Geomagnetic Reference Field coefficient values for 1985 contain specific precision standards.
the verdict
INSUFFICIENT LEANING
refutedsupported
the weight of evidence
2 sources for · 0 against
Retrieved records acknowledge the existence of the 1985 IGRF revision and general model uncertainties across broad multi-decadal intervals, but do not contain specific data establishing particular precision standards for the 1985 coefficient values.
Abstract IAGA Division I, Working Group 1 deals with the topic "Analysis of the Main Field and Secular Variations." One of the more important functions of the working group is the periodic revision of the International Geomagnetic Reference Field (IGRF). The thirteen members of the working group have professional interests covering a broad spectrum of geomagnetic science, including the theory and practice of geomagnetic analysis and modeling, the theory of the origin of the magnetic fields of the Earth and other bodies, the theory of geomagnetic secular variation, the application of field models in magnetic survey data processing, and geomagnetic charting.
International Geomagnetic Reference Field revision 1985, International Association of Geomagnetism and Aeronomy, Division I, Working Group 1 International Geomagnetic Reference Field revision 1985, International Association of Geomagnetism and Aeronomy, Division I, Working Group 1 Publication Geophysics Record type Journal article Published 1 April 1986 Authors Norman W. Peddie DOI https://doi.org/10.1190/1.1442144 The publisher of this work supports multiple resolution .
The work is available from the following locations: geoscienceworld.org geoscienceworld.org debug {'doi': '10.1190/1.1442144', 'member_id': '186', 'member': 'Society of Exploration Geophysicists', 'container-title': 'Geophysics', 'primary-resource': 'https://pubs.geoscienceworld.org/geophysics/article/51/4/1020/68728/International-Geomagnetic-Reference-Field-revision', 'tld': 'geoscienceworld.org', 'clearbit-logo': '/static/no_logo.svg', 'coaccess': [], 'multiple-resolution': [{'url': 'http://geophysics.geoscienceworld.org/cgi/doi/10.1190/1.1442144', 'tld': 'geoscienceworld.org', 'clearbit-logo': '/static/no_logo.svg'}], 'type': 'JOURNAL ARTICLE', 'published_date': '1 April 1986', 'publication': 'Geophysics', 'title': 'International Geomagnetic Reference Field revision 1985, International Association of Geomagnetism and Aeronomy, Division I, Working Group 1', 'name': None, 'id': None, 'location': None, 'display_doi': 'https://doi.org/10.1190/1.1442144', 'grant_info': None, 'grant_info_funders': None, 'grant_info_funder_ids': '', 'grant_info_type': None, 'multiple_lead_investigators': [], 'multiple_co_lead_investigators': [], 'multiple_investigators': [], 'finances': [], 'project_description': None, 'award_amount': None, 'award_start': None, 'funding_scheme': None, 'internal_award_number': None, 'editors': None, 'authors': 'Norman W.
<p>The International Geomagnetic Reference Field (IGRF) is a multi-institute model of the Earth’s magnetic field, compactly described by sets of up to 195 spherical harmonic (Gauss) coefficients to degree and order 13, which allows the continuous evaluation of the field at any location and time on or above the surface. It is developed from satellite and ground-based magnetometer data and describes the large-scale variation of the magnetic field in space and time under quiet conditions. While much effort has been made on improving the forecast of the secular variation of the field over the five-year intervals between release and renewal, less emphasis has been placed on understanding the spatial errors from a user point of view. We estimate the large-scale time-invariant spatial uncertainty of the IGRF based on the globally averaged misfit of the model to semi-independent ground-based measurements at repeat stations and observatories between 1980 and 2021. As the ground measurements are reduced to quiet-time values, the external field is minimized. We find the 68.3% confidence interval is 87 nT in the North (X) component, 73 nT in the East (Y) component and 114 nT in Vertical (Z) component. Due to the Laplacian distribution of the residuals, the standard deviations are larger at 144, 136 and 293 nT, respectively.</p>
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