What is CSHKP?

The CSHKP acronym refers to four key theoretical papers that appeared over the time frame 1964-1976: Carmichael, Sturrock, Hirayama, and Kopp & Pneuman. It might be easy to imagine that nothing new has happened since then, except for minor tweaks, judging from the Archive contents!

The basic idea for the cartoon must have originated in Hα observations of the "loop prominence system". This in turn could readily be identified in the 1960s with the "sporadic coronal condensation" observable in the Ca XV yellow coronal line, and associated with hot overdense plasma in the corona, feeding the flare ribbons and leading to "coronal rain". On top of this, the strong association of great flares with "solar cosmic rays" was well known - these were the "proton flares." This was well captured in the series of papers by Jefferies, Orrall, and Zirker as exemplified in their 1965 cartoon. Note however that this cartoon envisioned a fixed magnetic structure in which "corpuscles" did their thing.

The CSHKP cartoon represented the inclusion of field restructuring into this picture. This particular cartoon introduced no new ideas, but was among the first in the Archive to make use of color! CMEs had become known in the 1970s, but the problematic association of geomagnetic disturbances with sunspot groups was common knowledge since the days of Carrington [1] and Balfour Stewart [2]. These hints made the need for some process of global extent necessary, and CSHKP captured this with the opening of the coronal field, a current-sheet development, and magnetic reconnection.

But wait! This cartoon does not grapple with causation! It is intuitively and computationally true that the expansion of the field, so well-reflected in CME action, actually requires additional energy input. This inflation could be as mysterious as its cosmological counterpart, perhaps; people dismiss its importance by claiming that a CME is "magnetically driven" and then not complaining further. The current within the current sheet thus only reflects excess energy that has been put there by the initial phases of the disturbance (the impulsive phase). Where is that current coming from, where is it going to, and what might the observational consequences be?? None of the CSHKP-inspired cartoons in the Archive deal very well with that basic question.

[1] Carrington
[2] Balfour_Stewart