetosphere.- 5.2.2. Substorm Function ? = ?(?D).- 5.3. Substorm Intensity.- 5.3.1. Kinetic Energy of Auroral Particles.- 5.3.2. Joule Heat Energy of the Auroral Electrojet.- 5.4. Time-Dependent Merging.- 5.4.1. Stability of the Plasma Sheet.- 5.4.2. Numerical Simulation of Reconnection.- 5.4.3. Plasma Processes.- 5.4.4. Substorm Time Constants.- 5.4.5. Short Review of Theories of the Magnetospheric Substorm.- 5.5. Magnetospheric Substorms.- 5.5.1. Neutral Line Formation — Enhanced Reconnection or Plasma Sheet Deflation — Enhanced Reconnection.- 5.5.2. Enhancement of the Auroral Oval Circuit Current.- 5.5.3. Penetration of the Convection Electric Field into the Inner Magnetosphere and the Resulting Plasma Injection.- 5.6. Geomagnetic and Magnetospheric Storms.- References.- 6 Magnetotail Phenomena During Magnetospheric Substorms.- 6.1. Introduction.- 6.2. B Vector Dipping.- 6.3. Plasma Sheet Thinning.- 6.3.1. Profile of Thinning.- (a) Z-axis Dependence.- (b) Profile in the Y-Z Plane.- (c) Profile in the X-Y Plane.- (d) Profile in the X-Z Plane.- 6.3.2. Timing of Thinning.- 6.3.3. Thinning and the Bz Component Reversal.- 6.3.4. Summary.- 6.4. Magnetotail Field BT and Radius RT.- 6.4.1. Decrease of the Magnetotail Lobe Field BT.- 6.4.2. Decrease of the Radius of the Magnetotail RT.- 6.5. Auroral Bulge.- 6.5.1. Auroral Bulge.- 6.5.2. Auroral Particles in the Bulge.- 6.5.3. Increase of the Magnetic Field Component Bz.- 6.5.4. Increase of Cosmic Ray Proton Cut-off.- 6.6. Plasma Sheet Expansion.- 6.7. Plasma Flow.- 6.7.1. Vela Satellite Observations.- 6.7.2. IMP-6 Satellite Observations.- 6.7.3. Flow Reversal.- 6.8. Other Important Magnetotail Phenomena.- 6.8.1. Brief Appearance of Energetic Electrons in the Plasma Sheet.- 6.8.2. Leakage of Plasma Sheet Particles into the Magnetosheath.- 6.8.3. ‘Geomagnetic Storm Particles’.- 6.8.4. Dawn-Dusk Asymmetry of the Proton and Electron Distributions.- (a) Production of Sub-Relativistic Protons and Electrons and Their Dawn-Dusk Asymmetry.- (b) Dawn-Dusk Asymmetry of Precipitating Protons and Electrons.- (c) Summary.- 6.8.5. Summary of the Magnetotail Observations.- (a) Plasma Sheet Thinning.- (b) Plasma Sheet Expansion.- (c) Magnetic Field Variations.- References.- 7 Magnetospheric Currents During Substorms.- 7.1. Introduction.- 7.2. Field-Aligned Currents.- 7.2.1. Observations in the Magnetotail.- 7.2.2. Observations above the Ionosphere.- 7.2.3. Ground Observations.- 7.2.4. Positive Bays in Low Latitudes and Positive Bz Variations at the Synchronous Distance and in the Magnetotail.- 7.2.5. Modeling the Magnetospheric Substorm in Terms of the Substorm Current System.- (a) Model.- (b) Positive Bz Changes.- (c) Poleward Shift of the Feet of the Geomagnetic Field Lines.- (d) Equatorward Shift of the Cusp.- (e) Summary.- 7.3. Field-Aligned Currents and the Auroral Electrojets.- 7.3.1. Introduction.- 7.3.2. Examples.- (a) 1973, March 6.- (b) 1973, March 9.- 7.3.3. Relative Location of the Auroral Electrojets with respect to Field-Aligned Currents in the Evening Sector: A Statistical Result and Summary.- 7.3.4. Model Calculation.- 7.4. Auroral Electrojets.- 7.4.1. Auroral Electrojet and Global Auroral Features.- (a) Examples.- (b) Summary.- 7.5. Cross-Section of the Electrojets.- 7.5.1. Latitudinal Profile of the Three-Component Changes.- 7.5.2. Development of the Electrojets.- (a) A Substorm on 1970, June 15.- (b) A Substorm on 1970, July 14.- (c) A Substorm on 1971, December 23.- 7.5.3. Radar Auroras.- 7.6. Latitudinal Cross-Section of the Auroral Electrojet and its Relation to the Interplanetary Magnetic Field Polarity.- 7.7. Ionospheric Currents and Electric Fields.- 7.7.1. Model Study.- 7.7.2. Chatanika Radar Observations.- (a) Electric Field, Current and Conductivity.- (b) North-South Current and the D Component.- (c) Electric Field and Auroral Activity.- 7.7.3. Balloon Observations.- 7.7.4. Barium Cloud Observations.- (a) Auroral Oval.- (b) Polar Cap.- 7.7.5. Rocket Observations.- 7.8. Thermospheric and Ionospheric Disturbances.- References.- 8 Penetrating Convection Electric Field, Plasma Injection and Plasmasphere Disturbances.- 8.1. Introduction.- 8.2. Penetration of the Convection Electric Field into the Inner Magnetosphere and the Resulting Plasma Injection.- 8.2.1. Observations.- (a) Plasma Injection at the Geosynchronous Distance.- (b) Enhancement of the Westward Electric Field in the Plasmasphere.- 8.2.2. Theoretical Estimates.- 8.3. Relationship between Particles at the Geosynchronous Distance and Auroral Activity near the Geomagnetically Conjugate Point.- 8.4. ‘The Fault Line’.- 8.4.1. Dawnside of the Fault Line.- 8.4.2. Duskside of the Fault Line.- 8.5. Drift Motions.- 8.5.1. Protons.- (a) Satellite Observations of Drifting Protons.- (b) Precipitating Protons.- (c) IPDP Pulsations.- 8.5.2. Energetic Electrons.- (a) Satellite Observations of Drifting Electrons.- (b) Ground-Based Observations of Drifting Electrons.- 8.6. Deformation of the Plasmasphere and Associated Ionospheric Disturbances.- References.- 9 Solar-Terrestrial Relations and Magnetospheric Substorms.- 9.1. Interplanetary Disturbances.- 9.1.1. Basic Solar-Interplanetary Magnetic Field Structure.- 9.1.2. High Speed Solar Wind Streams and Geomagnetic Disturbances.- 9.1.3. Transient Solar Activities and Associated Interplanetary Disturbances.- 9.2. Morphological Model of Magnetospheric Substorms.- 9.2.1. Basic Requirements for Models.- 9.2.2. Description of a Model.- (a) Deflation of the Plasma Sheet.- (b) Magnetic Energy Conversion.- 9.2.3. Critical Tests and Unsolved Problems.- 9.3. Concluding Remarks.- References.- Index of Names.- Index of Subjects.