Section 2.3: Geomagnetism

The geomagnetic field is our natural shield against solar wind particles and cosmic radiation. It is mainly generated by dynamo processes in the Earth's fluid outer core. Magnetized rocks in the Earth's crust, electrical currents in ionosphere and magnetosphere in the near-Earth space and even ocean currents add contributions to the Earth's magnetic field. We use geomagnetic field observations from ground and space as well as paleomagnetic data obtained from geological archives to investigate the geomagnetic field on a broad range of time-scales. We make inferences about dynamic processes inside the Earth and in the near-Earth space environment. Our aims are to estimate the future evolution of the geomagnetic field and contribute to characterizing space weather conditions.

Working Groups

Geomagnetic field evolution

The investigation of secular variation of the geomagnetic core field on all time scales is relevant to better understand the dynamics of Earth’s core and the geodynamo process. Our reconstructions of the global geomagnetic field on historical to paleomagnetic time scales in addition inform about long-term variations in shielding against solar wind and cosmic radiation.

Geomagnetic Observatories

Globally distributed geomagnetic observatories deliver high-quality, continuous measurements of the Earth’s magnetic field. They give knowledge on changes occurring in the Earth’s core as well as in near-Earth space and they facilitate the best possible interpretation of satellite-borne magnetic measurements. Real time data are an important tool for the monitoring of acute space weather incidents. GFZ’s global network of geomagnetic observatories and associated cooperation programmes are operated from the Niemegk observatory.

Geomagnetic Variations

The Earth's magnetic field is not static but constantly changing. The variations in the geomagnetic field on time scales of minutes to days are primarily of external origin; that is, the source electric currents flow in the ionosphere (a few hundreds of kilometers from the surface) and magnetosphere (several Earth radii from the surface). Studies of those geomagnetic perturbations are, therefore, important for understanding the physical processes in the Earth's upper atmosphere and near-Earth space, which is necessary for the predictions of space weather and climate.

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