Coronal mass ejections (CMEs) are dynamic events that typically involve the expulsion of 10(15) to 10(16) grams of coronal and chromospheric plasma into interplanetary space. The relationship between mass ejections and other forms of solar activity, especially those evident on the solar disk, remains unclear. In an attempt to accurately determine CME onset times and origins, we have combined observations from the Solar Heliospheric Observatory (SOHO) Large Angle Spectroscopic Coronagraphs (LASCO), the SOHO Extreme Ultraviolet Imaging, the Mauna Loa Observatory (MLO) white light and chromospheric instruments and the Yohkoh Soft X-ray Telescope. Mass ejections believed to have occurred both at or near the limb of the sun and on the solar disk have been employed in the comparison. When available, the MLO and LASCO white light observations have been combined to determine material trajectories, and hence accurate CME onset times. The evolution of the magnetic fields and associated plasma structures prior to, during and after mass ejections have been examined by comparing He-I and Hα chromospheric disk signatures with EUV and X-ray observations.
AAS/Solar Physics Division Meeting #28
- Pub Date:
- May 1997