Time-domain, spectral finite-element approach to transient 2-D geomagnetic induction in a spherical heterogeneous Earth Academic Article

abstract

• A time-domain, spectral finite-element approach is presented for computing the electromagnetic induction response of a 2-D heterogeneous conducting sphere to transient external current excitation. This method is appropriate for determining the induced spatiotemporal electromagnetic signature at satellite altitudes associated with the upper and mid-mantle conductivity heterogeneities. The new approach is based on an existing frequency-domain 2-D spectral finite-element technique modified by the implementation of a time-stepping algorithm. To validate the time-domain approach and the associated numerical code, transient responses of concentrically and eccentrically nested spheres to ring-current excitations are computed using the inverse Fourier transform of analytical and semi-analytical, frequency-domain solutions. We show that the time-domain approach is particularly appropriate when the external current excitation has a transient feature. Compared with the frequency-domain method, it may significantly reduce the computation time while maintaining the time resolution.

authors

• Everett, Mark

published proceedings

• GEOPHYSICAL JOURNAL INTERNATIONAL

author list (cited authors)

• Martinec, Z., Everett, M. E., & Velimsky, J.

citation count

• 16

complete list of authors

• Martinec, Z||Everett, ME||Velimsky, J

publication date

• October 2003

publisher

• Oxford University Press (OUP)  Publisher

published in

• Geophysical Journal International  Journal

keywords

• Electrical Conductivity
• Electromagnetic Induction
• Explicit Time Differencing
• Linear Finite Elements
• Spherical Harmonics

Digital Object Identifier (DOI)

• 10.1046/j.1365-246X.2003.01964.x

start page

• 33

end page

• 43

volume

• 155

issue

• 1

URL

• http%3A%2F%2Fdx.doi.org%2F10.1046%2Fj.1365-246x.2003.01964.x