Grad Talk- The Role of Plasma, Heating, and Energetics of Solar Coronal Mass Ejections

Abstract: Coronal Mass Ejections (CMEs) are bodily expulsions of hot plasma and magnetic fields from the solar corona. Such ejections, which are often directed towards the Earth cause geomagnetic storms, which substantially affect technologies we use on a routine basis. This has prompted extensive investigations of the manner in which CMEs are initiated in the solar corona and the manner in which they propagate through the heliosphere. However, there has not been as much attention devoted to the energy expended in expanding and heating the CME as it propagates. These are crucial issues, the answers to which can substantially impact our understanding of CME dynamics. 
 Were the CMEs to expand adiabatically from near the sun to the earth, then their temperature would be no more than a few degrees of kelvin. But the observed temperatures of CME plasma intercepted near the Earth are around a hundred thousand kelvins. Furthermore, our understanding of laboratory tokamak plasmas suggests that expanding magnetic flux ropes (such as CMEs) should contract in cross-section, whereas CMEs are observed to expand. These suggest that our understanding of CME driving and thermodynamics is far from complete.