A ?magnetospheric? scenario of the solar flare in a quadrupole magnetic configuration

Abstract

An attempt is made to impart a constructive character to the concept of the solar flaremagnetospheric substorm analogy. An idealized scheme for a two-ribbon solar flare in the originally closed magnetosphere of the active region is discussed. The basis is formed by a terrestrial substorm scenario with two active phases (Mishin et al., 1992). While a quadrupole magnetic configuration turns out to be a ‘solar’ analog of the Earth's magnetosphere. A physical mechanism that sustains the preflare ‘storage’ phase, is provided by an instability like a ‘stretching instability’ of the closed geomagnetotail. The ‘storage’ process is attributed to the emergence into the corona of closed magnetic flux lines in adjacent (to the location of the would-be flare) regions. The flare flash-phase is determined by the change-over of the ‘stretching instability’ to a disruption instability of a nonstationary (not neutral) current sheet inside the ‘storage’ zone. The final recovery phase corresponds to the wellknown Pneuman-Kopp model.