In our study, we looked at the boundary between the Earth's magnetic field and the interplanetary magnetic field emitted by the Sun, called the magnetopause. While other studies focus on the magnetopause motion near Earth's equator, we have studied it in polar regions. The motion of the magnetopause is faster towards the Earth than towards the Sun. We also found that the occurrence of unusual magnetopause locations is due to similar solar influences in the equatorial and in the polar regions.

The Earth's magnetic field creates a magnetic bulk all around it called the magnetosphere. This bulk a priori protects us from the particles coming from the sun but sometimes undergoes violent events such as interplanetary coronal mass ejections. These cause the entry of particles into the magnetosphere, which can be harmful for satellites. In this paper, we performed a statistical study to characterize the interplanetary coronal mass ejections and their ability to disturb the magnetosphere.

We present here cases of wide banded Non Thermal Continuum (NTC) observed from the multi-point Cluster observatory. We point out that a large portion of the plasmasphere boundary layer, covering magnetic latitudes from 0 to above 30°, is radiating these radio waves. The radiation is confined inside multiple beams of small cone angles. We show how the spectral signature evolves, from integer harmonics of the electron gyrofrequency, when the observatory moves away from their sources.

Using Cluster data, we develop plasmapause Lpp models parameterized by solar wind coupling functions and geomagnetic activity indices. We show that the Lpp response to the changes in the interplanetary conditions depends on the magnetic local time. The faster plasmapause response is observed in the post-midnight sector. At low activity, Lpp exhibits the largest values on the dayside. For enhanced activity, displacements towards larger values on the evening side are identified.