Magnetic Helicity Evolution During the Solar Activity Cycle: Observations and Dynamo Theory
arXiv:astro-ph/0304232 · doi:10.1051/0004-6361:20031126
Abstract
We study a simple model for the solar dynamo in the framework of the Parker migratory dynamo, with a nonlinear dynamo saturation mechanism based on magnetic helicity conservation arguments. We find a parameter range in which the model demonstrates a cyclic behaviour with properties similar to that of Parker dynamo with the simplest form of algebraic alpha-quenching. We compare the nonlinear current helicity evolution in this model with data for the current helicity evolution obtained during 10 years of observations at the Huairou Solar Station of China. On one hand, our simulated data demonstrate behaviour comparable with the observed phenomenology, provided that a suitable set of governing dynamo parameters is chosen. On the other hand, the observational data are shown to be rich enough to reject some other sets of governing parameters. We conclude that, in spite of the very preliminary state of the observations and the crude nature of the model, the idea of using observational data to constrain our ideas concerning magnetic field generation in the framework of the solar dynamo appears promising.
10 pages, 3 Postscript figures, uses aa.cls
References in corpus (14)
- Dynamic nonlinearity in large scale dynamos with shear
- Doubly Helical Coronal Ejections from Dynamos and their Role in Sustaining the Solar Cycle
- The Magnetic Power Spectrum in Faraday Rotation Screens
- Local and nonlocal magnetic diffusion and alpha-effect tensors in shear flow turbulence
- Magnetic Helicity Tensor for an Anisotropic Turbulence
- The Role of Magnetic Helicity Transport in Nonlinear Galactic Dynamos
- Nonlinear Alpha Effect in Dynamo Theory
- Magnetic helicity in stellar dynamos: new numerical experiments
- Large scale dynamos with helicity loss through boundaries
- Nonlinear Magnetic Diffusion and Magnetic Helicity Transport in Galactic Dynamos
- Nonlinear Turbulent Magnetic Diffusion and Mean-Field Dynamo
- Levels of chromospheric and coronal activity in Sun-like stars and various types of dynamo waves
- Kinematic dynamo wave in the vicinity of the solar poles
- Effects of boundary conditions on the dynamics of the solar convection zone
Cited by in corpus (42)
- Astrophysical magnetic fields and nonlinear dynamo theory
- The case for a distributed solar dynamo shaped by near-surface shear
- The solar magnetic field
- Cross helicity and related dynamo
- Magnetic fluctuations and formation of large-scale inhomogeneous magnetic structures in a turbulent convection
- New dynamo pattern revealed by solar helical magnetic fields
- Strong mean field dynamos require supercritical helicity fluxes
- The Radial Distribution of Magnetic Helicity in the Solar Convective Zone: Observations and Dynamo Theory
- The mean electro-motive force, current- and cross-helicity under the influence of rotation, magnetic field and shear
- Current helicity of active regions as a tracer of large-scale solar magnetic helicity
- Cross helicity and turbulent magnetic diffusivity in the solar convection zone
- Evolution and Distribution of Current Helicity in Full-Sun Simulations
- The distribution of current helicity at the solar surface at the beginning of the solar cycle
- Magnetic concentrations in stratified turbulence: the negative effective magnetic pressure instability
- Nonlinear Solar Dynamo Model with Magnetic Helicity
- The origin of the helicity hemispheric sign rule reversals in the mean-field solar-type dynamo
- The dynamics of Wolf numbers based on nonlinear dynamo with magnetic helicity: comparisons with observations
- Polar branches of stellar activity waves: dynamo models and observations
- Analysis on Correlations between Subsurface Kinetic Helicity and Photospheric Current Helicity in Active Regions
- The mean tilt of sunspot bipolar regions: theory, simulations and comparison with observations
- Large Scale Soft X-ray Loops And Their Magnetic Chirality In Both Hemispheres
- Current Helicity and Twist as Two Indicators of The Mirror Asymmetry of solar Magnetic Fields
- Turbulent magnetic helicity fluxes in solar convective zone
- Triad interactions and the bidirectional turbulent cascade of magnetic helicity
- Dependence of stellar magnetic activity cycles on rotational period in nonlinear solar-type dynamo
- Small-scale magnetic buoyancy and magnetic pumping effects in a turbulent convection
- Turbulent cross-helicity in the mean-field solar dynamo problem
- Nonlinear shear-current dynamo and magnetic helicity transport in sheared turbulence
- A new simple dynamo model for stellar activity cycle
- Nonlinear mean-field dynamo and prediction of solar activity
- A global two-scale helicity proxy from -ambiguous solar magnetic fields
- From Polarimetry to Helicity: Studies of Solar Magnetic Fields at the Huairou Solar Observing Station
- Large Scale Properties of Tilt of Sunspot Groups and Joy's Law Near The Solar Equator
- Budget equations and astrophysical nonlinear mean-field dynamos
- Magnetic fields of low-mass main sequences stars: Nonlinear dynamo theory and mean-field numerical simulations
- Nonlinear and chaotic resonances in solar activity
- Nonlinear turbulent magnetic diffusion and effective drift velocity of large-scale magnetic field in a two-dimensional magnetohydrodynamic turbulence
- Current helicity and electromotive force of magnetoconvection influenced by helical background fields
- Magnetic bipoles in rotating turbulence with coronal envelope
- Statistical distribution of current helicity in solar active regions over the magnetic cycle
- Estimates of current helicity and tilt of solar active regions and Joy's law
- Solar cycle asymmetry as a consequence of fluctuations in dynamo parameters