Journal ArticleDOI
Wave propagation in a magnetic cylinder
P. M. Edwin,B. Roberts +1 more
TLDR
In this article, the authors investigated the nature of oscillations in a magnetic cylinder embedded in magnetic environment and showed that the standard slender flux tube analysis of a kink mode in a cylinder excludes the possibility of a second mode, which arises under photospheric conditions.Abstract:
The nature of oscillations in a magnetic cylinder embedded in a magnetic environment is investigated. It is shown that the standard slender flux tube analysis of a kink mode in a cylinder excludes the possibility of a second mode, which arises under photospheric conditions. Under coronal conditions, two widely separated classes of oscillation can be freely sustained, one on an acoustic time-scale and the other on an Alfvenic time-scale. The acoustic-type oscillations are always present, but the much shorter period, Alfvenic-type, oscillations arise only in high density (strictly, low Alfven velocity) loops. An application to waves in fibrils is also given, and suggests (following Wentzel, 1979) that they are fast kink waves propagating in a density enhancement.read more
Citations
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Magnetohydrodynamic waves and coronal seismology: an overview of recent results
TL;DR: Four topics are focused on: the current controversy surrounding propagating intensity perturbations along coronal loops, the interpretation of propagating transverse loop oscillations, the ongoing search for coronal (torsional) Alfvén waves, and the rapidly developing topic of quasi-periodic pulsations in solar flares.
Journal ArticleDOI
Small-scale solar magnetic fields: An overview
TL;DR: An overview of the observational and the theoretical methods used to investigate solar magnetic fields is given in this paper, which includes an introduction to the Stokes parameters, their radiative transfer in the presence of a magnetic field, and empirical techniques used to measure various properties of solar magnetic features.
Journal ArticleDOI
Coronal loop oscillations - An interpretation in terms of resonant absorption of quasi-mode kink oscillations
TL;DR: In this paper, the authors used the theoretical expressions for the decay time by Hollweg & Yang and Ruderman & Roberts to estimate the ratio of the length scale of inhomogeneity compared to the loop radius for a collection of loop oscillations.
Journal ArticleDOI
Quasi-Periodic Pulsations in Solar Flares
TL;DR: In this paper, a review of the physical mechanisms responsible for the generation of long quasi-periodic pulsations (QPPs) is presented, with the focus on QPPs with the periods longer than one second.
Journal ArticleDOI
MHD Waves and Coronal Seismology: an overview of recent results
TL;DR: In this paper, the authors give a brief review of some aspects of MHD waves and coronal seismology which have recently been the focus of intense debate or are newly emerging, focusing on four topics: (i) the current controversy surrounding propagating intensity perturbations along coronal loops, (ii) the interpretation of propagating transverse loop oscillations,
References
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Journal ArticleDOI
Elastic Waves in Layered Media
TL;DR: In this paper, Elastic Waves in Layered Media (ELMW) are used to describe the properties of layered media in a geologiska foreningen i Stockholm Forhandlingar.
Journal ArticleDOI
Wave propagation in a magnetically structured atmosphere
TL;DR: In this paper, the authors investigate the occurrence of magnetoacoustic surface waves at a single magnetic interface and consider in detail the case where one side of the interface is field-free.
Journal ArticleDOI
Wave propagation in a magnetically structured atmosphere: III: The slab in a magnetic environment
P.M. Edwin,B. Roberts +1 more
TL;DR: In this paper, the propagation of waves in a magnetic slab embedded in magnetic environment is investigated and possible modes of propagation are examined from the general dispersion relation, both analytically and numerically, for disturbances which are evanescent in the environment.