Summary
New satellite data have led to increased resolution models of the geomagnetic secular variation (SV). Simple plots of the spectra of these models suggest an unphysical source depth above the core-mantle boundary (CMB). By taking a ratio of the main field and SV spectra, we argue that this result comes from the chosen spectral definition. The models are consistent with a CMB source for SV.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Bloxham J and Jackson A (1992) Time-dependent mapping of the magnetic field at the core-mantle boundary. J Geophys Res 97: 19,537–19,563.
Cain JC, Wang Z, Schmitz DR, and Meyer J (1989) The geomagnetic spectrum for 1980 and core-crustal separation. Geophys J 97: 443–447.
De Santis A, Barraclough DR, and Tozzi R. (2003) Spatial and temporal spectra of the geomagnetic field and their scaling properties. Phys Earth Planet Int 135:125–134.
Holme R. and Bloxham J (1996) The treatment of attitude errors in satellite geomagnetic data. Phys Earth Planet Int 98: 221–233.
Lowes FJ (1974) Spatial power spectrum of the main geomagnetic field, and extrapolation to the core. Geophys J R Astron Soc 36: 717–730.
McLeod MG (1985) Statistical theory of the geomagnetic field and its secular variation. EOS Trans. AGU 66(46): 878.
McLeod MG (1996) Spatial and temporal power spectra of the geomagnetic field. J Geophys Res 101: 2745–2763.
Olsen N (2002) A model of the geomagnetic field and its secular variation for epoch 2000 estimated from Ørsted data. Geophys J Int 149: 454–462.
Voorhies CV (2004) Narrow scale flow and a weak field by the top of Earth's core: evidence from Ørsted, Magsat and secular variation. J Geophys Res, in press.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2005 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Holme, R., Olsen, N. (2005). The Spectrum of the Magnetic Secular Variation. In: Reigber, C., Lühr, H., Schwintzer, P., Wickert, J. (eds) Earth Observation with CHAMP. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-26800-6_52
Download citation
DOI: https://doi.org/10.1007/3-540-26800-6_52
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-22804-2
Online ISBN: 978-3-540-26800-0
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)