skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections

Abstract

In typical observations of coronal mass ejections (CMEs), a magnetic structure of a helmet-shaped closed configuration bulges out and eventually opens up. However, a spontaneous transition between these field configurations has been regarded to be energetically impossible in force-free fields according to the Aly-Sturrock theorem. The theorem states that the maximum energy state of force-free fields with a given boundary normal field distribution is the open field. The theorem implicitly assumes the existence of the maximum energy state, which may not be taken for granted. In this study, we have constructed force-free fields containing tangential discontinuities in multiple flux systems. These force-free fields can be generated from a potential field by footpoint motions that do not conserve the boundary normal field distribution. Some of these force-free fields are found to have more magnetic energy than the corresponding open fields. The constructed force-free configurations are compared with observational features of CME-bearing active regions. Possible mechanisms of CMEs are also discussed.

Authors:
;
Publication Date:
Research Org.:
Princeton Plasma Physics Lab., NJ (US)
Sponsoring Org.:
USDOE Office of Science (US)
OSTI Identifier:
798171
Report Number(s):
PPPL-3692.pdf
TRN: US0202143
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 9 May 2002
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CLOSED CONFIGURATIONS; DISTRIBUTION; FORCE-FREE MAGNETIC FIELDS

Citation Formats

G.S. Choe, and C.Z. Cheng. Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections. United States: N. p., 2002. Web. doi:10.2172/798171.
G.S. Choe, & C.Z. Cheng. Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections. United States. doi:10.2172/798171.
G.S. Choe, and C.Z. Cheng. Thu . "Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections". United States. doi:10.2172/798171. https://www.osti.gov/servlets/purl/798171.
@article{osti_798171,
title = {Energy of Force-Free Magnetic Fields in Relation to Coronal Mass Ejections},
author = {G.S. Choe and C.Z. Cheng},
abstractNote = {In typical observations of coronal mass ejections (CMEs), a magnetic structure of a helmet-shaped closed configuration bulges out and eventually opens up. However, a spontaneous transition between these field configurations has been regarded to be energetically impossible in force-free fields according to the Aly-Sturrock theorem. The theorem states that the maximum energy state of force-free fields with a given boundary normal field distribution is the open field. The theorem implicitly assumes the existence of the maximum energy state, which may not be taken for granted. In this study, we have constructed force-free fields containing tangential discontinuities in multiple flux systems. These force-free fields can be generated from a potential field by footpoint motions that do not conserve the boundary normal field distribution. Some of these force-free fields are found to have more magnetic energy than the corresponding open fields. The constructed force-free configurations are compared with observational features of CME-bearing active regions. Possible mechanisms of CMEs are also discussed.},
doi = {10.2172/798171},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2002},
month = {5}
}