Observations of ubiquitous compressive waves in the Sun’s chromosphere

Abstract

The details of the mechanism(s) responsible for the observed heating and dynamics of the solar atmosphere still remain a mystery. Magnetohydrodynamic waves are thought to have a vital role in this process. Although it has been shown that incompressible waves are ubiquitous in off-limb solar atmospheric observations, their energy cannot be readily dissipated. Here we provide, for the first time, on-disk observation and identification of concurrent magnetohydrodynamic wave modes, both compressible and incompressible, in the solar chromosphere. The observed ubiquity and estimated energy flux associated with the detected magnetohydrodynamic waves suggest the chromosphere is a vast reservoir of wave energy with the potential to meet chromospheric and coronal heating requirements. We are also able to propose an upper bound on the flux of the observed wave energy that is able to reach the corona based on observational constraints, which has important implications for the suggested mechanism(s) for quiescent coronal heating.

Hi-C and AIA observations of transverse magnetohydrodynamic waves in active regions

“…In particular the periodic, transverse displacement of magnetic flux tubes in both the chromosphere (De Pontieu et al 2007; Kuridze et al 2012;Morton et al 2012) and in the corona (Tomczyk et al 2007;Erdélyi & Taroyan 2008). The chromospheric motions are somewhat better resolved as they are observed with high-resolution (<0.…”

The dynamical behaviour of a jet in an on-disk coronal hole observed with AIA/SDO

“…Morton et al 2012b), providing the data noise as errors for the fitting. The Gaussian centroid is taken as the central position of the jets axis, and to the associated errors from the fit we add the estimated remaining displacement error.…”

Energy and energy flux in axisymmetric slow and fast waves

“…A&A 578, A60 (2015) In this paper we focus on axisymmetric slow and fast sausage modes, which have recently been discovered in numerous structures, but have not been adequately modelled to estimate their energy content. They have been detected in coronal loops (De Moortel et al 2000;Wang et al 2002Wang et al , 2003Krishna Prasad et al 2012), in photospheric pores (Dorotovič et al 2008(Dorotovič et al , 2014Morton et al 2011;Moreels et al 2015), in network bright points (McAteer et al 2003;Bharti et al 2006;Martínez González et al 2011), in flares (Nakariakov et al 2003;Melnikov et al 2005;Van Doorsselaere et al 2011), and in the chromosphere (Morton et al 2012a). Some authors have attempted to estimate the amount of energy present in these observations.…”

“…Some authors have attempted to estimate the amount of energy present in these observations. Morton et al (2012a) have observed both sausage and kink modes in the chromosphere and used MHD theory to estimate the energy in the waves. They found that the energy of compressive (sausage) waves was higher than the energy in transverse waves.…”