Abstracts Details


First Name * : Vaibhav
Last Name * : Pant
Affiliation * : KU Leuven
Abstract Type * : Oral
Title * : MHD simulations and forward modeling of Alfvénic waves in the coronal holes
Author(s) * : Vaibhav Pant, Norbert Magyar, Tom Van Doorsselaere, and Richard Morton
Abstract Session * : Fundamental plasma processes
Abstract * : Several spectroscopic and imaging observations have established the ubiquity of Alfvénic waves in the solar atmosphere. Recently, an apparent discrepancy was noted in the measured Alfvénic wave energy flux in the transition region using SDO/AIA compared to those measured in the corona using Coronal Multi-channel Polarimeter (CoMP). Earlier studies have speculated that this discrepancy could be due to the unresolved wave amplitudes along the line-of-sight (LOS) in the solar atmosphere but they required the use of an additional, unknown source of Alfvénic wave energy to provide agreement with measurements of coronal non-thermal line widths. In this work, I will resolve this discrepancy by presenting 3D MHD simulations of propagating Alfvénic waves in a gravitationally stratified plasma with properties similar to the coronal holes in the Sun. I will discuss the correlation between Doppler velocities and non-thermal line widths derived using the forward modeling of the Alfvénic waves. I will present the variation of Doppler velocities and non-thermal line widths with height above the solar atmosphere. Furthermore, I will compare the amount of underestimation of true energy in the MHD simulations due to LOS superposition of different structures in the solar corona. Finally, I will discuss the asymmetry in the emission line produced by the Alfvénic waves in the solar atmosphere.