Modelling the quiet-time geomagnetic daily variations using observatory data
Hamilton, Brian; Macmillan, Susan. 2008 Modelling the quiet-time geomagnetic daily variations using observatory data. [Poster] In: GEOSPACE Consortium Meeting ( July 2008), Abingdon, 3-4 July 2008. (Unpublished)Before downloading, please read NORA policies.
We present on-going work towards building a global model of the quiet-time geomagnetic daily variation using bservatory data. We select hourly mean data during June 2006 (solar minimum). We fit Fourier series in time, with a fundamental period of 24 hours, to the data at each observatory. We then use global spherical harmonic expansions to separate the daily variation signal, as characterised by the Fourier coefficients in time, into external and induced internal contributions. The models are assessed by comparison with the input data and with Campbell’s Sq model. The robustness of the separation of the field into external and induced internal sources is discussed.
|Item Type:||Conference or Workshop Item (Poster)|
|Programmes:||BGS Programmes > Seismology and Geomagnetism|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||26 Oct 2012 08:19|
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