• Corpus ID: 117821113

Sign of helicity in the $\alpha$-$\Omega$ geodynamo

@article{Wei2010SignOH,
  title={Sign of helicity in the \$\alpha\$-\$\Omega\$ geodynamo},
  author={Xing Wei},
  journal={arXiv: Earth and Planetary Astrophysics},
  year={2010}
}
  • Xing Wei
  • Published 2 August 2010
  • Geology, Physics
  • arXiv: Earth and Planetary Astrophysics
In this paper we discuss the sign of helicity in the $\alpha$-$\Omega$ dynamo and propose a wave-$\Omega$ model in which the $\alpha$ effect in the geodynamo is induced by helical wave but not helical flow as in the solar dynamo. We then tentatively interpret the mechanisms of the Earth's magnetic westward drift, tilt angle, and dipole reversals. 

References

SHOWING 1-10 OF 23 REFERENCES
A three-dimensional self-consistent computer simulation of a geomagnetic field reversal
A three-dimensional, self-consistent numerical model of the geodynamo is described, that maintains a magnetic field for over 40,000 years. The model, which incorporates a finitely conducting inner
Numerical modeling of the geodynamo: Mechanisms of field generation and equilibration
Numerical calculations of fluid dynamos powered by thermal convection in a rotating, electrically conducting spherical shell are analyzed. We find two regimes of nonreversing, strong field dynamos at
Observation of magnetocoriolis waves in a liquid metal Taylor-Couette experiment.
TLDR
The first observation of fast and slow magnetocoriolis (MC) waves in a laboratory experiment is reported and provides a means for predicting the onset of the magnetorotational instability.
Equatorially Dominated Magnetic Field Change at the Surface of Earth's Core
TLDR
This work analyzed the evolution of nonaxisymmetric magnetic flux at the core surface over the past 400 years and found that the most robust feature is westward motion at 17 kilometers per year, in a belt concentrated around the equator beneath the Atlantic hemisphere.
Rossby waves and α-effect
Rossby waves drifting in the azimuthal direction are a common feature at the onset of thermal convective instability in a rapidly rotating spherical shell. They can also result from the
Free hydromagnetic oscillations of the earth's core and the theory of the geomagnetic secular variation
  • R. Hide
  • Geology, Physics
    Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1966
Free hydromagnetic oscillations of a rotating spherical shell of an incompressible fluid are investigated by means of a simple theoretical model. For each spatial harmonic, rotation gives rise to two
ON THE THEORY OF THE GEODYNAMO
Dynamo action with wave motion.
  • A. Tilgner
  • Physics, Geology
    Physical review letters
  • 2008
It is shown that time dependent velocity fields in a fluid conductor can act as dynamos even when the same velocity fields frozen in at any particular time cannot. This effect is observed in
Rotating spherical Couette flow in a dipolar magnetic field: experimental study of magneto-inertial waves
The magnetostrophic regime, in which Lorentz and Coriolis forces are in balance, has been investigated in a rapidly rotating spherical Couette flow experiment. The spherical shell is filled with
The westward drift of the Earth's magnetic field
The westward drift of the non-dipole part of the earth’s magnetic field and of its secular variation is investigated for the period 1907-45 and the uncertainty of the results discussed. It is found
...
1
2
3
...