In situ properties of small and large flux ropes in the solar wind

Two populations of twisted magnetic field tubes, or flux ropes (hereafter, FRs), are detected by in situ measurements in the solar wind. While small FRs are crossed by the observing spacecraft within few hours, with a radius typically less than 0.1 AU, larger FRs, or magnetic clouds (hereafter, MCs)...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autor principal:	Dasso, Sergio Ricardo
Publicado:	2014
Materias:	Flux ropes Interplanetary Coronal Mass Ejections Magnetic clouds Solar Wind
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_21699380_v119_n9_p7088_Janvier http://hdl.handle.net/20.500.12110/paper_21699380_v119_n9_p7088_Janvier
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_21699380_v119_n9_p7088_Janvier
record_format	dspace
spelling	paper:paper_21699380_v119_n9_p7088_Janvier2023-06-08T16:34:48Z In situ properties of small and large flux ropes in the solar wind Dasso, Sergio Ricardo Flux ropes Interplanetary Coronal Mass Ejections Magnetic clouds Solar Wind Two populations of twisted magnetic field tubes, or flux ropes (hereafter, FRs), are detected by in situ measurements in the solar wind. While small FRs are crossed by the observing spacecraft within few hours, with a radius typically less than 0.1 AU, larger FRs, or magnetic clouds (hereafter, MCs), have durations of about half a day. The main aim of this study is to compare the properties of both populations of FRs observed by the Wind spacecraft at 1 AU. To do so, we use standard correlation techniques for the FR parameters, as well as histograms and more refined statistical methods. Although several properties seem at first different for small FRs and MCs, we show that they are actually governed by the same propagation physics. For example, we observe no in situ signatures of expansion for small FRs, contrary to MCs. We demonstrate that this result is in fact expected: small FRs expand similar to MCs, as a consequence of a total pressure balance with the surrounding medium, but the expansion signature is well hidden by velocity fluctuations. Next, we find that the FR radius, velocity, and magnetic field strength are all positively correlated, with correlation factors than can reach a value >0.5. This result indicates a remnant trace of the FR ejection process from the corona. We also find a larger FR radius at the apex than at the legs (up to 3 times larger at the apex), for FR observed at 1 AU. Finally, assuming that the detected FRs have a large-scale configuration in the heliosphere, we derived the mean axis shape from the probability distribution of the axis orientation. We therefore interpret the small FR and MC properties in a common framework of FRs interacting with the solar wind, and we disentangle the physics present behind their common and different features. © 2014. American Geophysical Union. All Rights Reserved. Fil:Dasso, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_21699380_v119_n9_p7088_Janvier http://hdl.handle.net/20.500.12110/paper_21699380_v119_n9_p7088_Janvier
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Flux ropes Interplanetary Coronal Mass Ejections Magnetic clouds Solar Wind
spellingShingle	Flux ropes Interplanetary Coronal Mass Ejections Magnetic clouds Solar Wind Dasso, Sergio Ricardo In situ properties of small and large flux ropes in the solar wind
topic_facet	Flux ropes Interplanetary Coronal Mass Ejections Magnetic clouds Solar Wind
description	Two populations of twisted magnetic field tubes, or flux ropes (hereafter, FRs), are detected by in situ measurements in the solar wind. While small FRs are crossed by the observing spacecraft within few hours, with a radius typically less than 0.1 AU, larger FRs, or magnetic clouds (hereafter, MCs), have durations of about half a day. The main aim of this study is to compare the properties of both populations of FRs observed by the Wind spacecraft at 1 AU. To do so, we use standard correlation techniques for the FR parameters, as well as histograms and more refined statistical methods. Although several properties seem at first different for small FRs and MCs, we show that they are actually governed by the same propagation physics. For example, we observe no in situ signatures of expansion for small FRs, contrary to MCs. We demonstrate that this result is in fact expected: small FRs expand similar to MCs, as a consequence of a total pressure balance with the surrounding medium, but the expansion signature is well hidden by velocity fluctuations. Next, we find that the FR radius, velocity, and magnetic field strength are all positively correlated, with correlation factors than can reach a value >0.5. This result indicates a remnant trace of the FR ejection process from the corona. We also find a larger FR radius at the apex than at the legs (up to 3 times larger at the apex), for FR observed at 1 AU. Finally, assuming that the detected FRs have a large-scale configuration in the heliosphere, we derived the mean axis shape from the probability distribution of the axis orientation. We therefore interpret the small FR and MC properties in a common framework of FRs interacting with the solar wind, and we disentangle the physics present behind their common and different features. © 2014. American Geophysical Union. All Rights Reserved.
author	Dasso, Sergio Ricardo
author_facet	Dasso, Sergio Ricardo
author_sort	Dasso, Sergio Ricardo
title	In situ properties of small and large flux ropes in the solar wind
title_short	In situ properties of small and large flux ropes in the solar wind
title_full	In situ properties of small and large flux ropes in the solar wind
title_fullStr	In situ properties of small and large flux ropes in the solar wind
title_full_unstemmed	In situ properties of small and large flux ropes in the solar wind
title_sort	in situ properties of small and large flux ropes in the solar wind
publishDate	2014
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_21699380_v119_n9_p7088_Janvier http://hdl.handle.net/20.500.12110/paper_21699380_v119_n9_p7088_Janvier
work_keys_str_mv	AT dassosergioricardo insitupropertiesofsmallandlargefluxropesinthesolarwind
_version_	1768544061537386496

In situ properties of small and large flux ropes in the solar wind

Ejemplares similares