Solar System Magnetic Fields

In September 1984 a Summer School on Solar System Plasmas was held at Imperial College with the support of the Science and Engineering Research Council. An excellent group of lecturers was assembled to give a series of basic talks on the various aspects of the subject, aimed at Ph. D. students or researchers from related areas wanting to learn about the plasma physics of the solar system. The students were so appreciative of the lectures that it was decided to write them up as the present book. Traditionally, different areas of solar system science, such as solar and magnetospheric physics, have been studied by separate communities with little contact. However, it has become clear that many common themes cut right across these distinct topics, such as magnetohydrodynamic instabilities and waves, magnetic reconnect ion , convection, dynamo activity and particle acceleration. The plasma parameters may well be quite different in the Sun's atmosphere, a cometary tailor Jupiter's magnetosphere, but many of the basic processes are similar and it is by studying them in different environments that we come to understand them more deeply. Furthermore, direct in situ measurements of plasma properties at one point in the solar wind or the magnetosphere complement the more global view by remote sensing of a similar phenomenon at the Sun.

Inhalt
1 Introduction to Solar Activity.- 1.1 Some Basic Properties of the Sun.- 1.2 Basic Equations of Magnetohydrodynamic.- 1.3 Sunspots.- 1.4 Prominences.- 1.5 The Corona.- 1.6 Solar Flares.- 1.7 Conclusion.- References.- 2 An Introduction to Magnetospheric MHD.- 2.1 Introduction.- 2.2 Why is There a Magnetosphere?.- 2.3 The Open Magnetosphere Morphology.- 2.4 Momentum Transfer.- 2.5 Magnetospheric Substorms.- 2.6 Magnetohydrodynamic Waves.- References.- 3 Magnetohydrodynamic Waves.- 3.1 Structuring and Stratification.- 3.2 Waves in a Magnetically Structured Atmosphere.- 3.3 Waves in a Uniform Medium.- 3.4 Waves in Discretely Structured Media.- 3.4.2 Compressible Medium.- 3.5 Oscillations in a Low ?-Gas.- 3.6 Damped Alfvén Waves.- 3.7 Waves in Stratified Atmospheres.- 3.8 Slender Flux Tubes.- References.- 4 MHD Instabilities.- 4.1 Equilibrium Solutions.- 4.2 Physical Description of MHD Instabilities.- 4.3 Linearised MHD Equations.- 4.4 Normal Modes Method.- 4.5 Energy (or Variational) Method.- 4.6 The Rayleigh-Taylor Instability.- 4.7 The Sharp Pinch Normal Modes.- 4.8 General Cylindrical Pinch Energy Method.- 4.9 Necessary and Sufficient Conditions Newcomb's Analysis.- 4.10 Resistive Instabilities Tearing Modes.- 4.11 Applications of MHD Instabilities.- References.- 5 Magnetic Reconnect.- 5.1 Introduction.- 5.2 Reconnection: What It Is and What It Does.- 5.3 Fluid (MHD) Models of Reconnection.- 5.4 The Single-Particle Approach in a Collision-Free Plasma.- References.- 6 Magnetoconvection.- 6.1 Small Flux Tubes.- 6.2 Convection in a Strong Magnetic Field.- 6.3 Structure of the Large-Scale Magnetic Field.- References.- 7 Aspects of Dynamo Theory.- 7.1 The Homopolar Disc Dynamo.- 7.2 The Stretch-Twist-Fold Dynamo.- 7.3 Behaviour of the Dipole Moment in aConfined System.- 7.4 The Pros and Cons of Dynamo Action.- 7.5 Flux Expulsion and Topological Pumping.- 7.6 Mean-Field Electrodynamics.- 7.7 Some Properties of the Pseudo-Tensors ?ij and ?ijk.- 7.8 The Solar Dynamo.- 7.9 Magnetic Buoyancy as an Equilibration Mechanism.- References.- 8 Solar Wind and the Earth's Bow Shock.- 8.1 The Solar Wind as a Fluid.- 8.2 The Solar Wind as a Plasma.- 8.3 The Earth's Bow Shock.- 8.4 Conclusion.- References.- 9 Planetary Magnetospheres.- 9.1 Comparative Theory of Magnetospheres.- 9.2 Planetary Magnetospheres.- 9.3 Conclusions.- References.- 10 Comets.- 10.1 Introduction to Comet Structure.- 10.2 Interaction between the Solar Wind and the Comet.- 10.3 Production of Neutral Gas.- 10.4 Ionisation.- 10.5 Ion Pick-Up.- 10.6 Principal Plasma Regimes.- 10.7 Magnetohydrodynamic Flow at a Comet.- 10.8 Special Features of the Morphology.- 10.9 Conclusion.- References.