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Propagating wave phenomena detected in observations and simulations of the lower solar atmosphere

journal contribution
posted on 2012-02-20, 00:00 authored by D B Jess, Sergiy ShelyagSergiy Shelyag, M Mathioudakis, P H Keys, D J Christian, F P Keenan
We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magnetohydrodynamic (MHD) code, respectively. Each data set demonstrates a wealth of magnetoacoustic oscillatory behavior, visible as periodic intensity fluctuations with periods in the range 110-600 s. Almost no propagating waves with periods less than 140 s and 110 s are detected in the observational and simulated data sets, respectively. High concentrations of power are found in highly magnetized regions, such as magnetic bright points and intergranular lanes. Radiative diagnostics of the photospheric simulations replicate our observational results, confirming that the current breed of MHD simulations are able to accurately represent the lower solar atmosphere. All observed oscillations are generated as a result of naturally occurring magnetoconvective processes, with no specific input driver present. Using contribution functions extracted from our numerical simulations, we estimate minimum G-band and 4170 Å continuum formation heights of 100km and 25km, respectively. Detected magnetoacoustic oscillations exhibit a dominant phase delay of -8° between the G-band and 4170 Å continuum observations, suggesting the presence of upwardly propagating waves. More than 73% of MBPs (73% from observations and 96% from simulations) display upwardly propagating wave phenomena, suggesting the abundant nature of oscillatory behavior detected higher in the solar atmosphere may be traced back to magnetoconvective processes occurring in the upper layers of the Sun's convection zone.

History

Journal

Astrophysical journal

Volume

746

Issue

2

Article number

183

Pagination

1 - 12

Publisher

IOP Publishing

Location

Bristol, Eng.

ISSN

0004-637X

eISSN

1538-4357

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2012, The American Astronomical Society