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Processes and mechanisms governing the initiation and propagation of CMEs


Vršnak, Bojan
Processes and mechanisms governing the initiation and propagation of CMEs // Annales Geophysicae - Atmospheres Hydrospheres and Space Sciences, 26 (2008), 10; 3089-3101 (međunarodna recenzija, članak, znanstveni)


Naslov
Processes and mechanisms governing the initiation and propagation of CMEs

Autori
Vršnak, Bojan

Izvornik
Annales Geophysicae - Atmospheres Hydrospheres and Space Sciences (0992-7689) 26 (2008), 10; 3089-3101

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Solar physics; astrophysics; and astrnomy (Flares and mass ejection)

Sažetak
The most important observational characteristics of coronal mass ejections (CMEs) are summarized, emphasizing those aspects which are relevant for testing physical concepts employed to explain the CME take-off and propagation. In particular, the kinematics, scalings, and the CMEflare relationship are stressed. Special attention is paid to 3- dimensional (3-D) topology of the magnetic field structures, particularly to aspects related to the concept of semi-toroidal flux-rope anchored at both ends in the dense photosphere and embedded in the coronal magnetic arcade. Observations are compared with physical principles and concepts employed in explaining the CME phenomenon, and implications are discussed. A simple flux-rope model is used to explain various stages of the eruption. The model is able to reproduce all basic observational requirements: stable equilibrium and possible oscillations around equilibrium, metastable state and possible destabilization by an external disturbance, pre-eruptive gradual-rise until loss of equilibrium, possibility of fallback events and failed eruptions, relationship between impulsiveness of the CME acceleration and the source-region size, etc. However, it is shown that the purely ideal MHD process cannot account for highest observed accelerations which can attain values up to 10 km s− 2. Such accelerations can be achieved if the process of reconnection beneath the erupting flux-rope is included into the model. Essentially, the role of reconnection is in changing the magnetic flux associated with the flux-rope current and supplying “ fresh” poloidal magnetic flux to the rope. These effects help sustain the electric current flowing along the flux-rope, and consequently, reinforce and prolong the CME acceleration. The model straightforwardly explains the observed synchronization of the flare impulsive phase and the CME main-acceleration stage, as well as the correlations between various CME and flare parameters.

Izvorni jezik
Engleski

Znanstvena područja
Fizika



POVEZANOST RADA


Projekt / tema
007-0000000-1362 - Eruptivni procesi u Sunčevoj atmosferi (Bojan Vršnak, )

Ustanove
Geodetski fakultet, Zagreb

Profili:

Avatar Url Bojan Vršnak (autor)

Citiraj ovu publikaciju

Vršnak, Bojan
Processes and mechanisms governing the initiation and propagation of CMEs // Annales Geophysicae - Atmospheres Hydrospheres and Space Sciences, 26 (2008), 10; 3089-3101 (međunarodna recenzija, članak, znanstveni)
Vršnak, B. (2008) Processes and mechanisms governing the initiation and propagation of CMEs. Annales Geophysicae - Atmospheres Hydrospheres and Space Sciences, 26 (10), 3089-3101.
@article{article, author = {Vr\v{s}nak, B.}, year = {2008}, pages = {3089-3101}, keywords = {Solar physics, astrophysics, and astrnomy (Flares and mass ejection)}, journal = {Annales Geophysicae - Atmospheres Hydrospheres and Space Sciences}, volume = {26}, number = {10}, issn = {0992-7689}, title = {Processes and mechanisms governing the initiation and propagation of CMEs}, keyword = {Solar physics, astrophysics, and astrnomy (Flares and mass ejection)} }

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus


Uključenost u ostale bibliografske baze podataka:


  • NASA-ADS