Journal Article

Application of Double Beltrami states to solar eruptions

D. Kagan and S. M. Mahajan

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 406, issue 2, pages 1140-1145
Published in print August 2010 | ISSN: 0035-8711
Published online July 2010 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2010.16741.x
Application of Double Beltrami states to solar eruptions

More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics

GO

Show Summary Details

Preview

We show that the general class of Double Beltrami (DB) states, which are the lowest energy equilibria of Hall magnetohydrodynamics, can have characteristics similar to those of active regions in the solar corona and is capable of undergoing a catastrophe that can cause a solar eruption, such as a flare or coronal mass ejection (CME). We then show that the qualitative evolution of the DB state is consistent with that of a solar eruption. Finally, we make two quantitative comparisons of DB states to CMEs, which are the simplest result of the catastrophe. First, we show that the DB expansion by a factor of 1–2 before the catastrophe is consistent with the increase in the height of the leading edges of Large-Angle Spectrometric Coronagraph (LASCO C1) CMEs in the quasi-equilibrium stage. Secondly, we use the assumption that DB states are randomly chosen from the allowed phase space of coronal structures to predict that the probability of a coronal structure erupting is 0.046. Identifying active regions with DB states and using observational constraints to estimate that the state is replaced every 60 min by emerging loops results in a CME rate of 11 d−1, which is in reasonable agreement with the actual rate of about 6 d−1 at solar maximum.

Keywords: Sun: corona; Sun: coronal mass ejections (CMEs); Sun: flares; Sun: surface magnetism

Journal Article.  4626 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.