Gerhard Haerendel, Max Planck Institute for Extraterrestrial Physics

Topic: "Fascinating Plasma Structures - comet tails, auroral arcs, and solar prominences"  (Video)

Abstract: The lecture covers three themes from the past and present research of the lecturer. They have in common their relation to dynamic visible plasma structures. For all of them, a particular physical aspect has been selected for this presentation. Ambipolar momentum transfer dominates the interaction of the solar wind with a barium plasma cloud released from a German satellite 25 years ago. The term magnetic fractures is used to describe the process by which sheared magnetic flux tubes decouple from the line-tying ionosphere, whereby the liberated magnetic energy is being converted into kinetic energy of the auroral electrons. Downflows of cool plasma in quiescent solar prominences, as recently observed by the Solar Optical Telescope of the Japanese Hinode satellite, are interpreted as falling plasma droplets, i.e. plasmoids with detached magnetic field subject to drag forces caused by deformations of the ambient, mostly horizontal magnetic field during the downfall.