A global model of mantle conductivity derived from 5 years of CHAMP, Ørsted, and SAC‐C magnetic data

We present a global 1‐D conductivity model which is obtained by analysis of five years (2001–2005) of simultaneous magnetic data from the three satellites Ørsted, CHAMP and SAC‐C. After removal of core and crustal fields as predicted by a recent field model we used non‐polar scalar and vector observations from the night‐side sector, and interpret the field residuals in terms of a large‐scale contribution from the magnetospheric ring current and its induced counterpart. We then derive transfer functions between internal (induced) and external expansion coefficients of the magnetic potential and provide globally‐averaged C ‐responses in the period range between 14 hours and 4 months. Since the satellite responses are probably influenced by induction in the oceans for periods shorter than a few days, we correct the data for this effect. Interpreting the corrected responses yields a 1‐D conductivity model which is rather similar to models derived from ground‐based data.