Abstract:
We modeled Cluster spacecraft observations of slow electrostatic solitary waves (SESWs) in
the Earth’s northern plasma sheet boundary layer (PSBL) region on the basis of nonlinear fluid theory and
fluid simulation. Various plasma parameters observed by the Cluster satellite at the time of the SESWs were
examined to investigate the generation process of the SESWs. The nonlinear fluid model shows the
coexistence of slow and fast ion acoustic waves and the presence of electron acoustic waves in the PSBL
region. The fluid simulations, performed to examine the evolution of these waves in the PSBL region,
showed the presence of an extra mode along with the waves supported by the nonlinear fluid theory.
This extra mode is identified as the Buneman mode, which is generated by relative drifts of ions and
electrons. A detailed investigation of the characteristics of the SESWs reveals that the SESWs are slow ion
acoustic solitary waves.
