Effects of Fieldline Topology on Energy Propagation in the Corona

TL;DR

This study examines how different magnetic field topologies in the solar corona influence energy transfer and dissipation caused by footpoint motions, highlighting the role of null points and separatrix layers in energy propagation.

Contribution

It provides new insights into how magnetic nulls and topological features affect energy propagation and dissipation in the solar corona.

Findings

Magnetic nulls and separatrix layers significantly alter energy propagation.

Energy is either trapped or freely propagates depending on magnetic topology.

Boundary motions initially increase magnetic and kinetic energy.

Abstract

We study the effect of photospheric footpoint motions on magnetic field structures containing magnetic nulls. The footpoint motions are prescribed on the photospheric boundary as a velocity field which entangles the magnetic field. We investigate the propagation of the injected energy, the conversion of energy, emergence of current layers and other consequences of the non-trivial magnetic field topology in this situation. These boundary motions lead initially to an increase in magnetic and kinetic energy. Following this, the energy input from the photosphere is partially dissipated and partially transported out of the domain through the Poynting flux. The presence of separatrix layers and magnetic null-points fundamentally alters the propagation behavior of disturbances from the photosphere into the corona. Depending on the field line topology close to the photosphere, the energy is either trapped or free to propagate into the corona.