Solar and planetary dynamos : proceedings of a NATO Advanced Study Institute held at the Isaac Newton Institute, Cambridge, September 1992

Dynamo Theory Is The Study Of How Large-scale Magnetic Fields Can Arise In Bodies Such As The Earth, Sun And Stars, And It Brings Together Researchers In Such Diverse Subjects As Geophysics, Astronomy And Nuclear Reactor Technology. In This Book Are Papers On The Theory Of Dynamos, Delivered At The Isaac Newton Institute For Mathematical Sciences In Cambridge In September 1992, And These Have Been Carefully Brought Together To Form A Unified Presentation. Topics Covered Include: Modelling Of Solar Magnetic Field Generation, Theoretical Studies Of The Galaxies, And Papers On 'fast Dynamos', Study Of Magnetic Field Regeneration In Fluid Of Very High Electrical Conductivity. This Volume Represents A Comprehensive Record Of Research Into The Theory Of Dynamos. Edited By M.r.e. Proctor, P.c. Matthews And A.m. Rucklidge. Includes Bibliographical References And Index. Cover......Page 1 Title Page......Page 4 Copyright......Page 5 Contents......Page 6 Preface......Page 10 List of Participants......Page 12 Magnetic Noise and the Galactic Dynamo......Page 14 On the Oscillation in Model Z......Page 22 Nonlinear Dynamos in a Spherical Shell......Page 32 The Onset of Dynamo Action in Alpha-lambda Dynamos......Page 40 Multifractality, Near-singularities and the Role of Stretching in Turbulence......Page 48 Note on Perfect Fast Dynamo Action in a Large-amplitude SFS Map......Page 56 A Thermally Driven Disc Dynamo......Page 64 Magnetic Instabilities in Rapidly Rotating Systems......Page 72 Modes of a Flux Ring Lying in the Equator of a Star......Page 82 A Nonaxisymmetric Dynamo in Toroidal Geometry......Page 92 Simulating the Interaction of Convection with Magnetic Fields in the Sun......Page 96 Experimental Aspects of a Laboratory Scale Liquid Sodium Dynamo Model......Page 104 Influence of the Period of an ABC Flow on its Dynamo Action......Page 112 Numerical Calculations of Dynamos for ABC and Related Flows......Page 118 Local Helicity, a Material Invariant for the Odd-dimensional Incompressible Euler Equations......Page 128 On the Quasimagnetostrophic Asymptotic Approximation Related to Solar Activity......Page 134 Simple Dynamical Fast Dynamos......Page 142 A Numerical Study of Dynamos in Spherical Shells with Conducting Boundaries......Page 150 Non-axisymmetric Shear Layers in a Rotating Spherical Shell......Page 158 Testing for Dynamo Action......Page 166 Alpha-quenching in Cylindrical Magnetoconvection......Page 174 On the Stretching of Line Elements in Fluids: an Approach from Differential Geometry......Page 184 Instabilities of Tidally and Precession ally Induced Flows......Page 194 Probability Distribution of Passive Scalars with Nonlinear Mean Gradient......Page 202 Magnetic Fluctuations in Fast Dynamos......Page 208 A Statistical Description of MILD Turbulence in Laboratory Plasmas......Page 216 Compressible Magnetoconvection in Three Dimensions......Page 224 The Excitation of Nonaxisymmetric Magnetic Fields in Galaxies......Page 232 Localized Magnetic Fields in a Perfectly Conducting Fluid......Page 238 Turbulent Dynamo and the Geomagnetic Secular Variation......Page 242 On-Off Intermittency: General Description and Feedback Model......Page 246 Dynamo Action in a Nearly Integrable Chaotic Flow......Page 254 The Dynamo Mechanism in the Deep Convection Zone of the Sun......Page 262 Shearing Instabilities in Magnetoconvection......Page 270 On the Role of Rotation of the Internal Core Relative to the Mantle......Page 278 Evolution of Magnetic Fields in a Swirling Jet......Page 284 Analytic Fast Dynamo Solution for a Two-dimensional Pulsed Flow......Page 288 On Magnetic Dynamos in Thin Accretion Disks Around Compact and Young Stars......Page 300 The Strong Field Branch of the Childress-Soward Dynamo......Page 308 Evidence for the Suppression of the Alpha-effect by Weak Magnetic Fields......Page 316 Turbulent Magnetic Transport Effects and their Relation to Magnetic Field Intermittency......Page 324 Proving the Existence of Negative Isotropic Eddy Viscosity......Page 334 Dynamo Action Induced by Lateral Variation of Electrical Conductivity......Page 342 Spherical Inertial Oscillation and Convection......Page 352 Hydrodynamic Stability of the ABC Flow......Page 360 Dynamos with Ambipolar Diffusion......Page 368 Subject Index......Page 376 Dynamo theory is the study of how large scale magnetic fields can arise in bodies such as the Earth, Sun and stars, and it brings together researchers in such diverse subjects as geophysics astronomy and nuclear reactor technology. In this book are papers on the theory of dynamos, delivered at the Isaac Newton Institute for Mathematical Sciences in Cambridge in September 1992, and these have been carefully brought together to form a unified presentation. Topics covered include: modelling of solar magnetic field generation, theoretical studies of the dynamics of the EarthÃ3⁄4s core, studies of the magnetic fields in galaxies, and papers on 0fast dynamosÃ3⁄4, the study of magnetic field regeneration in fluid of very high electrical conductivity. This volume represents the most comprehensive and up-to-date record of research into the theory of dynamos. Dynamo theory is the study of how large scale magnetic fields can arise in bodies such as the Earth, Sun, and stars. This text brings together researchers in such diverse subjects as geophysics, astronomy, and nuclear reactor technology and covers topics such as modeling of solar magnetic field generation, theoretical studies of the dynamics of the Earth's core, studies of the magnetic fields in galaxies, and papers on "fast dynamos," the study of magnetic field regeneration in fluid of very high electrical conductivity. This volume represents the most comprehensive and up-to-date record of research into the theory of dynamos and will interest students and professors of astrophysics, applied mathematics, and planetary science.