NAM 2021 Session: Instabilities, nonlinearities and heating in the solar corona

April 26, 2021, from Natasha Jeffrey

We invite abstracts for a session at the National Astronomy Meeting 2021, entitled ‘Instabilities, nonlinearities and heating in the solar corona’.

The current generation of advanced solar observing facilities is beginning to reveal the nature of the corona in unprecedented detail. Whilst it is becoming increasingly clear that dynamic and complex behaviour is pervasive throughout the Sun’s atmosphere, many of the observed physical processes remain poorly understood. This session will explore magnetohydrodynamic (MHD) instabilities, wave-induced turbulence and the nature of the energy release which sustains the multi-million degree coronal temperatures.

Mechanisms proposed to explain coronal heating can be grouped according to the temporal behaviour of the underlying energy source. On one hand, long time scale flows will slowly build magnetic stress which can be released through reconnection events and on the other, short time scale flows will induce MHD waves which can dissipate in the corona. The relative importance of these two categories remains unclear and may well vary throughout the coronal volume. In either case, for significant energy release to occur, small length scales must be generated in either the magnetic or velocity fields (or both). A popular mechanism by which these small scales may arise is the formation of an energy cascade during the development of MHD turbulence. This may form as a result of the nonlinear interaction of counter-propagating wave modes, the disruption of unidirectionally propagating kink modes or due to dynamic and thermal instabilities such as the Kelvin-Helmholtz and Rayleigh-Taylor-type instabilities. All of these nonlinear phenomena must be explored in detail in order to fully understand the complex nature of the solar corona.

Abstract submission:
Deadline for abstracts: 30 April 2021

Kind regards,

Norbert Magyar, Thomas Howson, Patrick Antolin, Andrew Hillier, Jack Reid