Using the Evolution of Coronal Dimming Regions to Probe the Global Magnetic Field Topology

Attrill, G., M. S. Nakwacki, L. K. Harra, L. van Driel-Gesztelyi, C. H. Mandrini, S. Dasso, and J. Wang, Using the Evolution of Coronal Dimming Regions to Probe the Global Magnetic Field Topology, Sol. Phys., 238, 117-139 (2006) (ADS)

The cartoon

(click on the image for a larger version)

The event SOL1997-05-12, comprising flare, CME, and EIT waves - had a major impact because it was so well observed by Yohkoh, SOHO (and TRACE?) in space, and by ground-based magnetographs. The corona was in a fairly simple solar-minimum state prior to the major rise of the new sunspot cycle. A similar event (SOL1994-11-13) produced an "aurora solaris," so-named by Sam Freeland, where one could see large-scale perturbations of the X-ray corona including the polar crown region. This cartoon bravely tries to link such a global development to the flare proper, specifically to its twin dimming regions (transient coronal holes). Magnetic reconnection, yes, but driven reconnection. Note that the cartoon is labeled "OCH" despite the fact that the very international author list does not seem to include any Scots. Note yet another possible misuse of the word "topology."

Date: 2007 January 20

Update: 2019 January 18