Observed signatures of magnetic energy conversion in solar flares and microflares

MANDRINI, C.H.; MACHADO, M.E.; HERNÁNDEZ, A.M.; ROVIRA, M.G.

ADVANCES IN SPACE RESEARCH

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 1990 vol. 10 p. 115 - 119

0273-1177

We follow up on our earlier studies of the characteristics of energy release in solar flares, extending it to weak flare-like transient brightenings which are called microflares. We find that all events share similar properties in spite of their large differences in X-ray brightness, including the fact that their trigger seems to be due to the interaction of impacted bipolar regions which leads to the release of their internally stored energy. The overall topology of the energy release region is preserved over a period in which an active region produced numerous events, except at the site of a two ribbon flare, which probably led to a permanent disruption of the magnetic configuration. Our results suggest that transient microflares can be responsible for a large fraction of the coronal heating in active regions, and we propose a picture in which reconnection may act as a catalyst for the release of stored magnetic energy.