Séminaire ISTerre

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Accounting for correlated errors in geomagnetic field modelling

mardi 5 mars 2024 - 11h15

Clemens Kloss - DTU, Department of Space Research and Technology
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Modern geomagnetic field models can successfully represent many details of the observed large-scale field and its slow time changes. However, their uncertainty estimates are typically too small because, among other reasons, data errors are usually assumed to be temporally uncorrelated and are often specified independent of position during the model estimation. The lack of realistic model uncertainties thus hinders the use of these models in applications such as assimilation into numerical Geodynamo simulations. Here, I present preliminary results from studying the spatiotemporal statistics of the vector residuals between magnetic observations from the Swarm satellites and predictions from the CHAOS-7 field model. I compute sample covariances from the vector residuals as a function of time lag for different quasi-dipole latitudes and magnetic local times. By fitting simple spatiotemporal covariance functions to the quiet-time night-side features in these empirical covariances, I explore ways to build realistic data error matrices to be included in geomagnetic field modeling.

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Equipe organisatrice : Géodynamo

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères