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Alfvén Waves (alfvén + wave)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Behaviour of torsional Alfvén waves and field line resonance on rotating magnetars

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2005
Taishi Okita
ABSTRACT Torsional Alfvén waves are likely excited with bursts in rotating magnetars. These waves are probably propagated through corotating atmospheres toward a vacuum exterior. We have studied the physical effects of the azimuthal wavenumber and the characteristic height of the plasma medium on wave transmission. In this work, explicit calculations were carried out based on the three-layered cylindrical model. We found that the coupling strength between the internal shear and the external Alfvén modes is drastically enhanced, when resonance occurs in the corotating plasma cavity. The spatial structure of the electromagnetic fields in the resonance cavity is also investigated when Alfvén waves exhibit resonance. [source]

The problem of phase mixed shear Alfvén waves in the solar corona revisited

ASTRONOMISCHE NACHRICHTEN, Issue 8 2008
G. Mocanu
Abstract The problem of phase mixing of shear Alfvén waves is revisited taking into account dissipative phenomena specific for the solar corona. In regions of space plasmas where the dynamics is controlled by the magnetic field, transport coefficients become anisotropic with transport mechanism having different behavior and magnitude depending on the orientation with respect to the ambient magnetic field. Taking into account realistic values for dissipative coefficients we obtain that the previous results derived in context of torsional Alfvén wave phase mixing are actually heavily underestimated so phase mixing cannot be used to explain the damping of torsional Alfvén waves and heating of open coronal structures. The presented results indicate that in order for phase mixing to still be a viable mechanism to explain heating or wave damping unrealistic assumptions have to be made. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]