View in EDS

Extreme Birkeland Currents Are More Likely During Geomagnetic Storms on the Dayside of the Earth.

Saved in:
Bibliographic Details
Title: Extreme Birkeland Currents Are More Likely During Geomagnetic Storms on the Dayside of the Earth.
Authors: Coxon, John C.1 (AUTHOR) work@johncoxon.co.uk, Chisham, Gareth2 (AUTHOR), Freeman, Mervyn P.2 (AUTHOR), Forsyth, Colin3 (AUTHOR), Walach, Maria‐Theresia4 (AUTHOR), Murphy, Kyle R.1 (AUTHOR), Vines, Sarah K.5 (AUTHOR), Anderson, Brian J.5 (AUTHOR), Smith, Andrew W.1 (AUTHOR), Fogg, Alexandra R.6 (AUTHOR)
Source: Journal of Geophysical Research. Space Physics. Dec2023, Vol. 128 Issue 12, p1-16. 16p.
Subject Terms: *Geomagnetism, *Magnetic storms, *Earthflows, Space environment, Electric currents, Distribution (Probability theory), Electron field emission, Large deviations (Mathematics)
Abstract: We examine the statistical distribution of large‐scale Birkeland currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment in four unique categories of geomagnetic activity for the first time: quiet times, storm times, quiet‐time substorms, and storm‐time substorms. A novel method is employed to sort data into one of these four categories, and the categorizations are provided for future research. The mean current density is largest during substorms and its standard deviation is largest during geomagnetic storms. Current densities which are above a low threshold are more likely during substorms, but extreme currents are far more likely during geomagnetic storms, consistent with a paradigm in which geomagnetic storms represent periods of enhanced variability over quiet times. We demonstrate that extreme currents are most likely to flow within the Region 2 current during geomagnetic storms. This is unexpected in a paradigm of the current systems in which Region 1 current is generally larger. Plain Language Summary: We take measurements from a set of 66 spacecraft orbiting Earth to look at electric currents that flow along Earth's magnetic field lines. We look at different types of space weather called "geomagnetic storms" and "substorms," and combine methods to detect when those types of space weather happen. We use our combined method to separate our measurements into the different types of space weather, and then we look at how strong the currents are during each type of space weather. We plot histograms of the strengths and then use those histograms to work out the underlying mathematics of the strengths: we can then plot further graphs showing how those underlying mathematics change. We then work out when the very strongest currents are likely to flow, and during which type of space weather this occurs, which is useful both for understanding the system and for mitigating against the risks of space weather. Key Points: Geomagnetic storms are more likely than substorms to drive extreme field‐aligned current densitiesExtreme current densities are most likely on the dayside and least likely within 3 hr of midnightThe highest probabilities of extreme current densities occur in Region 2 currents during geomagnetic storms [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: 174408006
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Extreme Birkeland Currents Are More Likely During Geomagnetic Storms on the Dayside of the Earth.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Coxon%2C+John+C%2E%22">Coxon, John C.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> work@johncoxon.co.uk</i><br /><searchLink fieldCode="AR" term="%22Chisham%2C+Gareth%22">Chisham, Gareth</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Freeman%2C+Mervyn+P%2E%22">Freeman, Mervyn P.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Forsyth%2C+Colin%22">Forsyth, Colin</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Walach%2C+Maria‐Theresia%22">Walach, Maria‐Theresia</searchLink><relatesTo>4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Murphy%2C+Kyle+R%2E%22">Murphy, Kyle R.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Vines%2C+Sarah+K%2E%22">Vines, Sarah K.</searchLink><relatesTo>5</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Anderson%2C+Brian+J%2E%22">Anderson, Brian J.</searchLink><relatesTo>5</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Smith%2C+Andrew+W%2E%22">Smith, Andrew W.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Fogg%2C+Alexandra+R%2E%22">Fogg, Alexandra R.</searchLink><relatesTo>6</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>. Dec2023, Vol. 128 Issue 12, p1-16. 16p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Geomagnetism%22">Geomagnetism</searchLink><br />*<searchLink fieldCode="DE" term="%22Magnetic+storms%22">Magnetic storms</searchLink><br />*<searchLink fieldCode="DE" term="%22Earthflows%22">Earthflows</searchLink><br /><searchLink fieldCode="DE" term="%22Space+environment%22">Space environment</searchLink><br /><searchLink fieldCode="DE" term="%22Electric+currents%22">Electric currents</searchLink><br /><searchLink fieldCode="DE" term="%22Distribution+%28Probability+theory%29%22">Distribution (Probability theory)</searchLink><br /><searchLink fieldCode="DE" term="%22Electron+field+emission%22">Electron field emission</searchLink><br /><searchLink fieldCode="DE" term="%22Large+deviations+%28Mathematics%29%22">Large deviations (Mathematics)</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: We examine the statistical distribution of large‐scale Birkeland currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment in four unique categories of geomagnetic activity for the first time: quiet times, storm times, quiet‐time substorms, and storm‐time substorms. A novel method is employed to sort data into one of these four categories, and the categorizations are provided for future research. The mean current density is largest during substorms and its standard deviation is largest during geomagnetic storms. Current densities which are above a low threshold are more likely during substorms, but extreme currents are far more likely during geomagnetic storms, consistent with a paradigm in which geomagnetic storms represent periods of enhanced variability over quiet times. We demonstrate that extreme currents are most likely to flow within the Region 2 current during geomagnetic storms. This is unexpected in a paradigm of the current systems in which Region 1 current is generally larger. Plain Language Summary: We take measurements from a set of 66 spacecraft orbiting Earth to look at electric currents that flow along Earth's magnetic field lines. We look at different types of space weather called "geomagnetic storms" and "substorms," and combine methods to detect when those types of space weather happen. We use our combined method to separate our measurements into the different types of space weather, and then we look at how strong the currents are during each type of space weather. We plot histograms of the strengths and then use those histograms to work out the underlying mathematics of the strengths: we can then plot further graphs showing how those underlying mathematics change. We then work out when the very strongest currents are likely to flow, and during which type of space weather this occurs, which is useful both for understanding the system and for mitigating against the risks of space weather. Key Points: Geomagnetic storms are more likely than substorms to drive extreme field‐aligned current densitiesExtreme current densities are most likely on the dayside and least likely within 3 hr of midnightThe highest probabilities of extreme current densities occur in Region 2 currents during geomagnetic storms [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=174408006
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1029/2023JA031946
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 16
        StartPage: 1
    Subjects:
      – SubjectFull: Geomagnetism
        Type: general
      – SubjectFull: Magnetic storms
        Type: general
      – SubjectFull: Earthflows
        Type: general
      – SubjectFull: Space environment
        Type: general
      – SubjectFull: Electric currents
        Type: general
      – SubjectFull: Distribution (Probability theory)
        Type: general
      – SubjectFull: Electron field emission
        Type: general
      – SubjectFull: Large deviations (Mathematics)
        Type: general
    Titles:
      – TitleFull: Extreme Birkeland Currents Are More Likely During Geomagnetic Storms on the Dayside of the Earth.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Coxon, John C.
      – PersonEntity:
          Name:
            NameFull: Chisham, Gareth
      – PersonEntity:
          Name:
            NameFull: Freeman, Mervyn P.
      – PersonEntity:
          Name:
            NameFull: Forsyth, Colin
      – PersonEntity:
          Name:
            NameFull: Walach, Maria‐Theresia
      – PersonEntity:
          Name:
            NameFull: Murphy, Kyle R.
      – PersonEntity:
          Name:
            NameFull: Vines, Sarah K.
      – PersonEntity:
          Name:
            NameFull: Anderson, Brian J.
      – PersonEntity:
          Name:
            NameFull: Smith, Andrew W.
      – PersonEntity:
          Name:
            NameFull: Fogg, Alexandra R.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 12
              Text: Dec2023
              Type: published
              Y: 2023
          Identifiers:
            – Type: issn-print
              Value: 21699380
          Numbering:
            – Type: volume
              Value: 128
            – Type: issue
              Value: 12
          Titles:
            – TitleFull: Journal of Geophysical Research. Space Physics
              Type: main
ResultId 1