Magnetospheric Physics at Southampton

This Consolidated Grant application proposes research which will be undertaken at the University of Southampton, into the responses of two planetary systems (the magnetospheres of Earth and Jupiter) to the solar wind. Our research into Earth's magnetosphere will address questions about the fundamental process that drives the interaction between the solar wind and the Earth's magnetic field, and why it appears to occur intermittently. We will do so by exploiting data from the newly-launched NASA mission MMS in order to probe signatures of this interaction in unprecedented detail, and to determine the physical processes controlling it. The nature of this interaction depends on the orientation of the interplanetary magnetic field, which is associated with the solar wind. This orientation is highly changeable, but can be referred to as 'northward' or 'southward'. We will use satellite observations to test mechanisms that have been advocated for previously observed complex structure in the magnetosphere during periods when the interplanetary magnetic field is 'northward', and to test whether (and under what conditions) state-of-the-art simulations reproduce such activity. With respect to Jupiter's magnetosphere, we will use powerful telescopes to image Jupiter's auroras at X-ray wavelengths. These pictures of the X-ray aurora will be compared with measurements by a spacecraft called Juno which is orbiting Jupiter and is sampling its magnetic environment. The combination of the X-ray observations and Juno measurements will allow us to link the physics of what causes the X-rays to local conditions in Jupiter's magnetosphere and in the solar wind. We want to understand what physical mechanisms drive Jupiter's X-ray auroras and why they sometimes appear to flash in a periodic way.