A comparison of methods to compute the rate of horizontal geomagnetic field variation.

Saved in:
Bibliographic Details
Title: A comparison of methods to compute the rate of horizontal geomagnetic field variation.
Authors: Fielding, Samuel A.1 (AUTHOR) sfieldin@ed.ac.uk, Livermore, Philip W.2 (AUTHOR), Beggan, Ciarán D.3 (AUTHOR), Whaler, Kathryn A.1 (AUTHOR), Richardson, Gemma S.3 (AUTHOR)
Source: Annales Geophysicae (ANGEO) (09927689). 2025, Vol. 43 Issue 2, p687-700. 14p.
Subject Terms: *Geomagnetism, *Geomagnetic variations, *Space environment, *Acquisition of data
Abstract: The rate of change of the horizontal external magnetic field is often used as a proxy for space weather activity and in particular for estimating geomagnetically induced currents (GICs) in high voltage power grids. This paper compares two commonly adopted methods for computing this rate of change: (1) the difference between consecutive measurements in the magnitude of the horizontal magnetic field, H′ , and (2) the combined difference in the magnitude in the northward and eastward directions, usually denoted R. We find that there can be an absolute difference in the calculations between the two methodologies exceeding 100 nT min−1 during storm times for observatories in the sub-auroral zone, demonstrating that the choice between R and H′ can make a significant difference to any GIC estimate. We also note an observable difference between the two methodologies during quiet times when the measurements are made close to the agonic line, though this difference does not have a significant impact on the efficacy of either of the two methodologies for GIC studies. Future studies should consider carefully the choice of geomagnetic indicators for estimation of GICs. [ABSTRACT FROM AUTHOR]
Database: Energy & Power Source
Full text is not displayed to guests.
FullText Links:
  – Type: pdflink
Text:
  Availability: 1
Header DbId: enr
DbLabel: Energy & Power Source
An: 191076301
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: A comparison of methods to compute the rate of horizontal geomagnetic field variation.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Fielding%2C+Samuel A%2E%22">Fielding, Samuel A.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> sfieldin@ed.ac.uk</i><br /><searchLink fieldCode="AR" term="%22Livermore%2C+Philip W%2E%22">Livermore, Philip W.</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Beggan%2C+Ciarán D%2E%22">Beggan, Ciarán D.</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Whaler%2C+Kathryn A%2E%22">Whaler, Kathryn A.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Richardson%2C+Gemma S%2E%22">Richardson, Gemma S.</searchLink><relatesTo>3</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Annales+Geophysicae+%28ANGEO%29+%2809927689%29%22">Annales Geophysicae (ANGEO) (09927689)</searchLink>. 2025, Vol. 43 Issue 2, p687-700. 14p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Geomagnetism%22">Geomagnetism</searchLink><br />*<searchLink fieldCode="DE" term="%22Geomagnetic+variations%22">Geomagnetic variations</searchLink><br />*<searchLink fieldCode="DE" term="%22Space+environment%22">Space environment</searchLink><br />*<searchLink fieldCode="DE" term="%22Acquisition+of+data%22">Acquisition of data</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: The rate of change of the horizontal external magnetic field is often used as a proxy for space weather activity and in particular for estimating geomagnetically induced currents (GICs) in high voltage power grids. This paper compares two commonly adopted methods for computing this rate of change: (1) the difference between consecutive measurements in the magnitude of the horizontal magnetic field, H′ , and (2) the combined difference in the magnitude in the northward and eastward directions, usually denoted R. We find that there can be an absolute difference in the calculations between the two methodologies exceeding 100 nT min−1 during storm times for observatories in the sub-auroral zone, demonstrating that the choice between R and H′ can make a significant difference to any GIC estimate. We also note an observable difference between the two methodologies during quiet times when the measurements are made close to the agonic line, though this difference does not have a significant impact on the efficacy of either of the two methodologies for GIC studies. Future studies should consider carefully the choice of geomagnetic indicators for estimation of GICs. [ABSTRACT FROM AUTHOR]
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=enr&AN=191076301
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.5194/angeo-43-687-2025
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 14
        StartPage: 687
    Subjects:
      – SubjectFull: Geomagnetism
        Type: general
      – SubjectFull: Geomagnetic variations
        Type: general
      – SubjectFull: Space environment
        Type: general
      – SubjectFull: Acquisition of data
        Type: general
    Titles:
      – TitleFull: A comparison of methods to compute the rate of horizontal geomagnetic field variation.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Fielding, Samuel A.
      – PersonEntity:
          Name:
            NameFull: Livermore, Philip W.
      – PersonEntity:
          Name:
            NameFull: Beggan, Ciarán D.
      – PersonEntity:
          Name:
            NameFull: Whaler, Kathryn A.
      – PersonEntity:
          Name:
            NameFull: Richardson, Gemma S.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 07
              Text: 2025
              Type: published
              Y: 2025
          Identifiers:
            – Type: issn-print
              Value: 09927689
          Numbering:
            – Type: volume
              Value: 43
            – Type: issue
              Value: 2
          Titles:
            – TitleFull: Annales Geophysicae (ANGEO) (09927689)
              Type: main
ResultId 1