A Spherical Harmonic Model of Earth's Lithospheric Magnetic Field up to Degree 1050
Résumé
Detailed mapping of the Earth's magnetic field rings key constraints on the composition,
dynamics, and history of the crust. Satellite and ear-surface measurements detect different length scales
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 modeling he magnetic field measurements and next transform
the series of regional models into a unique set of spherical harmonic (SH) Gauss coefficients. This
produces the first global model to SH 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 assessment in the geographical and spectral domains shows the model to be stable when downward continued to the Earth's surface.
Domaines
Géophysique [physics.geo-ph]
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