The Role of High-frequency Transverse Oscillations in Coronal Heating

Abstract

Transverse oscillations that do not show significant damping in solar coronal loops are found to be ubiquitous. Recently, the discovery of high-frequency transverse oscillations in small-scale loops has been accelerated by the Extreme Ultraviolet Imager on board Solar Orbiter. We perform a meta-analysis by considering the oscillation parameters reported in the literature. Motivated by the power law of the velocity power spectrum of propagating transverse waves detected with CoMP, we consider the distribution of energy fluxes as a function of oscillation frequencies and the distribution of the number of oscillations as a function of energy fluxes and energies. These distributions are described as a power law. We propose that the power-law slope ( δ = −1.40) of energy fluxes depending on frequencies could be used for determining whether high-frequency oscillations dominate the total heating ( δ 1). In addition, we found that the oscillation number distribution depending on energy fluxes has a power-law slope of α = 1.00, being less than 2, which means that oscillations with high energy fluxes provide the dominant contribution to the total heating. It is shown that, on average, higher energy fluxes are generated from higher-frequency oscillations. The total energy generated by transverse oscillations ranges from about 10 ^20 to 10 ^25 erg, corresponding to the energies for nanoflare (10 ^24 –10 ^27 erg), picoflare (10 ^21 –10 ^24 erg), and femtoflare (10 ^18 –10 ^21 erg). The respective slope results imply that high-frequency oscillations could provide the dominant contribution to total coronal heating generated by decayless transverse oscillations.

Keywords

• Solar coronal heating
• Solar oscillations
• Solar coronal waves