Speaker
Description
The correlation between linear and nonlinear ion acoustic waves (IAWs); i.e. solitary waves, observed in the vicinity to the Sun is still an open question. These electrostatic structures have a high electric field and are regularly spaced (Mozer et al. 2021; Graham et al. 2021). We study the onset of the ion acoustic instability in a parameter regime compatible with these observations. In the presence of two resonant counter-streaming ion populations, ion-acoustic instabilities may develop (Gary & Omidi 1987). We check with kinetic linear theory analysis that the system is unstable due to IA instability. We then verify our results with 1D VlasovPoisson simulations. Our main results are the following: 1) we do observe ion acoustic instability in a regime
compatible with the Mozer and Graham observations 2) we observe the production of a chain of ion holes which produce, in the frame of the core distribution, signatures compatible with the high-frequency bursts
recorded in observations.
