Influence of suprathermal background electrons on strong auroral double layers: Vlasov-simulation parameter study

Abstract

Recent observations by the Fast Auroral SnapshoT (FAST) satellite [Andersson, Phys. Plasmas 15, 072901 (2008), this issue] suggest that characteristics of particles and waves on the high-potential side of strong double layers in Earth's auroral downward current region are influenced by properties of the suprathermal electron component. Current-driven Vlasov simulations in one spatial dimension with suprathermal electrons differing in density and temperature were performed to study their influence on double-layer evolution. A sufficiently dense and hot suprathermal population is found to stabilize strong laminar double layers over long periods while regulating their strength and velocity. Synthetic electron energy-flux spectra from simulations with different suprathermal electron populations reveal certain similarities to the corresponding FAST observations. © 2008 American Institute of Physics.