Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds
We have analyzed the long-term evolution of two active regions (ARs) from their emergence through their decay using observations from several instruments on board SoHO (MDI, EIT and LASCO) and Yohkoh/SXT. We have computed the evolution of the relative coronal magnetic helicity combining data from MD...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_0004640X_v290_n3-4_p319_Mandrini |
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todo:paper_0004640X_v290_n3-4_p319_Mandrini2023-10-03T14:02:59Z Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds Mandrini, C.H. Démoulin, P. Van Driel-Gesztelyi, L. Green, L.M. López Fuentes, M.C. Coronal mass ejections (CMEs) Magnetic field Sun: corona We have analyzed the long-term evolution of two active regions (ARs) from their emergence through their decay using observations from several instruments on board SoHO (MDI, EIT and LASCO) and Yohkoh/SXT. We have computed the evolution of the relative coronal magnetic helicity combining data from MDI and SXT with a linear force-free model of the coronal magnetic field. Next, we have computed the injection of helicity by surface differential rotation using MDI magnetic maps. To estimate the depletion of helicity we have counted all the CMEs of which these ARs have been the source, and we have evaluated their magnetic helicity assuming a one to one correspondence with magnetic clouds with an average helicity contain. When these three values (variation of coronal magnetic helicity, injection by differential rotation and ejection via CMEs) are compared, we find that surface differential rotation is a minor contributor to the helicity budget since CMEs carry away at least 10 times more helicity than the one differential rotation can provide. Therefore, the magnetic helicity flux needed in the global balance should come from localized photospheric motions that, at least partially, reflect the emergence of twisted flux tubes. We estimate that the total helicity carried away in CMEs can be provided by the end-to-end helicity of the flux tubes forming these ARs. Therefore, we conclude that most of the helicity ejected in CMEs is generated below the photosphere and emerges with the magnetic flux. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0004640X_v290_n3-4_p319_Mandrini |
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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) Magnetic field Sun: corona |
| spellingShingle |
Coronal mass ejections (CMEs) Magnetic field Sun: corona Mandrini, C.H. Démoulin, P. Van Driel-Gesztelyi, L. Green, L.M. López Fuentes, M.C. Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| topic_facet |
Coronal mass ejections (CMEs) Magnetic field Sun: corona |
| description |
We have analyzed the long-term evolution of two active regions (ARs) from their emergence through their decay using observations from several instruments on board SoHO (MDI, EIT and LASCO) and Yohkoh/SXT. We have computed the evolution of the relative coronal magnetic helicity combining data from MDI and SXT with a linear force-free model of the coronal magnetic field. Next, we have computed the injection of helicity by surface differential rotation using MDI magnetic maps. To estimate the depletion of helicity we have counted all the CMEs of which these ARs have been the source, and we have evaluated their magnetic helicity assuming a one to one correspondence with magnetic clouds with an average helicity contain. When these three values (variation of coronal magnetic helicity, injection by differential rotation and ejection via CMEs) are compared, we find that surface differential rotation is a minor contributor to the helicity budget since CMEs carry away at least 10 times more helicity than the one differential rotation can provide. Therefore, the magnetic helicity flux needed in the global balance should come from localized photospheric motions that, at least partially, reflect the emergence of twisted flux tubes. We estimate that the total helicity carried away in CMEs can be provided by the end-to-end helicity of the flux tubes forming these ARs. Therefore, we conclude that most of the helicity ejected in CMEs is generated below the photosphere and emerges with the magnetic flux. |
| format |
JOUR |
| author |
Mandrini, C.H. Démoulin, P. Van Driel-Gesztelyi, L. Green, L.M. López Fuentes, M.C. |
| author_facet |
Mandrini, C.H. Démoulin, P. Van Driel-Gesztelyi, L. Green, L.M. López Fuentes, M.C. |
| author_sort |
Mandrini, C.H. |
| title |
Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| title_short |
Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| title_full |
Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| title_fullStr |
Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| title_full_unstemmed |
Magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| title_sort |
magnetic helicity budget of solar-active regions from the photosphere to magnetic clouds |
| url |
http://hdl.handle.net/20.500.12110/paper_0004640X_v290_n3-4_p319_Mandrini |
| work_keys_str_mv |
AT mandrinich magnetichelicitybudgetofsolaractiveregionsfromthephotospheretomagneticclouds AT demoulinp magnetichelicitybudgetofsolaractiveregionsfromthephotospheretomagneticclouds AT vandrielgesztelyil magnetichelicitybudgetofsolaractiveregionsfromthephotospheretomagneticclouds AT greenlm magnetichelicitybudgetofsolaractiveregionsfromthephotospheretomagneticclouds AT lopezfuentesmc magnetichelicitybudgetofsolaractiveregionsfromthephotospheretomagneticclouds |
| _version_ |
1782023961644630016 |