Active region evolution in association to coronal mass ejections.

Lucie M. Green

Abstract

Coronal mass ejections (CMEs) can be related to smaller scale activity in the lower corona, for example filament eruptions, flares and regions of dimming. Previous work has studied CMEs in relation to these single events rather than observing the long term changes in magnetic field configuration which be may necessary for the initiation of a CME. When trying to understand the launch process of the CME the evolution, as well as location, of energy build-up and release is important.

This study presents results on the evolution of active region magnetic fields in relation to CMEs. Multi instrument observations are used including the Extreme-Ultraviolet Imaging Telescope (EIT), Michelson Doppler Imager (MDI), the Large Angle Spectroscopic Coronagraph (LASCO) on SoHO, and the Soft X-Ray telescope (SXT) on Yohkoh. The CME association to the active region is made through the identification of signatures associated with the CME launch visible with EIT and LASCO white light images. Changes in the active region and their implications for the global magnetic field and the launch mechanism of CMEs arediscussed.
 
 

  Organization: Mullard Space Science Laboratory, UCL
     Telephone: 01483 204162
           Fax: 01483 278312
        e-mail: lmg@mssl.ucl.ac.uk
       Address: Holmbury House
   Holmbury St. Mary
   Dorking
   Surrey
   RH5 6NT