Arnaud Chulliat
Research Interests
- Geomagnetic field modeling
- Geomagnetic data analysis
- Geomagnetic observation techniques
- Earth's core magnetic field and its secular variation
- Magnetic fields of external origin (ionosphere and magnetosphere)
- Lithospheric magnetic anomalies
Current Research
NOAA-funded research
I lead the development of geomagnetic field models used by government, industry and the wider public, including the World Magnetic Model (WMM), the Enhanced Magnetic Model and the High Definition Geomagnetic Model. Our approach is to first develop research models describing the magnetic field generated by a single source, for example the Earth's core or the electrical currents in the magnetosphere, and then combine these models into composite models describing the field from several sources.
Externally funded research
I am investigating rapid geomagnetic variations of internal origin. The European Space Agency Swarm tri-satellite mission and other recent satellite missions revealed large-scale pulses in the second order time derivative of the Earth’s core magnetic field. These pulses have been occurring every three years since the mid-2000s and may lead to larger errors in predictive models such as the WMM and the International Geomagnetic Reference Field (IGRF). They also provide new observational constraints on numerical simulations of the geodynamo.
In collaboration with Institut de Physique du Globe de Paris, I am developing models of the quiet-time magnetic field variations originating in the E-layer of the ionosphere. These variations can reach several tens of nT at mid-latitudes (Sq field) and more than 100 nT under the magnetic dip-equator (equatorial electrojet). The Dedicated Ionospheric Field Inversion (DIFI) algorithm makes use of the separation in local time of two of the three Swarm satellites, a unique feature of the Swarm mission compared to previous magnetic satellite missions.
PUBLICATIONS
