MHD simulations and the morphology of spicular solar jets

Fionnlagh Mackenzie Dover

Hosted by Solar Physics and Space Plasma Research Centre (SP2RC), University of Sheffield, UK on December 17, 2020

Abstract

Solar spicules are one of the dominant dynamic phenomena of the lower solar atmosphere. Here, we show our results on modelling the propagation of such localised jets driven by a momentum pulse as the exciting force near photospheric heights. Using the MPI-AMRVAC code to perform 2D MHD simulations in an idealised stratified solar atmosphere, we investigate how key parameters (e.g., driver time, equilibrium magnetic field strength, velocity amplitude of driver and tilt with respect to the magnetic field) determine the morphology of these small-scale solar jets. A parametric study is carried out and using jet tracking software we analyse the jet properties (e.g., widths, apex heights, etc). We find that jet boundary deformation occurs naturally due to speeds involved in driving these jets within the range of spicule heights that could be then a possible alternative explanation for the appearance of transverse motions (both axisymmetric and non-axisymmetric deformations). By resolving structures up to 10 km, we also find unforeseen substructures inside the spicular jet beam. We propose observers to confirm this latter finding that may be challenging due to current spatial resolution limits.