Y. Uchida and K. Shibata, "A magnetodynamic mechanism for the heating
of emerging magnetic flux tubes and loop flares," Solar Phys. 116, 291 (1988).
Click on the image above for a larger version.
This cartoon offered a neat way to get magnetic energy release in the corona without magnetic reconnection. A pair of twist waves (large and powerful Alfven waves in the Alfven mode) erupt from the photosphere and collide at the top of the flux tube they are perturbing. This collision results in a cancellation of the twist and (voila! -or, sasuga!) energy. While it seemed to the Archivist that this model had a fatal weakness, it still served to make the important pedagogical point that reconnection is not the only theoretical option for magnetic energy release in the corona. The weakness is the time scale involved in the upward propagation of the twist wave packet. Another niggling consideration is the need for two simultaneous wave packets, something that can't generally be expected to happen. The paper explains this in terms of the stress imposed at the actual surface just prior to eruption; that sounds quite wrong, though.
Maybe the improbability of this model is just the point, though; flares don't occur all the time, so maybe just when the perfect wave arrives. Most flares do appear not to involve eruption or geometrical change (hence "simple loop flares"), so these would be the ones at which this model would be aimed.
The cartoon of Fletcher & Hudson sort of continues this picture. Note also the artistic resemblance to a Sturrock et al cartoon.
Dec. 29, 2006
Jan. 19, 2007
Feb. 2, 2007
Sept. 21, 2008
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