Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081

Using differential emission measure tomography (DEMT) based on time series of EUV images, we carry out a quantitative comparative analysis of the three-dimensional (3D) structure of the electron density and temperature of the inner corona (r<1.25R⊙) between two specific rotations selected from th...

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Detalles Bibliográficos
Publicado: 2017
Materias:
Corona, E
Corona, Structures
Solar Cycle, Observations
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v292_n10_p_Lloveras
http://hdl.handle.net/20.500.12110/paper_00380938_v292_n10_p_Lloveras
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00380938_v292_n10_p_Lloveras
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spelling paper:paper_00380938_v292_n10_p_Lloveras2023-06-08T15:02:55Z Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081 Corona, E Corona, Structures Solar Cycle, Observations Using differential emission measure tomography (DEMT) based on time series of EUV images, we carry out a quantitative comparative analysis of the three-dimensional (3D) structure of the electron density and temperature of the inner corona (r<1.25R⊙) between two specific rotations selected from the last two solar minima, namely Carrington Rotations (CR)1915 and CR-2081. The analysis places error bars on the results because of the systematic uncertainty of the sources. While the results for CR-2081 are characterized by a remarkable north–south symmetry, the southern hemisphere for CR-1915 exhibits higher densities and temperatures than the northern hemisphere. The core region of the streamer belt in both rotations is found to be populated by structures whose temperature decreases with height (called “down loops” in our previous articles). They are characterized by plasma β≳ 1 , and may be the result of the efficient dissipation of Alfvén waves at low coronal heights. The comparative analysis reveals that the low latitudes of the equatorial streamer belt of CR-1915 exhibit higher densities than for CR-2081. This cannot be explained by the systematic uncertainties. In addition, the southern hemisphere of the streamer belt of CR-1915 is characterized by higher temperatures and density scale heights than for CR-2081. On the other hand, the coronal hole region of CR-1915 shows lower temperatures than for CR-2081. The reported differences are in the range ≈10–25%, depending on the specific physical quantity and region that is compared, as fully detailed in the analysis. For other regions and/or physical quantities, the uncertainties do not allow assessing the thermodynamical differences between the two rotations. Future investigation will involve a DEMT analysis of other Carrington rotations selected from both epochs, and also a comparison of their tomographic reconstructions with magnetohydrodynamical simulations of the inner corona. © 2017, Springer Science+Business Media B.V. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v292_n10_p_Lloveras http://hdl.handle.net/20.500.12110/paper_00380938_v292_n10_p_Lloveras
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Corona, E
Corona, Structures
Solar Cycle, Observations
spellingShingle Corona, E
Corona, Structures
Solar Cycle, Observations
Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
topic_facet Corona, E
Corona, Structures
Solar Cycle, Observations
description Using differential emission measure tomography (DEMT) based on time series of EUV images, we carry out a quantitative comparative analysis of the three-dimensional (3D) structure of the electron density and temperature of the inner corona (r<1.25R⊙) between two specific rotations selected from the last two solar minima, namely Carrington Rotations (CR)1915 and CR-2081. The analysis places error bars on the results because of the systematic uncertainty of the sources. While the results for CR-2081 are characterized by a remarkable north–south symmetry, the southern hemisphere for CR-1915 exhibits higher densities and temperatures than the northern hemisphere. The core region of the streamer belt in both rotations is found to be populated by structures whose temperature decreases with height (called “down loops” in our previous articles). They are characterized by plasma β≳ 1 , and may be the result of the efficient dissipation of Alfvén waves at low coronal heights. The comparative analysis reveals that the low latitudes of the equatorial streamer belt of CR-1915 exhibit higher densities than for CR-2081. This cannot be explained by the systematic uncertainties. In addition, the southern hemisphere of the streamer belt of CR-1915 is characterized by higher temperatures and density scale heights than for CR-2081. On the other hand, the coronal hole region of CR-1915 shows lower temperatures than for CR-2081. The reported differences are in the range ≈10–25%, depending on the specific physical quantity and region that is compared, as fully detailed in the analysis. For other regions and/or physical quantities, the uncertainties do not allow assessing the thermodynamical differences between the two rotations. Future investigation will involve a DEMT analysis of other Carrington rotations selected from both epochs, and also a comparison of their tomographic reconstructions with magnetohydrodynamical simulations of the inner corona. © 2017, Springer Science+Business Media B.V.
title Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
title_short Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
title_full Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
title_fullStr Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
title_full_unstemmed Comparative Study of the Three-Dimensional Thermodynamical Structure of the Inner Corona of Solar Minimum Carrington Rotations 1915 and 2081
title_sort comparative study of the three-dimensional thermodynamical structure of the inner corona of solar minimum carrington rotations 1915 and 2081
publishDate 2017
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00380938_v292_n10_p_Lloveras
http://hdl.handle.net/20.500.12110/paper_00380938_v292_n10_p_Lloveras
_version_ 1768542979180462080

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