Coronal mass ejections and the solar wind: New results from LASCO Original Research Article

The LASCO and EIT experiments on SOHO have provided a revolutionary picture of coronal dynamics. In the past, the corona has largely been thought to be a region where the evolution of the coronal structures occurred on relatively large time scales, aside from the intermittent coronal mass ejection. The outflows in the polar coronal holes were largely considered to be time-independent. The picture now presented by the LASCO and EIT observations are of a highly dynamic corona. Continual small scale sporadic outflows are observed in quiet streamers and in the polar coronal holes. The LASCO images of CMEs shows that many appear to have circular structures that indicate that they consist of helical magnetic flux ropes. In addition, a new class of CMEs has been observed and are called ‘global’ CMEs since they appear to involve regions of the corona separated by as much as 180°.