Role of the geomagnetic field in atmospheric escape from Earth

Atmospheric Escape

The geomagnetic field prevents the Earth from having its atmosphere swept away by the solarwind. But due to the partial ionization of the upper atmosphere by the sun’s short-wavelengthradiation electrodynamic forces can move the charged particles upward, against gravity, alongopen field lines. Recent observations have shown that the bulk of the escaped ion have very lowenergy. This result implies that they are coming from deep inside the thermosphere. In this studywe will investigate the acceleration mechanisms of the up-welling ions without heating them toomuch. For achieving that the thermospheric dynamics is included in the considerations. We willmake use of data from satellites like CHAMP (400km), GRACE (500km) and DMSP (830km) andlater include observations from ESA’s constellation mission SWARM. Measurements in themagnetosphere (e.g. by POLAR, Cluster) shall augmented the observations in the source region.As a result the total rates from the different out-flow regions, polar cap, cusp, and auroral regionwill be quantified and their dependence on geophysical conditions determined.

This project is part of the DFG priority programme SPP 1488, "Planetary Magnetism".

Contact

Mr. Prof. Dr. Hermann Lühr
Geomagnetism

Behlertstraße 3a
Building K 3, room 016
14467 Potsdam
tel. +49 331 288-1735