Post-Eruption Arcades and 3-D Magnetic Reconnection (Invited)
Klimchuk, James A., Post-Eruption Arcades and 3-D Magnetic Reconnection (Invited), 111, 319-330 (1996) (ADS)
(click on the image for a larger version)
The little asterisks are meant to be X-points (or "islands of
reconnection") to use the poetic touch; perhaps this term was inspired by
Coleridge [1].
This was not a prediction of the SADs phenomenon, which was not
discovered until 1999;
see the McKenzie for that.
It is also a bit misleading to refer to "post-eruption arcades", given that we
often see the two-ribbon arcade flare paraphernalia in the absence of
an eruption and can only conclude that the eruption itself,
though important in its own right and very interesting indeed,
is not a fundamental thing.
The Archivist believes that this cartoon points us towards some seriously
interesting problems.
The SAD downflows - now observed much better with AIA than SXT
ever did - consist of voids included in a still slower downwards flow,
and moving at sub-Alfvénic
speeds.
See the TRACE movie for SOL2002-04-20 or many another example, for reference.
These flows fit into the proper CSHKP geometry, but not
well physically in terms of its suggestion of
super-Alvénic speeds.
Furthermore the geometry is complicated, as hinted at by this cartoon.
How do the separatrices evolve?
What flux is transferring to where, and why are there discrete points, rather
than a turbulent continuum?
The little asterisks are meant to be X-points (or "islands of reconnection") to use the poetic touch; perhaps this term was inspired by Coleridge [1]. This was not a prediction of the SADs phenomenon, which was not discovered until 1999; see the McKenzie for that. It is also a bit misleading to refer to "post-eruption arcades", given that we often see the two-ribbon arcade flare paraphernalia in the absence of an eruption and can only conclude that the eruption itself, though important in its own right and very interesting indeed, is not a fundamental thing.
The Archivist believes that this cartoon points us towards some seriously interesting problems. The SAD downflows - now observed much better with AIA than SXT ever did - consist of voids included in a still slower downwards flow, and moving at sub-Alfvénic speeds. See the TRACE movie for SOL2002-04-20 or many another example, for reference. These flows fit into the proper CSHKP geometry, but not well physically in terms of its suggestion of super-Alvénic speeds. Furthermore the geometry is complicated, as hinted at by this cartoon. How do the separatrices evolve? What flux is transferring to where, and why are there discrete points, rather than a turbulent continuum?
[1] Coleridge.