Role of geomagnetic field in atmospheric escape from Earth

地磁场阻止了地球的大气层被太阳风吹走。但是由于太阳短波长的辐射对高层大气的部分电离，电动力可以使带电粒子沿着开放的电场线向上移动，而不受重力的影响。早在太空时代早期，人们就认识到，磁层中有相当数量的电离层离子。在本研究中，我们将研究离子在源区高度上涌的加速机制。中性粒子在热层中的作用也首次被纳入考虑范围。在我们的研究中，我们将利用CHAMP（400公里）、GRACE（500公里）和DMSP（830公里）卫星的数据。空间观测应通过适当的EISCAT雷达测量加以增强。因此，将量化不同流出区、极帽、尖点和极光区的总速率，并确定它们对地球物理条件的依赖关系。

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.