Can magnetic breakout be achieved from multiple flux emergence?

School of Mathematics and Statistics, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, UK e-mail: dm428@st-andrews.ac.uk

Received: 28 January 2009
Accepted: 5 March 2009

Abstract

Aims. We study the breakout model using multiple flux emergence to produce the magnetic configuration and the trigger. We do not impose any artificial motions on the boundaries. Once the original flux tube configuration is chosen the system is left to evolve itself.

Methods. We perform non-linear simulations in 2.5D by solving the compressible and resistive MHD equations using a Lagrangian remap, shock capturing code (Lare2D). To produce a quadrupolar configuration from flux emergence we build on previous work where the interaction of two flux tubes forms the required quadrupole. Instead of imposing a shearing flow, a third flux tube is then allowed to emerge up through the central arcade.

Results. Breakout is not achieved in any of the experiments. This is due to the interaction of the third tube with the quadrupole and the effect of the plasma β being  at the photosphere and β in the solar interior. When β is of these orders, flows generated in the plasma can influence the magnetic field and so photospheric footpoints do not remain fixed.