Solar Physics

, Volume 193, Issue 1, pp 227–245

Magnetic Activity Associated With Radio Noise Storms

  • R.D. Bentley
  • K.-L. Klein
  • L. van Driel-Gesztelyi
  • P. Démoulin
  • G. Trottet
  • P. Tassetto
  • G. Marty
Article

DOI: 10.1023/A:1005218007132

Cite this article as:
Bentley, R., Klein, K., van Driel-Gesztelyi, L. et al. Solar Physics (2000) 193: 227. doi:10.1023/A:1005218007132

Abstract

As it crossed the solar disk in May and June 1998, AR 8227 was tracked by TRACE, Yohkoh, SOHO, and many ground-based observatories. We have studied how the evolution of the magnetic field resulted in changes in activity in the corona. In particular, we examine how the evolving field may have led to the acceleration of electrons which emit noise storms observed by the Nançay Radio Heliograph between 30 May and 1 June 1998, in the absence of any flare. The magnetic changes were related to moving magnetic features (MMFs) in the vicinity of the leading spot and are related to the decay of this spot. Within the limits of the instrumental capabilities, the location in time and space of the radio emissions followed the changes observed in the photospheric magnetograms. We have extrapolated the photospheric magnetic field with a linear force-free approximation and find that the active region magnetic field was very close to being potential. These computations show a complex magnetic topology associated to the MMFs. The observed photospheric evolution is expected to drive magnetic reconnection in such complex magnetic topology. We therefore propose that the MMFs are at the origin of the observed metric noise-storms.

Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • R.D. Bentley
    • 1
  • K.-L. Klein
    • 2
  • L. van Driel-Gesztelyi
    • 2
  • P. Démoulin
    • 2
  • G. Trottet
    • 2
  • P. Tassetto
    • 2
  • G. Marty
    • 2
  1. 1.Mullard Space Science LaboratoryUniversity College LondonSurreyU.K.
  2. 2.Section de Meudon, DASOPObservatoire de ParisPrincipal CedexFrance