Julien Aubert, CNRS, IPG Paris

I am a CNRS senior researcher working at the Institut de Physique du Globe de Paris (IPGP), within the Geological Fluid Dynamics team. 

I am interested in the interpretation of the geomagnetic signal emanating from Earth’s liquid outer core. Over a broad range of space and time scales, this signal is a powerful probe for investigating the structure, dynamics and geological history of our planet. Understanding the geodynamo is an outstanding fundamental challenge of Physical Sciences as well as Earth Sciences. 

To this end I develop and use direct numerical computer simulations of the dynamo process, as well as data assimilation algorithms aiming at forecasting the future evolution of the geomagnetic field. This has important societal impacts as the geomagnetic field interacts with life on Earth and with human technological activities.


The goal of the 4D-Earth-Swarm project, supported by the European Space Agency, is to improve our understanding of the rapid (interannual) changes in the geomagnetic field, as recorded by the three satellites of the Swarm mission of ESA - as well as earlier satellite missions and ground-based observatories. The work also involves input from state-of-the-art numerical simulations of the geodynamo. Full details on the project can be found after this link.

As a partner in the 4D-Earth-Swarm projects, IPGP delivers an advanced geodynamo simulation helping to analyse the satellite geomagnetic record. The deliverables and papers from this work can be found in the 4DEarth section of this website.


Papers from the 13th generation of the International Geomagnetic Reference Field (IGRF) are now published online.

Below are the references and links to the summary paper

Alken, P et al.:  International Geomagnetic Reference Field: the thirteenth generation, Earth Planets Space 73, 49, 2021. doi: 10.1186/s40623-020-01288-x

the evaluation technical note

Alken, P. et al.: Evaluation of candidate models for the 13th generation International Geomagnetic Reference Field, Earth Planets Space 73, 48, 2021. doi: 10.1186/s40623-020-01281-4

and the IPGP secular variation candidate model which uses the latest implementation of inverse geodynamo modelling:

Fournier, A., Aubert, J., Lesur, V., Ropp, G.:  A secular variation candidate model for IGRF-13 based on Swarm data and ensemble inverse geodynamo modelling, Earth Planets Space 73, 43, 2021. doi: 10.1186/s40623-020-01309-9


The exploration of the path in parameter space to Earth’s core continues, and the next stop is at 71 percent along the road. 246 million simulation time steps and 15 million CPU hours spent over the course of two years were necessary to complete this new model, where we explore the coexistence and interaction of slow convection and rapid hydromagnetic waves in Earth’s core.

This paper has been published in Geophysical Journal International.

Aubert, J., Gillet, N.: The interplay of fast waves and slow convection in geodynamo simulations nearing Earth's core conditions, in press, Geophys. J. Int., 2021, doi: 10.1093/gji/ggab054