SPRG Seminars
February 24, 2009:
" Evolution of coronal mass ejections from the Sun to interplanetary space: A new view with STEREO "
Ying Liu,
University of California, Berkeley, Space Sciences Laboratory
Coronal mass ejections (CMEs) are the most spectacular eruptions in the solar atmosphere and have been recognized as primary drivers of interplanetary disturbances. This talk will focus on the recent progress in understanding the evolution and propagation of CMEs thanks to STEREO observations, specifically (1) the relationship between coronal metric type II bursts and CME-driven shocks, a long standing source of controversy in solar and space physics; (2) tracking and reconstruction of CMEs using coordinated imaging and in situ observations; and (3) regulation of the global field configuration of the corona and heliosphere by CMEs (if I have time for this topic). The unprecedented high-cadence imaging observations from STEREO can observe CMEs in their early acceleration phase and thus clarify unambiguously the origin of metric type II bursts. CMEs can be imaged continuously out to distances beyond 1 AU from vantage points off the Sun-Earth line; geometric triangulation of the white-light observations, combined with in situ measurements, can determine the global morphology, propagation direction and orientation of CMEs. Comparison between modeled and observed streamer belts, as viewed from different vantage points, allows us to see the changes in the global field configuration of the corona and heliosphere during CMEs.