The physical mechanisms that initiate and drive solar eruptions
Guillaume Aulanier Submitted: 2013-09-27 02:25
Solar eruptions are due to a sudden destabilization of force-free coronal
magnetic fields. But the detailed mechanisms which can bring the corona
towards an eruptive stage, then trigger and drive the eruption, and
finally make it explosive, are not fully understood. A large variety of
storage-and-release models have been developed and opposed to each other since
40 years. For example, photospheric flux emergence vs. flux cancellation,
localized coronal reconnection vs. large-scale ideal instabilities and loss of
equilibria, tether-cutting vs. breakout reconnection, and so on. The competition
between all these approaches has
led to a tremendous drive in developing and testing all these concepts, by
coupling state-of-the-art models and observations. Thanks to these developments,
it now becomes possible to compare all these models with one another, and to
revisit their interpretation in light of their common and their different behaviors.
This approach leads me to argue that no more than two distinct physical mechanisms
can actually initiate and drive prominence eruptions: the magnetic breakout and
the torus instability. In this view, all other processes (including flux
emergence, flux cancellation, flare reconnection and long-range couplings) should
be considered as various ways that lead to, or than strengthen, one of the
aforementioned driving mechanisms.
Authors: Aulanier G.
Publication Status: Proceedings of the IAU S300, in press
Last Modified: 2013-09-30 10:00