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Title: PROPAGATION AND DISPERSION OF SAUSAGE WAVE TRAINS IN MAGNETIC FLUX TUBES

Abstract

A localized perturbation of a magnetic flux tube produces wave trains that disperse as they propagate along the tube, where the extent of dispersion depends on the physical properties of the magnetic structure, on the length of the initial excitation, and on its nature (e.g., transverse or axisymmetric). In Oliver et al. we considered a transverse initial perturbation, whereas the temporal evolution of an axisymmetric one is examined here. In both papers we use a method based on Fourier integrals to solve the initial value problem. We find that the propagating wave train undergoes stronger attenuation for longer axisymmetric (or shorter transverse) perturbations, while the internal to external density ratio has a smaller effect on the attenuation. Moreover, for parameter values typical of coronal loops axisymmetric (transverse) wave trains travel at a speed 0.75–1 (1.2) times the Alfvén speed of the magnetic tube. In both cases, the wave train passage at a fixed position of the magnetic tube gives rise to oscillations with periods of the order of seconds, with axisymmetric disturbances causing more oscillations than transverse ones. To test the detectability of propagating transverse or axisymmetric wave packets in magnetic tubes of the solar atmosphere (e.g., coronal loops, spicules,more » or prominence threads) a forward modeling of the perturbations must be carried out.« less

Authors:
;  [1];  [2]
  1. Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)
  2. School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)
Publication Date:
OSTI Identifier:
22522340
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 806; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALFVEN WAVES; ATTENUATION; AXIAL SYMMETRY; DENSITY; DISTURBANCES; EXCITATION; MAGNETIC FIELDS; MAGNETIC FLUX; OSCILLATIONS; SOLAR CORONA; SOLAR PROMINENCES; SUN; VELOCITY; WAVE PACKETS; WAVE PROPAGATION

Citation Formats

Oliver, R., Terradas, J., and Ruderman, M. S., E-mail: ramon.oliver@uib.es. PROPAGATION AND DISPERSION OF SAUSAGE WAVE TRAINS IN MAGNETIC FLUX TUBES. United States: N. p., 2015. Web. doi:10.1088/0004-637X/806/1/56.
Oliver, R., Terradas, J., & Ruderman, M. S., E-mail: ramon.oliver@uib.es. PROPAGATION AND DISPERSION OF SAUSAGE WAVE TRAINS IN MAGNETIC FLUX TUBES. United States. doi:10.1088/0004-637X/806/1/56.
Oliver, R., Terradas, J., and Ruderman, M. S., E-mail: ramon.oliver@uib.es. Wed . "PROPAGATION AND DISPERSION OF SAUSAGE WAVE TRAINS IN MAGNETIC FLUX TUBES". United States. doi:10.1088/0004-637X/806/1/56.
@article{osti_22522340,
title = {PROPAGATION AND DISPERSION OF SAUSAGE WAVE TRAINS IN MAGNETIC FLUX TUBES},
author = {Oliver, R. and Terradas, J. and Ruderman, M. S., E-mail: ramon.oliver@uib.es},
abstractNote = {A localized perturbation of a magnetic flux tube produces wave trains that disperse as they propagate along the tube, where the extent of dispersion depends on the physical properties of the magnetic structure, on the length of the initial excitation, and on its nature (e.g., transverse or axisymmetric). In Oliver et al. we considered a transverse initial perturbation, whereas the temporal evolution of an axisymmetric one is examined here. In both papers we use a method based on Fourier integrals to solve the initial value problem. We find that the propagating wave train undergoes stronger attenuation for longer axisymmetric (or shorter transverse) perturbations, while the internal to external density ratio has a smaller effect on the attenuation. Moreover, for parameter values typical of coronal loops axisymmetric (transverse) wave trains travel at a speed 0.75–1 (1.2) times the Alfvén speed of the magnetic tube. In both cases, the wave train passage at a fixed position of the magnetic tube gives rise to oscillations with periods of the order of seconds, with axisymmetric disturbances causing more oscillations than transverse ones. To test the detectability of propagating transverse or axisymmetric wave packets in magnetic tubes of the solar atmosphere (e.g., coronal loops, spicules, or prominence threads) a forward modeling of the perturbations must be carried out.},
doi = {10.1088/0004-637X/806/1/56},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 806,
place = {United States},
year = {2015},
month = {6}
}