Terrestrial foreshock physics: correlating space-based observations with numerical simulations

The upstream region of quasi-parallel terrestrial bow shocks is among the most complex plasma systems. Here the lack of collisions requires multi-scale collective dynamics to mediate energy dissipation and isotropy. The principles underpinning this behaviour represent the most generic plasma processes: strong turbulence, Fermi acceleration, shock reformation and number of plasma instabilities. A key feature of the terrestrial foreshock is the presence of the energetic ion population, which forms an ion beam. These ions are reflected from the shock, stream sunwards, and can become unstable to small perturbations. A recent study performed at Warwick revealed a temperature increase of the bulk plasma, which was correlated with the level of the anisotropy in particle velocity distribution, with respect to the magnetic field direction. The working hypothesis is that the nonlinear coupling between the reflected ion population and the bulk plasma leads to a secondary instability of the fire hose or proton cyclotron type. This project will combine observations from Cluster spacecraft and numerical simulations to test this hypothesis.

Research at Warwick University’s Centre for Fusion, Space and Astrophysics (CFSA) focuses on plasma physics applied to the grand challenges of fusion energy, space physics, solar physics, and astrophysics. Our work spans fundamental theory, observation, and the analysis of experimental data, combined with high performance computing. For more details of the CFSA see http://go.warwick.ac.uk/cfsa

The project is available for 3.5 years with a start date of 2 October 2017.

If interested in the first instance contact Dr Bogdan Hnat, Physics Department, University of Warwick ([Email Address Removed])