摘要：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 Swarm data. Key words Electromagnetic induction 1-D inversion mantle conductivity C -responses.
