Resolution of direction of oceanic magnetic lineations by the sixth-generation lithospheric magnetic field model from CHAMP satellite magnetic measurements

The CHAMP satellite continues to provide highly accurate magnetic field measurements from decreasing orbital altitudes (< 350 km) at solar minimum conditions. Using the latest 4 years (2004 -2007) of readings from the CHAMP fluxgate magnetometer, including an improved scalar data product, we have estimated the lithospheric magnetic field to spherical harmonic degree 120, corresponding to 333 km wavelength resolution. The data were found to be sensitive to crustal field variations up to degree 150 (down to 266 km wavelength), but a clean separation of the lithospheric signal from ionospheric and magnetospheric noise sources was achieved only to degree 120. This new MF6 model is the first satellite-based magnetic model to resolve the direction of oceanic magnetic lineations, revealing the age structure of oceanic crust.