Solar dynamo theory : Solar dynamo theory: a new look at the origin of small-scale magnetic fields

  title={Solar dynamo theory : Solar dynamo theory: a new look at the origin of small-scale magnetic fields},
  author={Fausto Cattaneo and David W. Hughes},
  journal={Astronomy \& Geophysics},
Fausto Cattaneo and David W Hughes delve beneath the surface of the Sun with numerical models of turbulent convection. Although magnetic dynamo action is traditionally associated with rotation, fast dynamo theory shows that chaotic flows, even without rotation, can act as efficient small-scale dynamos. Indeed, numerical simulations suggest that granular and supergranular convection may generate locally a substantial part of the field in the quiet photosphere. 
Global models of the magnetic Sun
  • A. Brun, L. Jouve
  • Physics
    Proceedings of the International Astronomical Union
  • 2007
Abstract We briefly present recent simulations of the internal magnetism of the Sun with the 3-D ASH code and with the 2-D STELEM code. The intense magnetism of the Sun is linked to local and global
Understanding the solar dynamo
olar magnetic activity is observed on a wide range of scales, from the intriguingly regular and well-ordered large-scale field, to much more complex small-scale structures. In this article we shall
Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope
The operation of the solar global dynamo appears to involve many dynamical elements, including the generation of fields by the intense turbulence of the deep convection zone, the transport of these
On the role of meridional flows in flux transport dynamo models
Context. The Sun is a magnetic star whose magnetism and cyclic activity is linked to the existence of an internal dynamo. Aims. We aim to understand the establishment of the solar magnetic 22-yr
The Turbulent Dynamo in Highly Compressible Supersonic Plasmas
The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action
On the interaction between differential rotation and magnetic fields in the Sun
We have performed 3-D numerical simulations of compressible convection under the influence of rotation and magnetic fields in spherical shells. They aim at understanding the subtle coupling between
Stellar Convection and Magnetism across the H-R diagram: Theory and Models
Stars constitute undoublty one of the elementary blocks of the Universe and play as such a central role in determining for instance its chemical evolution. They can be seen as modern physics
We present a method to characterize the spectral transfers of magnetic energy between scales in simulations of stellar convective dynamos. The full triadic transfer functions are computed thanks to
Dynamos in planets, stars and galaxies
Nigel Weiss discusses dynamos in settings as diverse as galaxies and planets in this his 2000 Presidential Address to the Ordinary (A&G) Meeting of the Royal Astronomical Society. Abstract
Shear instabilities in stellar objects : linear stability and non-linear evolution
Shear flows have a significant impact on the dynamics in various astrophysical objects, including accretion discs and stellar interiors. Due to observational limitations the complex dynamics in


On the Origin of Magnetic Fields in the Quiet Photosphere
We consider the possibility that a substantial fraction of the magnetic field in the quiet photosphere is generated locally by dynamo action associated with the granular and supergranular flows. The
Lectures on solar and planetary dynamos
Introduction 1. Fundamentals of dynamo theory P. H. Roberts 2. Solar and stellar dynamics N. O. Weiss 3. Convection and magnetoconvection in a rapidly rotating sphere M. R. E. Proctor 4. Solar
The Granular Magnetic Fields of the Quiet Sun
We report new observations that combine high-precision infrared polarimetry and high-resolution imagery in the visible to demonstrate that most of the quiet solar surface contains a measurable
Helioseismic Studies of Differential Rotation in the Solar Envelope by the Solar Oscillations Investigation Using the Michelson Doppler Imager
The splitting of the frequencies of the global resonant acoustic modes of the Sun by large-scale flows and rotation permits study of the variation of angular velocity Ω with both radius and latitude
Sustaining the Quiet Photospheric Network: The Balance of Flux Emergence, Fragmentation, Merging, and Cancellation
The magnetic field in the solar photosphere evolves as flux concentrations fragment in response to sheared flows, merge when they collide with others of equal polarity, or (partially) cancel against
Cosmical magnetic fields
Magnetic Field Generation in Electrically-Conducting Fluids.By H. K. Moffatt. Pp. 343. (Cambridge University Press: Cambridge and London, 1978.) £15.50.
Chaos in dynamical systems
Preface 1. Introduction and overview 2. One-dimensional maps 3. Strange attractors and fractal dimensions 4. Dynamical properties of chaotic systems 5. Nonattracting chaotic sets 6. Quasiperiodicity