Eur. Phys. J. D (2017) 71: 51
https://doi.org/10.1140/epjd/e2017-70568-1

Regular Article

Blinkers in the solar transition region

¹ Mathematical Institute, University of Oxford, 24-29 St Giles’, Oxford OX1 3LB, UK
² Merton College, University of Oxford, Merton Street, Oxford OX1 4JD, UK

^a e-mail: jmaa@seh.ox.ac.uk

Received: 7 September 2016
Received in final form: 27 November 2016
Published online: 2 March 2017

Abstract

In this paper it is shown that the small flare-like patches known as ‘blinkers’ may be explained as the result of an instability in transition layer magnetic flux tubes, which are represented by a set of isolated, high-aspect ratio vertical cylinders as the legs of coronal plasma loops. An essential prerequisite for the instability is that the heating, which is assumed to be only due to ohmic dissipation, closely balances the radiation losses. The instability occurs in the plasma pressure and could be triggered by a random shock wave; it rapidly increases the local pressure and results in a minor ‘explosion’. By dissipating energy away from the region, this reduces the local pressure and restores stability on a timescale of a few minutes, which is in agreement with observations of blinkers. The theory is an extension of Ashbourn and Woods’ previous treatment of the transition layer differential emission measure.