Heidelberg 2022 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 12: Sun and Heliosphere
EP 12.11: Vortrag
Freitag, 25. März 2022, 13:50–14:00, EP-H1
Confined and Subsequent Full Flux Rope Eruption as a Model for Homolous Solar Events — Alshaimaa Hassanin1, •Bernhard Kliem2, Norbert Seehafer2, and Tibor Török3 — 1Department of Astronomy, Space Science & Meteorology, Faculty of Science, University of Cairo, Egypt — 2Institute of Physics and Astronomy, University of Potsdam, Germany — 3Predictive Science Inc., San Diego, CA 92121, USA
We present the first numerical model of a sequence of a confined and a full eruption (i.e., a coronal mass ejection, CME). The first eruption results from the helical kink instability of a sufficiently twisted magnetic flux rope; it remains confined because the flux rope does not reach the critical height for onset of the torus instability. A two-step reconnection process reforms a flux rope with subcritical twist near the position of the original flux rope. The full eruption develops as a result of converging motions imposed at the photospheric boundary, which drive flux cancellation. In this process, a part of the positive and negative sunspot flux converge toward the polarity inversion line, reconnect, and cancel each other. Flux of the same amount as the canceled flux transfers to the flux rope, increasing its free magnetic energy. With sustained flux cancellation and the associated progressive weakening of the magnetic tension of the overlying flux, we find that a flux reduction of ≈9% leads to the ejective eruption. These results demonstrate that homologous eruptions, eventually leading to a coronal mass ejection, can be driven by flux cancellation.