Expansion of coronal mass ejections from the low to the outer corona

H. CREMADES; L. A. MERENDA; F. A. IGLESIAS; I. CABELLO; F.M. LOPEZ; L. A. BALMACEDA

CABA

Conferencia; XI COLAGE; 2018

ALAGE

Coronal mass ejections (CMEs) are key players in driving space weather and modifying the heliosphere?s conditions. Although great discoveries have been madesince their first detections more than 40 years ago, several pieces of the full puzzle are missing, being one of them how CMEs are structured and how this structure evolves fromthe low corona into the heliosphere. Exceptional ongoing solar missions provide a unique opportunity to shed light into this aspect, which would ultimately benefit not only spaceweather predictions but also the understanding of the underlying physics. The stereoscopic-view images provided by the STEREO/SECCHI suite in combination with images fromEarth?s perspective recorded by SDO/AIA and SOHO/LASCO allow the analysis of CME events in detail from their origins in the low corona. We selected four CMEs observed bythese instruments according to specific time spans and birth locations, with a preference toward spacecraft quadrature situations. These events are carefully analyzed from theirbirth low in the corona by means of simultaneous observations of STEREO/EUVI and SDO/AIA and followed into the fields of view of the STEREO and SOHO coronagraphs. Inparticular, the attributes of self-similarity and expansion rate are examined.