How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?

The geoeffective magnetic cloud (MC) of 20 November 2003 was associated with the 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had a positive sign, as did its solar source, active region (AR) NOAA 10501. In t...

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Guardado en:
Detalles Bibliográficos
Publicado: 2009
Materias:
Active regions; magnetic fields
Coronal mass ejections; interplanetary
Flares; dynamics, relation to magnetic field
Helicity; magnetic
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v261_n1_p127_Chandra
http://hdl.handle.net/20.500.12110/paper_00380938_v261_n1_p127_Chandra
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00380938_v261_n1_p127_Chandra
record_format dspace
spelling paper:paper_00380938_v261_n1_p127_Chandra2023-06-08T15:02:43Z How can a negative magnetic helicity active region generate a positive helicity magnetic cloud? Active regions; magnetic fields Coronal mass ejections; interplanetary Flares; dynamics, relation to magnetic field Helicity; magnetic The geoeffective magnetic cloud (MC) of 20 November 2003 was associated with the 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had a positive sign, as did its solar source, active region (AR) NOAA 10501. In this article we show that the large-scale magnetic field of AR 10501 has a negative helicity sign. Since coronal mass ejections (CMEs) are one of the means by which the Sun ejects magnetic helicity excess into interplanetary space, the signs of magnetic helicity in the AR and MC must agree. Therefore, this finding contradicts what is expected from magnetic helicity conservation. However, using, for the first time, correct helicity density maps to determine the spatial distribution of magnetic helicity injections, we show the existence of a localized flux of positive helicity in the southern part of AR 10501. We conclude that positive helicity was ejected from this portion of the AR leading to the observed positive helicity MC. © Springer Science+Business Media B.V. 2009. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v261_n1_p127_Chandra http://hdl.handle.net/20.500.12110/paper_00380938_v261_n1_p127_Chandra
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Active regions; magnetic fields
Coronal mass ejections; interplanetary
Flares; dynamics, relation to magnetic field
Helicity; magnetic
spellingShingle Active regions; magnetic fields
Coronal mass ejections; interplanetary
Flares; dynamics, relation to magnetic field
Helicity; magnetic
How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
topic_facet Active regions; magnetic fields
Coronal mass ejections; interplanetary
Flares; dynamics, relation to magnetic field
Helicity; magnetic
description The geoeffective magnetic cloud (MC) of 20 November 2003 was associated with the 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had a positive sign, as did its solar source, active region (AR) NOAA 10501. In this article we show that the large-scale magnetic field of AR 10501 has a negative helicity sign. Since coronal mass ejections (CMEs) are one of the means by which the Sun ejects magnetic helicity excess into interplanetary space, the signs of magnetic helicity in the AR and MC must agree. Therefore, this finding contradicts what is expected from magnetic helicity conservation. However, using, for the first time, correct helicity density maps to determine the spatial distribution of magnetic helicity injections, we show the existence of a localized flux of positive helicity in the southern part of AR 10501. We conclude that positive helicity was ejected from this portion of the AR leading to the observed positive helicity MC. © Springer Science+Business Media B.V. 2009.
title How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
title_short How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
title_full How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
title_fullStr How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
title_full_unstemmed How can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
title_sort how can a negative magnetic helicity active region generate a positive helicity magnetic cloud?
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v261_n1_p127_Chandra
http://hdl.handle.net/20.500.12110/paper_00380938_v261_n1_p127_Chandra
_version_ 1768543551400968192

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