PARTICLE-ACCELERATION AND DYNAMICAL CHANGES IN THE CORONA

Electrons are accelerated to suprathermal energies in the corona both during and outside flares. In the absence of flares electrons of some keV to some tens of keV are detected through noise storm emission at decimetric and metric wavelengths. This contribution presents a study of noise storms with the Nancay Radioheliograph, conducted for probing the link of the emission with the reconfiguration of the coronal magnetic field. Comparison with whole-Sun soft X-ray fluxes (GOES) reveals for the first time a systematic association of noise storm emission with energy release in the low corona. The observations suggest that noise storms arise when the coronal magnetic field adjusts to new boundary conditions imposed by the modification of the underlying active region.