Expansion of coronal mass ejections from the low corona and beyond

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

Buenos Aires

Congreso; XI COLAGE; 2018

Coronal mass ejections (CMEs) are key players in driving space weather and modifying heliosphere?s conditions. Although great discoveries have been made since 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 from the low corona into the heliosphere. The exceptional ongoing solar missions provide a unique opportunity to shed light into this aspect, which would ultimately benefit not only space weather predictions but also the understanding of the underlying physics. The stereoscopic-view images provided by the STEREO/SECCHI suite in combination with images from Earth?s perspective recorded by SDO/AIA and SOHO/LASCO allow the analysis of CME events in detail from their origins in the low corona. A small set of CMEs observed by these instruments is selected according to specific time spans and birth locations, with a preference toward spacecraft quadrature situations. These events are carefully analyzed from their birth 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. In particular, the attributes of self-similarity, expansion rate and ratios, as well as the presence and direction of flux ropes are examined.