Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations
A potential field solution is widely used to extrapolate the coronal magnetic field above the Sun’s surface to a certain height. This model applies the current-free approximation and assumes that the magnetic field is entirely radial beyond the source surface height, which is defined as the radial d...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/ad3547 |
| _version_ | 1797225669615157248 |
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| author | Zhenguang Huang Gábor Tóth Jia Huang Nishtha Sachdeva Bart van der Holst Ward B. Manchester |
| author_facet | Zhenguang Huang Gábor Tóth Jia Huang Nishtha Sachdeva Bart van der Holst Ward B. Manchester |
| author_sort | Zhenguang Huang |
| collection | DOAJ |
| description | A potential field solution is widely used to extrapolate the coronal magnetic field above the Sun’s surface to a certain height. This model applies the current-free approximation and assumes that the magnetic field is entirely radial beyond the source surface height, which is defined as the radial distance from the center of the Sun. Even though the source surface is commonly specified at 2.5 R _s (solar radii), previous studies have suggested that this value is not optimal in all cases. In this study, we propose a novel approach to specify the source surface height by comparing the areas of the open magnetic field regions from the potential field solution with predictions made by a magnetohydrodynamic model, in our case the Alfvén Wave Solar atmosphere Model. We find that the adjusted source surface height is significantly less than 2.5 R _s near solar minimum and slightly larger than 2.5 R _s near solar maximum. We also report that the adjusted source surface height can provide a better open flux agreement with the observations near the solar minimum, while the comparison near the solar maximum is slightly worse. |
| first_indexed | 2024-04-24T14:12:41Z |
| format | Article |
| id | doaj.art-2993caf8514e4097a4c5fc401384ab33 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-04-24T14:12:41Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-2993caf8514e4097a4c5fc401384ab332024-04-03T08:57:59ZengIOP PublishingThe Astrophysical Journal Letters2041-82052024-01-019651L110.3847/2041-8213/ad3547Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic SimulationsZhenguang Huang0https://orcid.org/0000-0003-1674-0647Gábor Tóth1https://orcid.org/0000-0001-8459-2100Jia Huang2https://orcid.org/0000-0002-9954-4707Nishtha Sachdeva3https://orcid.org/0000-0001-9114-6133Bart van der Holst4https://orcid.org/0000-0001-5260-3944Ward B. Manchester5https://orcid.org/0000-0003-0472-9408Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA ; zghuang@umich.eduClimate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA ; zghuang@umich.eduSpace Sciences Laboratory, University of California , Berkeley, CA 94720, USAClimate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA ; zghuang@umich.eduClimate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA ; zghuang@umich.eduClimate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA ; zghuang@umich.eduA potential field solution is widely used to extrapolate the coronal magnetic field above the Sun’s surface to a certain height. This model applies the current-free approximation and assumes that the magnetic field is entirely radial beyond the source surface height, which is defined as the radial distance from the center of the Sun. Even though the source surface is commonly specified at 2.5 R _s (solar radii), previous studies have suggested that this value is not optimal in all cases. In this study, we propose a novel approach to specify the source surface height by comparing the areas of the open magnetic field regions from the potential field solution with predictions made by a magnetohydrodynamic model, in our case the Alfvén Wave Solar atmosphere Model. We find that the adjusted source surface height is significantly less than 2.5 R _s near solar minimum and slightly larger than 2.5 R _s near solar maximum. We also report that the adjusted source surface height can provide a better open flux agreement with the observations near the solar minimum, while the comparison near the solar maximum is slightly worse.https://doi.org/10.3847/2041-8213/ad3547Solar magnetic fieldsSolar cycleMagnetohydrodynamics |
| spellingShingle | Zhenguang Huang Gábor Tóth Jia Huang Nishtha Sachdeva Bart van der Holst Ward B. Manchester Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations The Astrophysical Journal Letters Solar magnetic fields Solar cycle Magnetohydrodynamics |
| title | Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations |
| title_full | Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations |
| title_fullStr | Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations |
| title_full_unstemmed | Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations |
| title_short | Adjusting the Potential Field Source Surface Height Based on Magnetohydrodynamic Simulations |
| title_sort | adjusting the potential field source surface height based on magnetohydrodynamic simulations |
| topic | Solar magnetic fields Solar cycle Magnetohydrodynamics |
| url | https://doi.org/10.3847/2041-8213/ad3547 |
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