Chromospheric Flares

Giovanelli, R. G., Chromospheric Flares, MNRAS, 108, 163 (1948) (ADS)

The cartoon

(click on the image for a larger version)

One of the founding cartoons of flare theory, and perhaps the earliest in this Archive. Giovanelli's ideas went on to inspire not only the MHD-based theoretical work (e.g., Dungey; Gold & Hoyle; Cowling; Sweet; Parker and many others) but also theoretical work based upon electrical discharge, ie plasma physics requiring kinetic descriptions. This cartoon shows magnetic field lines emanating from "spots", the circles lying in the photospheric plane, plus currents (dashed lines) linking neutral points and flowing in sheets. The Archivist find this a little hard to understand! Note though that one sees the geometrical paraphernalia of 3D reconnection: separators, separatrices, spines and fans, much as in cartoons done generations later (e.g., the Bratenahl-Baum cartoon of 1976, or the Fletcher cartoon of half a century later).

      Note that this cartoon was also published in Giovanelli's 1947 paper.

Date: 2006 July 02

Update: 2019 February 13