Earth Planets Space, Vol. 65 (No. 11), pp. 1233-1237, 2013
Christoph Püthe and Alexey Kuvshinov
ETH Zürich, Institute of Geophysics, Sonneggstrasse 5, 8092 Zürich, Switzerland
(Received December 17, 2012; Revised July 17, 2013; Accepted July 22, 2013; Online published November 22, 2013)
We present an inversion scheme to recover the (1-D)
depth profile of mantle conductivity from satellite magnetic data,
which takes into account 3-D effects arising from the distribution
of oceans and continents. The scheme is based on an iterative
inversion of C-responses, which are estimated from time series of
the dominating external (inducing) and internal (induced) spherical
harmonic coefficients of the magnetic potential due to a
magnetospheric source. These time series will be available as a
Swarm Level-2 data product. We verify our approach by
using synthetic, but realistic time series obtained by simulating
induction due to a realistic magnetospheric source in a 3-D
``target'' conductivity model of the Earth. This model contains not
only a laterally heterogeneous layer representing oceans and
continents, but also 3-D inhomogeneities in the mantle. The
inversion for mantle conductivity is initiated with a uniform
conductivity model. Convergence is reached within a few iterations.
The recovered model agrees well with the laterally averaged target
model, although the latter comprises large jumps in conductivity.
Our 1-D inversion scheme is therefore ready to process
Key words: Electromagnetic induction, 1-D inversion, mantle conductivity, C-responses.