Emergence and Drastic Breakdown of a Twisted Flux Rope to Trigger Strong Solar Flares in NOAA Active Region 9026

Kurokawa, Hiroki, Tongjiang Wang, and Takako T. Ishii, Emergence and Drastic Breakdown of a Twisted Flux Rope to Trigger Strong Solar Flares in NOAA Active Region 9026, ApJ, 572, 598-608 (2002) (ADS)

The cartoon

(click on the image for a larger version)

A cartoon describing a physical process, rather than some mechanism for flare or CME behavior. This cartoon appeals to the coherent emergence of a twisted flux tube from below the photosphere; this would advect magnetic energy into the corona, where it would wait and accumlate for an unknown time interval before a restructuring releases the energy as a flare. Writhe and twist helicity are exchanged, and there is no real appeal to large-scale magnetic reconnection as such. An interesting aspect of this kind of picture is that it can explain "homology" as long as one allows for the possibility of larger-scale coherence beneath the photosphere. Unfortunately, nobody really knows much in detail about the behavior of the magnetic field below the photosphere - see the equation J = General in the celebrated Piddington cartoon. The region just below the photosphere, where the thin flux-tube approximation is invalid, may be the most ill-understood.

      An earlier suggestion of the mapping of subphotospheric vertical structure into photospheric image morphology appears in the Tanaka cartoon.

Date: 2006 April 13

Update: 2019 February 15