首页    期刊浏览 2025年02月20日 星期四
登录注册

文章基本信息

  • 标题:On the possibility of extending the IGRF predictive secular variation model to a higher SH degree
  • 本地全文:下载
  • 作者:Luís Silva ; Stefan Maus ; Gauthier Hulot
  • 期刊名称:Earth, Planets and Space
  • 电子版ISSN:1880-5981
  • 出版年度:2010
  • 卷号:62
  • 期号:10
  • 页码:815-820
  • DOI:10.5047/eps.2010.07.005
  • 出版社:Springer Verlag
  • 摘要:The International Geomagnetic Reference Field (IGRF) is an internationally agreed global spherical harmonic model of the Earth’s magnetic field of internal origin.It is currently computed every five years in the form of a model describing this field up to degree 13 at a reference epoch, plus a secular variation model up to degree 8, best estimating the linear evolution of this field over the following five years.Such a simple description of the field evolution is thought to provide a good enough prediction of the field, both for navigational and internationally agreed reference purposes (the very purpose of IGRF models).In particular, it assumes that any change in the field described by spherical harmonic degrees between 9 and 13 may be neglected over five years, given the uncertainties already involved in the determination of all other coefficients, and the practical accuracy needed for most IGRF applications.Recent progress in global field modelling based on increasingly accurate and numerous satellite data however show that all field coefficients can now be computed with much higher accuracy than possible in the past, and that higher degree secular variation coefficients could therefore also be considered for inclusion in IGRF models.The present short note intends to investigate the potential benefit of extending the IGRF predictive secular variation model to degrees higher than 8, given our current knowledge of the way the field behaves over time periods of five years.
  • 关键词:Geomagnetism ;field modelling ;reference field ;secular variation
国家哲学社会科学文献中心版权所有