Dynamics and Structure of Quiescent Solar Prominences

Prominences are amazing objects of great beauty whose formation, basic structure and eruption represent one of the basic unsolved problems in Solar Physics. It is now 14 years since the last book on prominences appeared (Tandberg-Hanssen, 1974), during which time much progress in our knowledge of the physics of prominences has been made, and so the time is ripe for a new text book which it is hoped will be a helpful summary of the subject for students, postdocs and solar researchers. Indeed, the last few years has seen an upsurge in interest in prominences due to high­ resolution ground-and space-based observations and advances in theory. For example, an IAU colloquium was held in Oslo (Jensen et al, 1978), a Solar Maximum Mission Workshop took place at Goddard Space Right Center (poland, 1986), an IAU Colloquium is planned in Yugoslavia in September 1989 in prominences and it is expected that the SOHO satellite will be a further stimulus to prominence research. In November 1987 a Workshop on the Dynamics and Structure of Solar Prominences was held in Palma Mallorca at the invitation of Jose Luis Ballester with the aim of bringing observers and theorists together and having plenty of time for in-depth discussions of the basic physics of promi­ nences.

Inhalt

1 Introduction to Quiescent Solar Prominences (E R Priest).- 1.1 Basic Description.- 1.1.1 Different Types.- 1.1.2 Properties.- 1.1.3 Development.- 1.1.4 Structure.- 1.1.5 Eruption.- 1.2 Basic Equations of MHD.- 1.2.1 Magnetohydrostatics.- 1.2.2 Waves.- 1.2.3 Instabilities.- 1.3 Prominence Puzzles.- 2 Overall Properties and Steady Flows (B Schmieder).- 2.1 Basic Properties.- 2.1.1 Description and Classification.- 2.1.2 Fine Structure in H?.- 2.1.3 Evolution of Filaments During the Solar Cycle.- 2.2 Physical Characteristics: Density and Temperature.- 2.2.1 Density and Ionization Degree.- 2.2.2 Non LTE Models.- 2.2.3 Turbulent Velocity and Electron Temperature.- 2.3 Velocity Field and Mass Flux.- 2.3.1 Instrumentation.- 2.3.2 H? Profile Analysis.- 2.3.3 Vertical Motions.- 2.3.4 Horizontal Motions.- 2.3.5 Oscillations.- 2.4 Instability.- 2.4.1 Disparition Brusque of Filaments.- 2.4.2 Model Support.- 2.4.3 Post-Flare Loops and Loop Prominences.- 2.5 Conclusion.- 3 Prominence Environment (O Engvold).- 3.1 Introduction.- 3.2 Helmet Streamers.- 3.2.1 Eclipse Photography.- 3.2.2 Morphology.- 3.2.3 Location of Current Sheet.- 3.2.4 Brightness.- 3.3 Coronal Cavities.- 3.3.1 Brightness and Structure.- 3.3.2 Temperature and Density.- 3.4 Filament Channels.- 3.4.1 Association with Neutral Lines.- 3.4.2 Poleward Migration of Filament Channels.- 3.4.3 Presence of Prominences.- 3.4.4 Temperature and Electron Pressure.- 3.4.5 Cool Matter in the Filament Channels.- 3.5 Prominence-Corona Transition Region.- 3.5.1 Line Emission.- 3.5.2 Empirical Modelling.- 3.5.3 A Fragmented and Dynamic Transition Region.- 3.6 Prominences and Environment.- 3.6.1 Magnetic Fields and Chromospheric Structure.- 3.6.2 Association with Supergranulation Network.- 3.6.3 Dynamics.- 3.6.4 The Mass of Coronal Cavity and Prominence.- 3.6.5 Coronal Voids - a Source of Prominence Mass?.- 3.7 Modelling of the Helmet Streamer/Prominence Complex.- 3.7.1 Helmet Streamer and Cavity.- 3.7.2 Magnetic Field Topology.- 3.7.3 Siphon-Type Models.- 3.8 Conclusions.- 4 Observation of Prominence Magnetic Fields (J L Leroy).- 4.1 Historical Steps.- 4 2 Investigations Based on the Polarimetry of Spectral Lines.- 4.2.1 Zeeman Effect.- 4.2.2 HanleEffect.- 4.2.3 180° Ambiguity.- 4.2.4 Instrumental Achievements.- 4.3 Indirect Magnetic Field Determinations.- 4.4 Magnetic Field at the Photospheric Level.- 4.5 Main Features of the Magnetic Field in Quiescent Prominences.- 4.5.1 Field Strength.- 4.5.2 Angle with Horizontal.- 4.5.3 Angle with Prominence Axis.- 4.5.4 Magnetic Structure with Normal or Inverse Polarity.- 4.5.5 Homogeneity of the Field.- 4.6 Some Important Problems.- 4.6.1 Magnetic Field in Sub Arc Second Structures.- 4.6.2 Paradox of Fine Vertical Structures.- 4.6.3 Determination of Currents.- 4.6.4 Evolution of Prominence Magnetic Structure.- 5 The Formation of Solar Prominences (J M Malherbe).- 5.1 Introduction.- 5.2 Overview of Observations.- 5.3 Main MHD Instabilities Involved in Prominence Formation.- 5.3.1 Radiative Thermal Instability.- 5.3.2 Resistive Instabilities.- 5.4 Steady Reconnection in Current Sheets.- 5.4.1 Incompressible and Compressible Theories.- 5.4.2 Unification of Different Regimes.- 5.5 Static Models.- 5.5.1 Condensation in a Loop.- 5.5.2 Condensation in an Arcade.- 5.5.3 Condensation in a Sheared Magnetic Field.- 5.5.4 Condensation in a Current Sheet.- 5.6 Dynamic Models: Injection from the Chromosphere into Closed Loops.- 5.6.1 Surge-Like Models.- 5.6.2 Evaporation Models.- 5.7 Dynamic Models: Condensation in Coronal Current Sheets.- 5.7.1 Numerical Simulations.- 5.7.2 Role of Shock Waves in Condensation Process.- 5.8 Unsolved Problems.- 5.9 Conclusion.- 6 Structure and Equilibrium of Prominences (U Anzer).- 6.1 Introduction.- 6.2 Prominence Models.- 6.2.1 Global Structure.- 6.2.1.1 Two-Dimensional Equilibria.- 6.2.1.1.1 Models with Normal Magnetic Polarity.- 6.2.1.1.2 Models with Inverse Magnetic Polarity.- 6.2.1.1.3 Force-Free Fields.- 6.2.1.2 Quasi-Three-Dimensional Models.- 6.2.1.3 Support by Alfven Waves.- 6.2.2 Internal Structure and Thermal Equilibrium.- 6.2.2.1 Hydrostatic Equilibrium.- 6.2.2.2 Thermal Equilibrium.- 6.3 Concluding Remarks.- 7 Stability and Eruption of Prominences (A W Hood).- 7.1 Introduction.- 7.2 Description of MHD Instabilities.- 7.3 Methods of Solution.- 7.3.1 Normal Modes.- 7.3.2 Energy Method.- 7.3.3 Non Equilibrium.- 7.4 Effect of the Dense Photosphere.- 7.4.1 Physical Arguments.- 7.4.2 Ballooning Modes.- 7.5 Coronal Arcades.- 7.5.1 Distributed Current Models - Eruptive Instability.- 7.5.2 Localised Modes - Small Scale Structure.- 7.5.3 Arcades Containing a Current Sheet.- 7.6 Thermal Stability.- 7.7 Resistive Instabilities - Tearing Modes.- 7.7.1 Introduction.- 7.7.2 Estimate of Tearing Mode Growth Rate.- 7.7.3 Effect of Line Tying.- 7.8 Simple Model of Prominence Eruption and a Coronal Mass Ejection.- 7.9 Conclusions and Future Work.- References.