Slow magneto-acoustic waves in simulations of a solar plage region carry enough energy to heat the chromosphere

Abstract

We study the properties of slow magneto-acoustic waves that are naturally excited due to turbulent convection and investigate their role in the energy balance of a plage region using three dimensional (3D) radiation-MHD simulations. We calculate the horizontally averaged (over the whole domain) frequency power spectra for both longitudinal and vertical (i.e. the component perpendicular to the surface) components of velocity. To compare our results with the observations we degrade the simulation data with Gaussian kernels having FWHM of 100 km and 200 km, and calculate horizontally averaged power spectra for the vertical component of velocity. The power spectra of the longitudinal component of velocity, averaged over field lines in the core of a kG magnetic flux concentration, reveal that the dominant period of oscillations shifts from around 6.5 minutes in the photosphere to around 4 minutes in the chromosphere. At the same time, the velocity power spectra, averaged horizontally over the whole domain, show that low frequency waves (approximately 6.5 minute period) may reach well into the chromosphere. Importantly, waves with frequencies above 5 mHz propagating along different field lines are found to be out of phase with each other even within a single magnetic concentration. The horizontally averaged power spectra of the vertical component of velocity at various effective resolutions show that the observed acoustic wave energy fluxes are underestimated, by a factor of three even if determined from observations carried out at a high spatial resolution of 200 km. Our results show that longitudinal waves carry (just) sufficient energy to heat the chromosphere in solar plage. We conjecture that current observations (with spatial resolution around 200 km) underestimate the energy flux by roughly a factor of three, or more if the observations have lower spatial resolution.

Accepted for publication in A & A

References in corpus (17)

• Numerical simulations of quiet Sun magnetism: On the contribution from a small-scale dynamo
• The solar magnetic field
• Dynamic Fibrils are driven by Magnetoacoustic Shocks
• High Resolution Observations and Modeling of Dynamic Fibrils
• Extension of the MURaM radiative MHD code for coronal simulations
• Channeling 5-min photospheric oscillations into the solar outer atmosphere through small-scale vertical magnetic flux tubes
• The solar chromosphere at high resolution with IBIS. II. Acoustic shocks in the quiet internetwork and the role of magnetic fields
• Dynamics of the solar magnetic bright points derived from their horizontal motions
• Structure and Dynamics of Isolated Internetwork Ca II H Bright Points Observed by Sunrise
• High-frequency Oscillations in Small Magnetic Elements Observed with Sunrise/SuFI
• Vortex Flow Properties in Simulations of Solar Plage Region: Evidence for their role in chromospheric heating
• Simulations Show that Vortex Flows could Heat the Chromosphere in Solar Plage
• High-Frequency Oscillations in a Solar Active Region observed with the Rapid Dual Imager
• Chromospheric and Coronal Wave Generation in a Magnetic Flux Sheath
• Numerical determination of the cutoff frequency in solar models
• Influence of the Magnetic Field on Oscillation Spectra in Solar Faculae
• IRIS observations of chromospheric heating by acoustic waves in solar quiet and active regions

Cited by in corpus (4)

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