Quantifying the Importance of an L5 Magnetograph

Currently the Sun may only be observed along the line joining the Sun and Earth. This viewpoint called the L1 viewpoint means that we have limited observations of active region that emerge on the Sun and due to this limited data for predicting when eruptions and disruptive Space Weather will occur. To counter this a new space mission has been proposed to place a satellite at the L5 point which lies 60o behind the Earth. This satellite will provide advance warning of Space Weather producing phenomena on the Sun. To consider how a magnetograph placed at the L5 point will improve Space Weather predictions a series of 3D non-potential numerical simulations of the Sun's global magnetic field over two , eleven year solar cycles will be carried out. By using a carefully constrained data set called the reference Sun simulation, we will determine how more accurate the simulations become when data from both L1 + L5 is included compared to just L1. In addition to this the improvements from considering a second satellite placed at L4 (60o in front of Earth) will be determined. The improvements will be quantified by considering (a) the accuracy of the surface flux, (b) the total and free magnetic energy, (c) the open flux and finally (d) the time of formation and eruption of magnetic flux ropes.