3D Magnetic Field Configuration and Evolution of Coronal Mass Ejections

H. CREMADES; V. BOTHMER; D. TRIPATHI

Nice, France

Congreso; EGS - AGU - EUG Joint Assembly; 2003

EGU

Coronal Mass Ejections (CMEs) are the most energetic transient phenomena in the solar atmosphere. The origins of CMEs, their 3D structure and internal magnetic field configuration, as well as their evolution into interplanetary space are not well understood. Thanks to the high resolution telescopes of the SOHO Mission, for the first time magnetic fine structures can be resolved within CMEs observed close to the Sun. A set of CME events has been identified from a detailed investigation of LASCO (Large Angle Spectroscopic Coronagraph) observations taken since launch in 1995. This data set comprises those cases exhibiting white-light fine structures, from which their magnetic field configuration could be deduced. Since the observed white-light features are the result of an inherent line-of-sight integration projected on the plane of the sky, inferring the three-dimensional topology of CMEs is a challenging and complicated task. In order to reveal the actual 3D profile of a CME, an approach based on the characterization of their respective source region magnetic field configuration is addressed. The study indicates that many CMEs are comprised either of arcades of magnetic field lines or magnetic flux tubes which are trailed by prominence material. The analysis of additional coronal and magnetic field observations (EIT, MDI) shows that these magnetic structures seem to arise from already existing loop systems of much smaller scale that originate in bipolar field regions