Numerical BGK-solutions of large scale electrostatic potential in auroral plasmas

Formation of large scale and large amplitude electrostatic potential along magnetic field lines due to a high‐speed plasma flow in auroral plasma is discussed. It is shown that the potential profile which is consistent with observations, i.e., which increases very slowly near the plasmasheet and abruptly near the topside ionosphere, can be obtained by introducing a population of electrons which are trapped between the magnetic mirror and the electrostatic potentials.