Role of geomagnetic field in atmospheric escape from Earth

• Applicant: Professor Dr. Hermann Lühr
• Subject Area: Atmospheric Science
• Term: from 2010 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 169031908

The geomagnetic field prevents the Earth from having its atmosphere swept away by the solar wind. But due to the partial ionization of the upper atmosphere by the sun’s short-wavelength radiation electrodynamic forces can move the charged particles upward, against gravity, along open field lines. Already in the early space age it was recognized that considerable amounts of ionospheric ions populate the magnetosphere. In this study we will investigate the acceleration mechanisms of the up-welling ions at source regions altitude. For the first time the role of the neutral particles in the thermosphere are also included in the considerations. For our studies we will make use of data from the satellites CHAMP (400km), GRACE (500km) and DMSP (830km). The space observations shall be augmented by suitable EISCAT radar measurements. As a result the total rates of the different out-flow regions, polar cap, cusp, and auroral region will be quantified and their dependence on geophysical conditions determined.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1488: Planetary Magnetism (PlanetMag)
• Participating Person: Professor Dr. Michael Weber