Propagating Wave Phenomena Detected in Observations and Simulations of the Lower Solar Atmosphere

TL;DR

This study combines high-cadence observations and simulations to analyze magneto-acoustic oscillations in the lower solar atmosphere, revealing their origins in magnetoconvective processes and their upward propagation.

Contribution

It demonstrates that current magneto-hydrodynamic simulations accurately replicate observed oscillatory phenomena in the solar photosphere, linking them to natural magnetoconvective processes.

Findings

Oscillations have periods between 110-600 s, with fewer waves below 140s.

High power concentrations are found in magnetized regions like bright points.

Over 73% of magnetic bright points show upward wave propagation.

Abstract

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 magneto-hydrodynamic code, respectively. Each dataset demonstrates a wealth of magneto-acoustic oscillatory behaviour, visible as periodic intensity fluctuations with periods in the range 110-600 s. Almost no propagating waves with periods less than 140s and 110s are detected in the observational and simulated datasets, respectively. High concentrations of power are found in highly magnetised 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 magneto-hydrodynamic 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 Angstrom continuum formation heights of 100 km and 25 km, respectively. Detected magneto-acoustic oscillations exhibit a dominant phase delay of -8 degrees between the G-band and 4170 Angstrom continuum observations, suggesting the presence of upwardly propagating waves. More than 73% of MBPs (73% from observations, 96% from simulations) display upwardly propagating wave phenomena, suggesting the abundant nature of oscillatory behaviour detected higher in the solar atmosphere may be traced back to magnetoconvective processes occurring in the upper layers of the Sun's convection zone.