Interaction of magnetic clouds with the magnetospheric boundaries: bow shock and magnetopause
Résumé
Magnetic clouds are magnetic structures ejected from the Sun at higher speed than the ambient solar wind. They are generally responsible for large disturbances in the Earths environment: magnetosphere compression, triggering of geomagnetic storms. In the literature, their geo-effectiveness is studied by comparing magnetic field and plasma observations in magnetic clouds with the Dst index as a proxy for the intensity of geomagnetic storms. We focus here on an intermediate step of this process which is the interaction of the magnetic cloud with the bow shock and with the magnetopause. In order to do it, we exploit observations upstream in the solar wind (ACE, WIND,
) and observations at the crossing of the bow shock and of the magnetopause by CLUSTER. We propose to quantify the variation of characteristic field and plasma parameters of magnetic clouds across these boundaries and the motion of these boundaries.