Helicity analysis for expanding magnetic clouds: A case study

Magnetic Clouds (MCs) are the interplanetary counterpart of coronal mass ejections (CMEs). They transport to the interplanetary medium the magnetic flux and helicity released in CMEs by the Sun. At 1 AU from the Sun, MCs are generally modeled as static flux ropes, i.e., considering them as rigid bod...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Nakwacki, Maria Soledad, Dasso, Sergio Ricardo
Publicado:	2005
Materias:	Magnetic clouds Magnetic helicity Magnetic properties Mathematical models Solar radiation Magnetic materials
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n592_p629_Nakwacki http://hdl.handle.net/20.500.12110/paper_03796566_v_n592_p629_Nakwacki
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_03796566_v_n592_p629_Nakwacki
record_format	dspace
spelling	paper:paper_03796566_v_n592_p629_Nakwacki2023-06-08T15:40:44Z Helicity analysis for expanding magnetic clouds: A case study Nakwacki, Maria Soledad Dasso, Sergio Ricardo Magnetic clouds Magnetic helicity Magnetic properties Mathematical models Solar radiation Magnetic clouds Magnetic helicity Magnetic materials Magnetic Clouds (MCs) are the interplanetary counterpart of coronal mass ejections (CMEs). They transport to the interplanetary medium the magnetic flux and helicity released in CMEs by the Sun. At 1 AU from the Sun, MCs are generally modeled as static flux ropes, i.e., considering them as rigid bodies traveling through the solar wind. However, the velocity profile of some MCs presents clear signatures of a significant expansion while observed in situ by a spacecraft in the heliosphere. We present here an analysis of the magnetic structure of an expanding magnetic cloud observed during the raising phase of solar cycle 23 by the spacecraft Wind. We consider a dynamical model, based on a self-similar behavior for the cloud radial velocity. We assume a free expansion for the cloud, and a cylindrical linear force free field (i.e., the Lundquist's field) as the initial conditions for its magnetic configuration. We derive theoretical expressions for the magnetic flux, across a surface perpendicular to the cloud axis, and for the magnetic helicity per unit length along the tube using the self-similar model. Finally, we compute these magnitudes fitting the free parameters of the expanding model to in situ magnetic observations, and compare them with those obtained from the linear force free static model. Fil:Nakwacki, M.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Dasso, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n592_p629_Nakwacki http://hdl.handle.net/20.500.12110/paper_03796566_v_n592_p629_Nakwacki
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Magnetic clouds Magnetic helicity Magnetic properties Mathematical models Solar radiation Magnetic clouds Magnetic helicity Magnetic materials
spellingShingle	Magnetic clouds Magnetic helicity Magnetic properties Mathematical models Solar radiation Magnetic clouds Magnetic helicity Magnetic materials Nakwacki, Maria Soledad Dasso, Sergio Ricardo Helicity analysis for expanding magnetic clouds: A case study
topic_facet	Magnetic clouds Magnetic helicity Magnetic properties Mathematical models Solar radiation Magnetic clouds Magnetic helicity Magnetic materials
description	Magnetic Clouds (MCs) are the interplanetary counterpart of coronal mass ejections (CMEs). They transport to the interplanetary medium the magnetic flux and helicity released in CMEs by the Sun. At 1 AU from the Sun, MCs are generally modeled as static flux ropes, i.e., considering them as rigid bodies traveling through the solar wind. However, the velocity profile of some MCs presents clear signatures of a significant expansion while observed in situ by a spacecraft in the heliosphere. We present here an analysis of the magnetic structure of an expanding magnetic cloud observed during the raising phase of solar cycle 23 by the spacecraft Wind. We consider a dynamical model, based on a self-similar behavior for the cloud radial velocity. We assume a free expansion for the cloud, and a cylindrical linear force free field (i.e., the Lundquist's field) as the initial conditions for its magnetic configuration. We derive theoretical expressions for the magnetic flux, across a surface perpendicular to the cloud axis, and for the magnetic helicity per unit length along the tube using the self-similar model. Finally, we compute these magnitudes fitting the free parameters of the expanding model to in situ magnetic observations, and compare them with those obtained from the linear force free static model.
author	Nakwacki, Maria Soledad Dasso, Sergio Ricardo
author_facet	Nakwacki, Maria Soledad Dasso, Sergio Ricardo
author_sort	Nakwacki, Maria Soledad
title	Helicity analysis for expanding magnetic clouds: A case study
title_short	Helicity analysis for expanding magnetic clouds: A case study
title_full	Helicity analysis for expanding magnetic clouds: A case study
title_fullStr	Helicity analysis for expanding magnetic clouds: A case study
title_full_unstemmed	Helicity analysis for expanding magnetic clouds: A case study
title_sort	helicity analysis for expanding magnetic clouds: a case study
publishDate	2005
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n592_p629_Nakwacki http://hdl.handle.net/20.500.12110/paper_03796566_v_n592_p629_Nakwacki
work_keys_str_mv	AT nakwackimariasoledad helicityanalysisforexpandingmagneticcloudsacasestudy AT dassosergioricardo helicityanalysisforexpandingmagneticcloudsacasestudy
_version_	1768542601077587968

Helicity analysis for expanding magnetic clouds: A case study

Ejemplares similares