Multispacecraft observations of Coronal Mass Ejections

The Sun-Earth environment is strongly influenced by the coupling level between the Earth magnetosphere and the interplanetary magnetic field. The latter is closely related to the solar wind, a flux of plasma continuously flowing from the Sun and propagating in the interplanetary space medium. This plasma is constituted by electrons, protons and heavier particles, and propagates with a speed of 400-800 km/s, reaching Earth in 2.4-4.6 days. A sudden increase of the solar wind's speed is achieved by two types of phenomena: flares and Coronal Mass Ejections (CMEs). In this context, this thesis concerns the study of the physical processes that lie at the base of the CME formation and of their effects on the Sun-Earth environment. Such an investigation can be done utilizing data taken from satellites that study solar wind, interplanetary magnetic field, flares and CMEs.