Abstract:

We currently have the capability of studying the Sun-Earth connection from a number of space missions, which cover remote sensing, and in situ measurements. While these provide us with a crucial insight into the effects on the Earth's environment of plasma from the Sun they are made in the main by instruments on different spacecraft that provide only a single view of an event or a single sample location. We describe two examples of ejections of mass from the Sun. The first is a small source region. In this case the orientation and helicity of the magnetic cloud matched that of the pre-eruption solar source. In the second example the source is a large solar flare from a complex active region in the declining phase of the solar cycle. We made use of the multi-spacecraft datasets from SOHO, TRACE, Cluster, ACE, WIND and GOES to track the coronal mass ejection. In this case also, we find that the magnetic field orientations in the clouds have changed little from their solar coronal configurations. We discuss what is currently lacking in our knowledge and how the imminient Solar-B, STEREO and Solar Dynamics Observatory Missions will improve this. We then describe our expectations of the future encounter mission, Solar Orbiter, which will give us our first opportunity to link in-situ and remote sensing observations from a single platform close to the Sun. Finally we will look further into the future, and describe a multi-satellite mission concept that could make a crucial leap forward in our understanding of the Sun-Earth system.