Current carrying properties of double layers and low frequency auroral fluctuations

Numerical simulations showed recurring interruption and recovery of electron and ion currents through double layers. The time period τ of the recurring phenomena is governed by the ion dynamics; for ions with a drift Vi entering the simulation plasma such that Vi≲Vti, the ion thermal speed, τ is governed by the ion transit time from the location of ion injection to the location of the double layer. On the other hand, when Vi>Vti ion‐acoustic modes also appear in the electron‐ and ion‐current fluctuations. The electron current fluctuations are governed by the ion current through the Langmuir criterion. It is suggested that some low frequency auroral fluctuations could possibly be explained by current fluctuations through double layers.