Newly discovered global temperature structures in the quiet sun at solar minimum

Magnetic loops are building blocks of the closed-field corona. While active region loops are readily seen in images taken at EUV and X-ray wavelengths, quiet-Sun (QS) loops are seldom identifiable and are therefore difficult to study on an individual basis. The first analysis of solar minimum (Carri...

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Guardado en:
Detalles Bibliográficos
Publicado: 2012
Materias:
Sun: corona
Sun: magnetic topology
Sun: UV radiation
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v755_n2_p_Huang
http://hdl.handle.net/20.500.12110/paper_0004637X_v755_n2_p_Huang
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_0004637X_v755_n2_p_Huang
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spelling paper:paper_0004637X_v755_n2_p_Huang2023-06-08T14:29:07Z Newly discovered global temperature structures in the quiet sun at solar minimum Sun: corona Sun: magnetic topology Sun: UV radiation Magnetic loops are building blocks of the closed-field corona. While active region loops are readily seen in images taken at EUV and X-ray wavelengths, quiet-Sun (QS) loops are seldom identifiable and are therefore difficult to study on an individual basis. The first analysis of solar minimum (Carrington Rotation 2077) QS coronal loops utilizing a novel technique called the Michigan Loop Diagnostic Technique (MLDT) is presented. This technique combines Differential Emission Measure Tomography and a potential field source surface (PFSS) model, and consists of tracing PFSS field lines through the tomographic grid on which the local differential emission measure is determined. As a result, the electron temperature Te and density Ne at each point along each individual field line can be obtained. Using data from STEREO/EUVI and SOHO/MDI, the MLDT identifies two types of QS loops in the corona: so-called up loops in which the temperature increases with height and so-called down loops in which the temperature decreases with height. Up loops are expected, however, down loops are a surprise, and furthermore, they are ubiquitous in the low-latitude corona. Up loops dominate the QS at higher latitudes. The MLDT allows independent determination of the empirical pressure and density scale heights, and the differences between the two remain to be explained. The down loops appear to be a newly discovered property of the solar minimum corona that may shed light on the physics of coronal heating. The results are shown to be robust to the calibration uncertainties of the EUVI instrument. © © 2012. The American Astronomical Society. All rights reserved.. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v755_n2_p_Huang http://hdl.handle.net/20.500.12110/paper_0004637X_v755_n2_p_Huang
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Sun: corona
Sun: magnetic topology
Sun: UV radiation
spellingShingle Sun: corona
Sun: magnetic topology
Sun: UV radiation
Newly discovered global temperature structures in the quiet sun at solar minimum
topic_facet Sun: corona
Sun: magnetic topology
Sun: UV radiation
description Magnetic loops are building blocks of the closed-field corona. While active region loops are readily seen in images taken at EUV and X-ray wavelengths, quiet-Sun (QS) loops are seldom identifiable and are therefore difficult to study on an individual basis. The first analysis of solar minimum (Carrington Rotation 2077) QS coronal loops utilizing a novel technique called the Michigan Loop Diagnostic Technique (MLDT) is presented. This technique combines Differential Emission Measure Tomography and a potential field source surface (PFSS) model, and consists of tracing PFSS field lines through the tomographic grid on which the local differential emission measure is determined. As a result, the electron temperature Te and density Ne at each point along each individual field line can be obtained. Using data from STEREO/EUVI and SOHO/MDI, the MLDT identifies two types of QS loops in the corona: so-called up loops in which the temperature increases with height and so-called down loops in which the temperature decreases with height. Up loops are expected, however, down loops are a surprise, and furthermore, they are ubiquitous in the low-latitude corona. Up loops dominate the QS at higher latitudes. The MLDT allows independent determination of the empirical pressure and density scale heights, and the differences between the two remain to be explained. The down loops appear to be a newly discovered property of the solar minimum corona that may shed light on the physics of coronal heating. The results are shown to be robust to the calibration uncertainties of the EUVI instrument. © © 2012. The American Astronomical Society. All rights reserved..
title Newly discovered global temperature structures in the quiet sun at solar minimum
title_short Newly discovered global temperature structures in the quiet sun at solar minimum
title_full Newly discovered global temperature structures in the quiet sun at solar minimum
title_fullStr Newly discovered global temperature structures in the quiet sun at solar minimum
title_full_unstemmed Newly discovered global temperature structures in the quiet sun at solar minimum
title_sort newly discovered global temperature structures in the quiet sun at solar minimum
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v755_n2_p_Huang
http://hdl.handle.net/20.500.12110/paper_0004637X_v755_n2_p_Huang
_version_ 1768545445089378304

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