Large-scale structure of Earth's magnetosphere

The Earth's magnetic field forms a cavity in the solar wind called the magnetosphere; the interaction between the solar wind and the magnetosphere is ultimately responsible for the dynamics of near-Earth space, including variations in the intensity of the radiation belts and the most spectacular displays of the aurora (the northern and southern lights). The nature of these interactions depends on the orientation of the magnetic field associated with the solar wind (the interplanetary magnetic field, or IMF); a "southward" orientation of the IMF (opposite to the Earth's magnetic field) is preferential for many magnetospheric processes, but the IMF direction is highly variable, and the dynamics of the magnetosphere under northward IMF conditions are, in comparison, poorly understood. Study of the large-scale structure and dynamics of the magnetosphere is highly timely, given the upcoming joint European/Chinese mission SMILE (Solar wind Magnetosphere Ionospheric Link Explorer, expected to launch in 2025). This project will use a combination of space-based observations (e.g. in situ plasma observations from the Cluster, THEMIS and ARTEMIS missions) and ground-based observations (from ionospheric radars such as the SuperDARN consortium and the European Incoherent Scatter radar, EISCAT) to investigate the large-scale structure of the magnetosphere. Possible topics include: the spatial extent of the magnetospheric "cusps", and how that may depend on solar wind conditions; magnetospheric structure associated with northward IMF conditions; and/or the nature of time-varying magnetic reconnection, which couples the solar wind to the magnetosphere.