A Multi-Scale Cascade to Initiate Solar Flares
Solar Physics, cilt.301, sa.10, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 301 Sayı: 10
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s11207-026-02742-x
- Dergi Adı: Solar Physics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, INSPEC, Academic Search Ultimate (EBSCO), Technology Collection (ProQuest)
- Anahtar Kelimeler: Corona, Dynamics, Flares, Magnetic fields
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
We suggest that the preflare and impulsive phases of a solar flare may be described in terms of a two-stage scenario. Stage I for the preflare phase is the marginally stable and linearly unstable development of a global MHD instability (torus or kink) that causes a magnetic flux rope containing a prominence to begin erupting slowly from equilibrium. It forms a current sheet with weak magnetic reconnection that produces weak EUV and X-ray brightenings and bidirectional outflows. Stage II for the impulsive phase of the flare consists of a transition from linear to nonlinear instability in which there is a multi-scale cascade to produce many small-scale current sheets with fast impulsive bursty reconnection, at which fast particle acceleration is likely to occur. There are two distinct types of flare to which this scenario applies. Type A is a new one suggested by Solar Orbiter observations (Chitta et al. 2026). In this case, Stage I involves kink instability, with weak reconnection at a current sheet within the flux rope. During the nonlinear development of Stage II, the jets expelled by the current sheet spawn a myriad of new current sheets throughout the flux rope. Type B is the usual model in which a torus instability drives weak reconnection at a current sheet below a rising flux rope or vice versa (Stage I), followed by a transition to fast impulsive bursty reconnection in the current sheet (Stage II). If both types occur simultaneously, with reconnection both within and under the flux rope, then four flare ribbons are produced.