منابع مشابه
A Vorticity-magnetic Field Dynamo Instability
We generalize the mean field magnetic dynamo to include local evolution of the mean vorticity in addition to the mean magnetic field. The coupled equations exhibit a general mean field dynamo instability that enables the transfer of turbulent energy to the magnetic field and vorticity on larger scales. The growth of the vorticity and magnetic field both require helical turbulence which can be s...
متن کاملDynamo Theory and Earth’s Magnetic Field
The Earth’s magnetic field belongs in that class of physical phenomena which are commonplace yet also very complex. It is commonplace in that almost everyone knows that it exists, yet not very many people (probably including a good percentage of physicists) know how it works. The theory behind the generation of a magnetic field, known as dynamo theory, is still an active area of research. The e...
متن کاملCoexisting stochastic and coherence resonance in a mean-field dynamo model for Earth’s magnetic field reversals
Using a spherical symmetric mean field α-dynamo model for Earth’s magnetic field reversals, we show the coexistence of the noise-induced phenomena coherence resonance and stochastic resonance. Stochastic resonance has been recently invoked to explain the 100 kyr periodicity in the distribution of the residence time between reversals. The comparison of the resulting residence time distribution w...
متن کاملSmall-scale magnetic helicity losses from a mean-field dynamo
Using mean-field models with a dynamical quenching formalism, we show that in finite domains magnetic helicity fluxes associated with small-scale magnetic fields are able to alleviate catastrophic quenching. We consider fluxes that result from advection by a mean flow, the turbulent mixing down the gradient of mean small-scale magnetic helicity density or the explicit removal which may be assoc...
متن کاملStrong horizontal photospheric magnetic field in a surface dynamo simulation
Context. Observations with the Hinode spectro-polarimeter have revealed strong horizontal internetwork magnetic fields in the quiet solar photosphere. Aims. We aim at interpreting the observations by means of results from numerical simulations. Methods. Radiative MHD simulations of dynamo action by near-surface convection are analyzed with respect to the relation between vertical and horizontal...
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ژورنال
عنوان ژورنال: Icarus
سال: 2014
ISSN: 0019-1035
DOI: 10.1016/j.icarus.2014.06.020