Simultaneous excitation of broadband electrostatic noise and electron cyclotron waves in the plasma sheet

Electron cyclotron harmonics and broadband electrostatic noise (BEN) are often observed in the Earth's outer plasma sheet. While it is well known that ion beams in the plasma sheet boundary layer can generate BEN, new two dimensional electrostatic simulations show that field‐aligned ion beams with a small perpendicular ring distribution can drive not only BEN, but also electron cyclotron harmonic (ECH) waves simultaneously. Simulation results are presented here using detailed diagnostics of wave properties, including dispersion relations of all wave modes.