Modelling of explosive events in the solar transition region in a 2D environment

I. General reconnection jet dynamics

¹ Armagh Observatory, College Hill, Armagh, BT61 9DG, N. Ireland e-mail: ilr@star.arm.ac.uk; jgd@star.arm.ac.uk
² School of Mathematics and Statistics, University of St. Andrews, St Andrews, Fife KY16 9SS, Scotland e-mail: klaus@mcs.st-and.ac.uk
³ Space & Atmosphere Research Center, Dept. of Applied Mathematics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, UK

Corresponding author: R. Erdélyi, Robertus@sheffield.ac.uk

Received: 13 October 2000
Accepted: 23 January 2001

Abstract

The aim of the present study is to investigate the reconnection jets formed during the process of magnetic flux cancellation in the physical environment of the solar transition region. The emission properties of these jets are then computed for two resonance transition region lines, C iv 1548.2 Åand O vi 1031.9 Å, under the assumption of non-equilibrium ionization. The numerical modelling involves 2-dimensional (2D) dissipative, radiative, nonlinear magnetohydrodynamics. The nonlinear anisotropic thermal conduction, radiative losses, and volumetric heating are taken into account in order to assess their role in the physical situation examined. This work is a continuation of previous related simulations where small-scale energy depositions were modelled in 1D radiative hydrodynamics. Having an X-point reconnection in the mid-transition region gives blue-shifts of the order of ~100 km s^-1, however, the red-shift can be up to one order of magnitude less.