Tracking the Alfven Waves in Closed Coronal Structure

Alfvén waves are potential candidates to explain the heating of the solar corona, since they can propagate long distances from the source where they originate up to the corona without significant damping. They are believed to be driven by the turbulent convective motions in the photosphere, and predominantly propagate upwards into the corona along network magnetic fields. However, the mechanism by which they convert their energy into plasma heating is still under debate. One scenario is that counter propagating Alfvén waves can interact nonlinearly and create turbulence. Energy cascades from the larger scales to small scale where it can be dissipated, e.g., by viscosity and resistivity. To date, observations of Alfvénic waves in the corona have been limited. The Coronal Multi-Channel Polarimeter (CoMP) provides remote observations of the off-limb corona, and has revealed Alfvénic velocity fluctuations are ubiquitous. The observations are currently limited to examining parallel wavenumbers, with the velocity power spectral density displaying power law behaviour that possess a range of spectral indices across the corona. The slope of the power spectra is related to the parallel correlation time of the waves in the corona. Given that the photospheric motions should have the same correlation time across the Sun (maybe with the exception of active regions), this may indicate that the different coronal spectral indices are the results of different magnetic/plasma conditions influencing the evolution of the waves through the lower solar atmosphere. Here, we present results on how Alfvén waves are influenced by different magnetic field conditions using a Reduced Magneto Hydrodynamic (RMHD) model which incorporates the wave turbulence and describes the propagation and dissipation of Alfvén waves along a single flux tube.