The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution

We analyze the evolution of coronal plasma upflows from the edges of AR 10978, which has the best limb-to-limb data coverage with Hinode's EUV Imaging Spectrometer (EIS). We find that the observed evolution is largely due to the solar rotation progressively changing the viewpoint of nearly stat...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autor principal:	Mandrini, Cristina Hemilse
Publicado:	2013
Materias:	Active regions, magnetic fields Active regions, velocity field Corona, active Spectral line, broadening
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v283_n2_p341_Demoulin http://hdl.handle.net/20.500.12110/paper_00380938_v283_n2_p341_Demoulin
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00380938_v283_n2_p341_Demoulin
record_format	dspace
spelling	paper:paper_00380938_v283_n2_p341_Demoulin2023-06-08T15:02:49Z The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution Mandrini, Cristina Hemilse Active regions, magnetic fields Active regions, velocity field Corona, active Spectral line, broadening We analyze the evolution of coronal plasma upflows from the edges of AR 10978, which has the best limb-to-limb data coverage with Hinode's EUV Imaging Spectrometer (EIS). We find that the observed evolution is largely due to the solar rotation progressively changing the viewpoint of nearly stationary flows. From the systematic changes in the upflow regions as a function of distance from disc center, we deduce their 3D geometrical properties as inclination and angular spread in three coronal lines (Si vii, Fe xii, and Fe xv). In agreement with magnetic extrapolations, we find that the flows are thin, fan-like structures rooted in quasi separatrix layers (QSLs). The fans are tilted away from the AR center. The highest plasma velocities in these three spectral lines have similar magnitudes and their heights increase with temperature. The spatial location and extent of the upflow regions in the Si vii, Fe xii, and Fe xv lines are different owing to i) temperature stratification and ii) line of sight integration of the spectral profiles with significantly different backgrounds. We conclude that we sample the same flows at different temperatures. Further, we find that the evolution of line widths during the disc passage is compatible with a broad range of velocities in the flows. Everything considered, our results are compatible with the AR upflows originating from reconnections along QSLs between over-pressure AR loops and neighboring under-pressure loops. The flows are driven along magnetic field lines by a pressure gradient in a stratified atmosphere. Our interpretation of the above results is that, at any given time, we observe the superposition of flows created by successive reconnections, leading to a broad velocity distribution. © 2013 Springer Science+Business Media Dordrecht. Fil:Mandrini, C.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v283_n2_p341_Demoulin http://hdl.handle.net/20.500.12110/paper_00380938_v283_n2_p341_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	Active regions, magnetic fields Active regions, velocity field Corona, active Spectral line, broadening
spellingShingle	Active regions, magnetic fields Active regions, velocity field Corona, active Spectral line, broadening Mandrini, Cristina Hemilse The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
topic_facet	Active regions, magnetic fields Active regions, velocity field Corona, active Spectral line, broadening
description	We analyze the evolution of coronal plasma upflows from the edges of AR 10978, which has the best limb-to-limb data coverage with Hinode's EUV Imaging Spectrometer (EIS). We find that the observed evolution is largely due to the solar rotation progressively changing the viewpoint of nearly stationary flows. From the systematic changes in the upflow regions as a function of distance from disc center, we deduce their 3D geometrical properties as inclination and angular spread in three coronal lines (Si vii, Fe xii, and Fe xv). In agreement with magnetic extrapolations, we find that the flows are thin, fan-like structures rooted in quasi separatrix layers (QSLs). The fans are tilted away from the AR center. The highest plasma velocities in these three spectral lines have similar magnitudes and their heights increase with temperature. The spatial location and extent of the upflow regions in the Si vii, Fe xii, and Fe xv lines are different owing to i) temperature stratification and ii) line of sight integration of the spectral profiles with significantly different backgrounds. We conclude that we sample the same flows at different temperatures. Further, we find that the evolution of line widths during the disc passage is compatible with a broad range of velocities in the flows. Everything considered, our results are compatible with the AR upflows originating from reconnections along QSLs between over-pressure AR loops and neighboring under-pressure loops. The flows are driven along magnetic field lines by a pressure gradient in a stratified atmosphere. Our interpretation of the above results is that, at any given time, we observe the superposition of flows created by successive reconnections, leading to a broad velocity distribution. © 2013 Springer Science+Business Media Dordrecht.
author	Mandrini, Cristina Hemilse
author_facet	Mandrini, Cristina Hemilse
author_sort	Mandrini, Cristina Hemilse
title	The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
title_short	The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
title_full	The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
title_fullStr	The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
title_full_unstemmed	The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution
title_sort	3d geometry of active region upflows deduced from their limb-to-limb evolution
publishDate	2013
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v283_n2_p341_Demoulin http://hdl.handle.net/20.500.12110/paper_00380938_v283_n2_p341_Demoulin
work_keys_str_mv	AT mandrinicristinahemilse the3dgeometryofactiveregionupflowsdeducedfromtheirlimbtolimbevolution AT mandrinicristinahemilse 3dgeometryofactiveregionupflowsdeducedfromtheirlimbtolimbevolution
_version_	1768546245756846080

The 3D Geometry of Active Region Upflows Deduced from Their Limb-to-Limb Evolution

Ejemplares similares