Grant, S.D.T., Jess, D.B., Moreels, M.G. et al. (8 more authors) (2015) Wave Damping Observed in Upwardly Propagating Sausage-mode Oscillations contained within a Magnetic Pore. Astrophysical Journal, 806 (1). 132. ISSN 0004-637X
Abstract
We present observational evidence of compressible MHD wave modes propagating from the solar photosphere through to the base of the transition region in a solar magnetic pore. High cadence images were obtained simultaneously across four wavelength bands using the Dunn Solar Telescope. Employing Fourier and wavelet techniques, sausage-mode oscillations displaying significant power were detected in both intensity and area fluctuations. The intensity and area fluctuations exhibit a range of periods from 181 to 412 s, with an average period ~290 s, consistent with the global p-mode spectrum. Intensity and area oscillations present in adjacent bandpasses were found to be out of phase with one another, displaying phase angles of 6fdg12, 5fdg82, and 15fdg97 between the 4170 Å continuum–G-band, G-band–Na i D1, and Na i D1–Ca ii K heights, respectively, reiterating the presence of upwardly propagating sausage-mode waves. A phase relationship of ~0° between same-bandpass emission and area perturbations of the pore best categorizes the waves as belonging to the "slow" regime of a dispersion diagram. Theoretical calculations reveal that the waves are surface modes, with initial photospheric energies in excess of 35,000 W m−2. The wave energetics indicate a substantial decrease in energy with atmospheric height, confirming that magnetic pores are able to transport waves that exhibit appreciable energy damping, which may release considerable energy into the local chromospheric plasma.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 The American Astronomical Society. All rights reserved. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | magnetohydrodynamics (MHD); Sun: chromosphere; Sun: oscillations; Sun: photosphere |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Automatic Control and Systems Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 19 May 2015 13:24 |
Last Modified: | 26 Mar 2016 10:06 |
Published Version: | http://dx.doi.org/10.1088/0004-637X/806/1/132 |
Status: | Published |
Publisher: | American Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.1088/0004-637X/806/1/132 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:85907 |