WAVE DAMPING OBSERVED IN UPWARDLY PROPAGATING SAUSAGE-MODE OSCILLATIONS CONTAINED WITHIN A MAGNETIC PORE

Journal Article · Wed Jun 10 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/806/1/132· OSTI ID:22522293

Grant, S. D. T.; Jess, D. B.; Keys, P. H. ^[1]; Moreels, M. G.; Doorsselaere, T. Van ^[2]; Morton, R. J. ^[3]; Christian, D. J. ^[4]; Giagkiozis, I.; Verth, G.; Erdélyi, R. ^[5]

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1. Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom)
2. Center for mathematical Plasma Astrophysics, Mathematics Department, KU Leuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium)
3. Mathematics and Information Sciences, Northumbria University, Newcastle Upon Tyne NE1 8ST (United Kingdom)
4. Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330 (United States)
5. Solar Physics and Space Plasma Research Centre (SPRC), The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

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 6.°12, 5.°82, and 15.°97 between the 4170 Å continuum–G-band, G-band–Na i D{sub 1}, and Na i D{sub 1}–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{sup −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.

• OSTI ID: 22522293
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 806; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CHROMOSPHERE
DAMPING
DIAGRAMS
EMISSION SPECTRA
FLUCTUATIONS
MAGNETOHYDRODYNAMICS
OSCILLATION MODES
OSCILLATIONS
PHOTOSPHERE
PLASMA
SUN
TELESCOPES