资源环境科技发展态势分析平台

Detailed mapping of Earth’s magnetic field brings key constraints on the composition, dynamics and history of the crust. Satellite and near-surface measurements detect different lengthscales and are complementary. Here, we build a model, selecting and processing magnetic field measurements from the German CHAMP and ESA Swarm satellites, which we merge with near-surface scalar anomaly data. We follow a regional approach for modelling the magnetic field measurements and next transform the series of regional models into a unique set of spherical harmonic Gauss coefficients. This produces the first global model to spherical harmonic degree 1050 derived by inversion of all available measurements. The new model agrees with previous satellite based models at large wavelengths and fits the CHAMP and Swarm satellite data down to expected noise levels. Further assessement in the geographical and spectral domains shows the model to be stable when downward continued to the Earth's surface.