The Evolution of Dark Canopies Around Active Regions

Wang, Y.-M., E. Robbrecht, and K. Muglach, The Evolution of Dark Canopies Around Active Regions, ApJ, 733, 20 (2011) (ADS)

The cartoon

(click on the image for a larger version)

Somewhat far field from flare physics, this cartoon actually aims to explain an aspect of one of the most boring solar features: the Hα fibril pattern. But this is both beautiful and also relevant to flare physics in the sense that large-scale coronal fields in the vicinity of active regions, the "dark canopy" of an active region, of course matter in terms of magnetic stress and the global energetics of the field. This well-drawn cartoon describes three ways in which a fibril (the heavy dashed line) may connect with emerging bipolar flux on small scales. The implication is that reconnections at low altitude are required, just as one sees in jet formation (and hence, associated microflare activity perhaps.

Date: 2020 July 22