The study of turbulence in the chromosphere using a two-fluid approach and adaptive mesh refinement

The aim of this study is the understanding of the mechanism of formation and the evolution of the spicules in the solar chromosphere. Spicules are highly dynamic chromospheric material that rise into the corona. Latest observations showed spicules (called type II spicules) with very high velocities of 50-100 km/s with very short timescales of less than 100 s. Because of the shear flow and high velocities, the spicules enter shortly after formation in the turbulent regime, and it is believed that they have a great contribution to the coronal heating.The chromosphere is a partially ionized medium and, as the density drops with height in the solar atmosphere, the collisional coupling between charges and neutrals also decreases.Theoretical studies and observations showed that the two-fluid effects cannot be neglected in the chromosphere.Studies based on numerical simulations of type II spicules showed that the interaction between neutrals and ions could be a key ingredient in the formation of the spicules.In order to study the turbulence very good resolution is needed in order to resolve the dissipation scales. In particular, for the study of type II spicules, which evolve on very short time and space scales, extremely high resolution is needed.From a computational point of view, this is best achieved using an adaptive mesh refinement (AMR).In this work we want to use a two-fluid code with AMR capabilities in order to study the spicules in the upper chromosphere.

Keywords:turbulence, two-fluid, AMR, RTI, spicules

Disciplines:Space plasma physics and solar physics