Magnetic Flux and Helicity of Magnetic Clouds

Magnetic clouds (MCs) are formed by flux ropes (FRs) launched from the Sun as part of coronal mass ejections (CMEs). They carry away a large amount of magnetic flux and helicity. The main aim of this study is to quantify these amounts from in situ measurements of MCs at 1 AU. The fit of these data b...

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Autor principal: Dasso, Sergio Ricardo
Publicado: 2016
Materias:
Coronal mass ejections
Helicity, magnetic
Magnetic fields, interplanetary
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v291_n2_p531_Demoulin
http://hdl.handle.net/20.500.12110/paper_00380938_v291_n2_p531_Demoulin
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00380938_v291_n2_p531_Demoulin
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spelling paper:paper_00380938_v291_n2_p531_Demoulin2023-06-08T15:02:54Z Magnetic Flux and Helicity of Magnetic Clouds Dasso, Sergio Ricardo Coronal mass ejections Helicity, magnetic Magnetic fields, interplanetary Magnetic clouds (MCs) are formed by flux ropes (FRs) launched from the Sun as part of coronal mass ejections (CMEs). They carry away a large amount of magnetic flux and helicity. The main aim of this study is to quantify these amounts from in situ measurements of MCs at 1 AU. The fit of these data by a local FR model provides the axial magnetic field strength, the radius, the magnetic flux, and the helicity per unit length along the FR axis. We show that these quantities are statistically independent of the position along the FR axis. We then derive the generic shape and length of the FR axis from two sets of MCs. These results improve the estimation of magnetic helicity. Next, we evaluate the total magnetic flux and helicity that cross the sphere of radius of 1 AU, centred at the Sun, per year and during a solar cycle. We also include in the study two sets of small FRs that do not have all the typical characteristics of MCs. While small FRs are at least ten times more numerous than MCs, the magnetic flux and helicity are dominated by the contribution from the larger MCs. In one year they carry away the magnetic flux of about 25 large active regions and the magnetic helicity of 200 of them. MCs carry away an amount of unsigned magnetic helicity similar to the amount estimated for the solar dynamo and that measured in emerging active regions. © 2015, Springer Science+Business Media Dordrecht. Fil:Dasso, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v291_n2_p531_Demoulin http://hdl.handle.net/20.500.12110/paper_00380938_v291_n2_p531_Demoulin
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Coronal mass ejections
Helicity, magnetic
Magnetic fields, interplanetary
spellingShingle Coronal mass ejections
Helicity, magnetic
Magnetic fields, interplanetary
Dasso, Sergio Ricardo
Magnetic Flux and Helicity of Magnetic Clouds
topic_facet Coronal mass ejections
Helicity, magnetic
Magnetic fields, interplanetary
description Magnetic clouds (MCs) are formed by flux ropes (FRs) launched from the Sun as part of coronal mass ejections (CMEs). They carry away a large amount of magnetic flux and helicity. The main aim of this study is to quantify these amounts from in situ measurements of MCs at 1 AU. The fit of these data by a local FR model provides the axial magnetic field strength, the radius, the magnetic flux, and the helicity per unit length along the FR axis. We show that these quantities are statistically independent of the position along the FR axis. We then derive the generic shape and length of the FR axis from two sets of MCs. These results improve the estimation of magnetic helicity. Next, we evaluate the total magnetic flux and helicity that cross the sphere of radius of 1 AU, centred at the Sun, per year and during a solar cycle. We also include in the study two sets of small FRs that do not have all the typical characteristics of MCs. While small FRs are at least ten times more numerous than MCs, the magnetic flux and helicity are dominated by the contribution from the larger MCs. In one year they carry away the magnetic flux of about 25 large active regions and the magnetic helicity of 200 of them. MCs carry away an amount of unsigned magnetic helicity similar to the amount estimated for the solar dynamo and that measured in emerging active regions. © 2015, Springer Science+Business Media Dordrecht.
author Dasso, Sergio Ricardo
author_facet Dasso, Sergio Ricardo
author_sort Dasso, Sergio Ricardo
title Magnetic Flux and Helicity of Magnetic Clouds
title_short Magnetic Flux and Helicity of Magnetic Clouds
title_full Magnetic Flux and Helicity of Magnetic Clouds
title_fullStr Magnetic Flux and Helicity of Magnetic Clouds
title_full_unstemmed Magnetic Flux and Helicity of Magnetic Clouds
title_sort magnetic flux and helicity of magnetic clouds
publishDate 2016
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v291_n2_p531_Demoulin
http://hdl.handle.net/20.500.12110/paper_00380938_v291_n2_p531_Demoulin
work_keys_str_mv AT dassosergioricardo magneticfluxandhelicityofmagneticclouds
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