Magnetic clouds along the solar cycle: Expansion and magnetic helicity
Magnetic clouds (MCs) are objects of extreme importance in the heliosphere. They have a major role on releasing magnetic helicity from the Sun (with crucial consequences on the solar dynamo), they are the hugest transient object in the interplanetary medium, and the main actors for the Sun-Earth cou...
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paper:paper_17439213_v7_nS286_p139_Dasso2023-06-08T16:28:05Z Magnetic clouds along the solar cycle: Expansion and magnetic helicity Dasso, Sergio Ricardo Gulisano, Adriana María coronal mass ejections (CMEs) interplanetary medium magnetic clouds magnetic fields plasmas solar wind Magnetic clouds (MCs) are objects of extreme importance in the heliosphere. They have a major role on releasing magnetic helicity from the Sun (with crucial consequences on the solar dynamo), they are the hugest transient object in the interplanetary medium, and the main actors for the Sun-Earth coupling. The comparison between models and observations is beginning to clarify several open questions on MCs, such as their internal magnetic configuration and their interaction with the ambient solar wind. Due to the decay of the solar wind pressure with the distance to the Sun, MCs are typically in expansion. However, their detailed and local expansion properties depend on their environment plasma properties. On the other hand, while it is well known that the solar cycle determines several properties of the heliosphere, the effects of the cycle on MC properties are not so well understood. In this work we review two major properties of MCs: (i) their expansion, and (ii) the magnetic flux and helicity that they transport through the interplanetary medium. We find that the amount of magnetic flux and helicity released via MCs during the last solar minimum (years 2007-2009) was significantly lower than in the previous one (years 1995-1997). Moreover, both MC size and mean velocity are in phase with the solar cycle while the expansion rate is weakly variable and has no relationship with the cycle. © 2012 International Astronomical Union. Fil:Dasso, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gulisano, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_17439213_v7_nS286_p139_Dasso http://hdl.handle.net/20.500.12110/paper_17439213_v7_nS286_p139_Dasso |
| 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 (CMEs) interplanetary medium magnetic clouds magnetic fields plasmas solar wind |
| spellingShingle |
coronal mass ejections (CMEs) interplanetary medium magnetic clouds magnetic fields plasmas solar wind Dasso, Sergio Ricardo Gulisano, Adriana María Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| topic_facet |
coronal mass ejections (CMEs) interplanetary medium magnetic clouds magnetic fields plasmas solar wind |
| description |
Magnetic clouds (MCs) are objects of extreme importance in the heliosphere. They have a major role on releasing magnetic helicity from the Sun (with crucial consequences on the solar dynamo), they are the hugest transient object in the interplanetary medium, and the main actors for the Sun-Earth coupling. The comparison between models and observations is beginning to clarify several open questions on MCs, such as their internal magnetic configuration and their interaction with the ambient solar wind. Due to the decay of the solar wind pressure with the distance to the Sun, MCs are typically in expansion. However, their detailed and local expansion properties depend on their environment plasma properties. On the other hand, while it is well known that the solar cycle determines several properties of the heliosphere, the effects of the cycle on MC properties are not so well understood. In this work we review two major properties of MCs: (i) their expansion, and (ii) the magnetic flux and helicity that they transport through the interplanetary medium. We find that the amount of magnetic flux and helicity released via MCs during the last solar minimum (years 2007-2009) was significantly lower than in the previous one (years 1995-1997). Moreover, both MC size and mean velocity are in phase with the solar cycle while the expansion rate is weakly variable and has no relationship with the cycle. © 2012 International Astronomical Union. |
| author |
Dasso, Sergio Ricardo Gulisano, Adriana María |
| author_facet |
Dasso, Sergio Ricardo Gulisano, Adriana María |
| author_sort |
Dasso, Sergio Ricardo |
| title |
Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| title_short |
Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| title_full |
Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| title_fullStr |
Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| title_full_unstemmed |
Magnetic clouds along the solar cycle: Expansion and magnetic helicity |
| title_sort |
magnetic clouds along the solar cycle: expansion and magnetic helicity |
| publishDate |
2011 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_17439213_v7_nS286_p139_Dasso http://hdl.handle.net/20.500.12110/paper_17439213_v7_nS286_p139_Dasso |
| work_keys_str_mv |
AT dassosergioricardo magneticcloudsalongthesolarcycleexpansionandmagnetichelicity AT gulisanoadrianamaria magneticcloudsalongthesolarcycleexpansionandmagnetichelicity |
| _version_ |
1768541913605996544 |