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R. Wolfson (Middlebury College)
Coronal mass ejections (CMEs) involve the expulsion of some 1016 g of solar material into interplanetary space, at hundreds of kilometers per second. In one common scenario, the energy that powers a CME is stored gradually in the solar corona until a triggering event, instability, or loss of equilibrium initiates the mass ejection. Energy is required to open the coronal magnetic field, to accelerate the ejected material, and to lift the ejecta against solar gravity. In this work, we develop a model corona that includes both field-aligned (force-free) and cross-field electric currents supporting a mass distribution like that of the coronal helmet streamers in which many CMEs originate. We show how magnetic shear, when coupled with an appropriate mass distribution, can result in the buildup of energy sufficient to power a CME. We explore a range of shear profiles, and show that the ability of the corona to store sufficient energy for a CME may depend on the details of the shear applied to its magnetic footpoints.
This work was supported by NASA grant NAG5-9733 to Middlebury College.
The author(s) of this abstract have provided an email address for comments about the abstract: wolfson@middlebury.edu