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 outer fluid core. Magnetized rocks in the Earth's crust, electrical currents in ionosphere and magnetosphere and even ocean currents add contributions to the Earth’s magnetic field. We use geomagnetic field observations and data from other plasma or atmospheric parameters obtained from ground and space instrumentation to investigate the dynamic processes inside the Earth and in the near-Earth space environment. Our aim is to better understand space weather conditions and the future evolution of the geomagnetic field.
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.
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.
The ionosphere is the ionised part of the upper atmosphere, which builds up through absorption of solar electromagnetic and particle radiation. Electric currents in the ionosphere produce signatures in the Earth’s magnetic field, both during geomagnetically quiet and disturbed times. We investigate different topics that relate to the interaction between the upper atmosphere, the magnetic field, and the solar radiation.
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.