Influence of the Lower Atmosphere on Wave Heating and Evaporation in Solar Coronal Loops

Abstract

We model a coronal loop as a 3D magnetic cylinder in a realistic solar atmosphere that extends from the chromosphere to the corona. Kink oscillations, believed to be ubiquitous in the solar corona, are launched in the loop. Heating is expected owing to the dissipation of wave energy at small structures that develop from the Kelvin–Helmholtz instability induced by kink oscillations. Increases in temperature and internal energy can be observed in the coronal counterpart of the driven loop. With the presence of thermal conduction, chromospheric evaporation can also be seen. Although the volume-averaged temperature and density changes seem slight (∼4% relative to a nondriven loop), the enthalpy flow from the lower atmosphere redistributes the density and temperature in the vertical direction, thus enhancing the dissipation of wave energy in the corona. The efficient heating in the coronal counterpart of the loop can complement the thermal conductive losses shown in the current model and thus maintain the internal energy in the corona.

Keywords

• Magnetohydrodynamics
• Solar coronal waves