Deriving the Coronal Separatrix‐Web With the WSA Model.

Saved in:
Bibliographic Details
Title: Deriving the Coronal Separatrix‐Web With the WSA Model.
Authors: Wallace, Samantha1 (AUTHOR) samantha.wallace@erau.edu, Higginson, Aleida K.2 (AUTHOR), Simpson, David G.2 (AUTHOR), Viall, Nicholeen M.2 (AUTHOR), Wyper, Peter3 (AUTHOR), Arge, C. Nick2 (AUTHOR)
Source: Journal of Geophysical Research. Space Physics. Aug2025, Vol. 130 Issue 8, p1-16. 16p.
Subject Terms: Solar wind, Solar magnetic fields, Rotation of the Sun, Space environment, Sun, Electric field strength
Abstract: We demonstrate a new capability of the Wang‐Sheeley‐Arge (WSA) model to routinely derive the coronal separatrix web (S‐web) as a standard data product. We describe our methodology for deriving the squashing factor (Q $Q$) and we use Carrington rotation (CR) 2109 to illustrate the validation of our output with that derived from the POT3D model. We use the same CR to demonstrate a primary use case of our tool, namely, to interpret in situ observations based on their S‐web origin. We derive the ACE connectivity to the solar surface, and generate a time series that quantitatively relates the solar wind observed at ACE with log(Q) $\log (Q)$ derived at its source region. We demonstrate that all intervals of high log(Q) $\log (Q)$, including one associated with a pseudostreamer, correlate with times when the charge state and abundance measurements at L1 are enhanced and highly structured. This has been predicted for solar wind originating from magnetic separatrix layers and quasi‐separatrix layers at the open‐closed boundary, where closed field plasma is released into the solar wind via interchange reconnection with open fields. Further, we relate log(Q) $\log (Q)$ to expansion factor (fs ${f}_{s}$) and coronal hole boundary distance (θb ${\theta }_{b}$, DCHB), which are longstanding parameters used to empirically derive solar wind speed. We demonstrate that Q $Q$, though related to fs ${f}_{s}$ and DCHB, is a separate metric of the coronal magnetic field topology and a unique probe of solar wind formation. We conclude by highlighting the novel capabilities of this tool, and its future uses for space weather forecasting. Key Points: The WSA model now routinely derives the S‐web, enabling the topological analyses of the coronal magnetic field over several solar cyclesThis tool provides the quantitative relationship between in situ solar wind measurements and S‐web structure in the coronaThis tool opens up new avenues for scientific investigation of the role of the S‐web in solar wind formation [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geophysical Research. Space Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
FullText Text:
  Availability: 0
Header DbId: 8gh
DbLabel: GreenFILE
An: 187572042
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Deriving the Coronal Separatrix‐Web With the WSA Model.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Wallace%2C+Samantha%22">Wallace, Samantha</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> samantha.wallace@erau.edu</i><br /><searchLink fieldCode="AR" term="%22Higginson%2C+Aleida+K%2E%22">Higginson, Aleida K.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Simpson%2C+David+G%2E%22">Simpson, David G.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Viall%2C+Nicholeen+M%2E%22">Viall, Nicholeen M.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Wyper%2C+Peter%22">Wyper, Peter</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Arge%2C+C%2E+Nick%22">Arge, C. Nick</searchLink><relatesTo>2</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Geophysical+Research%2E+Space+Physics%22">Journal of Geophysical Research. Space Physics</searchLink>. Aug2025, Vol. 130 Issue 8, p1-16. 16p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Solar+wind%22">Solar wind</searchLink><br /><searchLink fieldCode="DE" term="%22Solar+magnetic+fields%22">Solar magnetic fields</searchLink><br /><searchLink fieldCode="DE" term="%22Rotation+of+the+Sun%22">Rotation of the Sun</searchLink><br /><searchLink fieldCode="DE" term="%22Space+environment%22">Space environment</searchLink><br /><searchLink fieldCode="DE" term="%22Sun%22">Sun</searchLink><br /><searchLink fieldCode="DE" term="%22Electric+field+strength%22">Electric field strength</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: We demonstrate a new capability of the Wang‐Sheeley‐Arge (WSA) model to routinely derive the coronal separatrix web (S‐web) as a standard data product. We describe our methodology for deriving the squashing factor (Q $Q$) and we use Carrington rotation (CR) 2109 to illustrate the validation of our output with that derived from the POT3D model. We use the same CR to demonstrate a primary use case of our tool, namely, to interpret in situ observations based on their S‐web origin. We derive the ACE connectivity to the solar surface, and generate a time series that quantitatively relates the solar wind observed at ACE with log(Q) $\log (Q)$ derived at its source region. We demonstrate that all intervals of high log(Q) $\log (Q)$, including one associated with a pseudostreamer, correlate with times when the charge state and abundance measurements at L1 are enhanced and highly structured. This has been predicted for solar wind originating from magnetic separatrix layers and quasi‐separatrix layers at the open‐closed boundary, where closed field plasma is released into the solar wind via interchange reconnection with open fields. Further, we relate log(Q) $\log (Q)$ to expansion factor (fs ${f}_{s}$) and coronal hole boundary distance (θb ${\theta }_{b}$, DCHB), which are longstanding parameters used to empirically derive solar wind speed. We demonstrate that Q $Q$, though related to fs ${f}_{s}$ and DCHB, is a separate metric of the coronal magnetic field topology and a unique probe of solar wind formation. We conclude by highlighting the novel capabilities of this tool, and its future uses for space weather forecasting. Key Points: The WSA model now routinely derives the S‐web, enabling the topological analyses of the coronal magnetic field over several solar cyclesThis tool provides the quantitative relationship between in situ solar wind measurements and S‐web structure in the coronaThis tool opens up new avenues for scientific investigation of the role of the S‐web in solar wind formation [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Geophysical Research. Space Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=8gh&AN=187572042
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1029/2025JA033743
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 16
        StartPage: 1
    Subjects:
      – SubjectFull: Solar wind
        Type: general
      – SubjectFull: Solar magnetic fields
        Type: general
      – SubjectFull: Rotation of the Sun
        Type: general
      – SubjectFull: Space environment
        Type: general
      – SubjectFull: Sun
        Type: general
      – SubjectFull: Electric field strength
        Type: general
    Titles:
      – TitleFull: Deriving the Coronal Separatrix‐Web With the WSA Model.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Wallace, Samantha
      – PersonEntity:
          Name:
            NameFull: Higginson, Aleida K.
      – PersonEntity:
          Name:
            NameFull: Simpson, David G.
      – PersonEntity:
          Name:
            NameFull: Viall, Nicholeen M.
      – PersonEntity:
          Name:
            NameFull: Wyper, Peter
      – PersonEntity:
          Name:
            NameFull: Arge, C. Nick
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 08
              Text: Aug2025
              Type: published
              Y: 2025
          Identifiers:
            – Type: issn-print
              Value: 21699380
          Numbering:
            – Type: volume
              Value: 130
            – Type: issue
              Value: 8
          Titles:
            – TitleFull: Journal of Geophysical Research. Space Physics
              Type: main
ResultId 1