Flow in the magnetosheath: the legacy of John Spreiter

We review the evolution of our understanding of the processes governing the flow in the magnetosheath from the earliest model of Spreiter to the current outstanding issues. The earlier models can be characterized as single-wave-mode monotonic processes, namely the gasdynamic model for the magnetosonic mode and the plasma depletion models for slow modes. In the 1990s, a slow shock was identified in the magnetosheath from observations and theoretical models were proposed to describe the processes. We are now in an exciting period of reconstructing both our theoretical and observational understanding of the magnetosheath processes.