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

II. Various MHD experiments

¹ High Altitude Observatory, NCAR, 3450 Mitchell Lane, Boulder, CO 80301, USA e-mail: ilr@ucar.edu
² Armagh Observatory, College Hill, Armagh, BT61 9DG, N. Ireland e-mail: ilr@star.arm.ac.uk; jgd@star.arm.ac.uk
³ School of Mathematics and Statistics, University of St. Andrews, St Andrews, Fife KY16 9SS, Scotland e-mail: klaus@mcs.st-and.ac.uk
⁴ Space & Atmosphere Research Center, Dept. of Applied Mathematics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, England

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

Received: 7 March 2001
Accepted: 28 May 2001

Abstract

We examine the response of various physical environments representing the solar atmosphere to a magnetic reconnection event. The reconnection is driven by a localized increase of the magnetic diffusivity in the current concentration formed between two magnetic fluxes of opposite polarity. The time dependent evolution is then followed by numerically solving the 2-dimensional (2D) dissipative magnetohydrodynamic (MHD) equations, including also effects of thermal conduction, radiative losses, and volumetric heating. This work continues a previous related study (Roussev et al. 2001a), and compares results obtained from exploring different initial states. The choice of the initial states is found to be crucial to the dynamics of the reconnection jets. The numerical experiments are aimed at modelling transient events on the quiet Sun, with an emphasis on explosive events. The 2D reconnection experiments presented in this paper are the basis for a detailed analysis on the line synthesis in transition region resonant lines, presented by Roussev et al. ([CITE]).