On the Ion-Acoustic Instability in the Ionospheric E-Region

Abstract

The linear theory of the ion-acoustic instability in the E-region ionospheric plasma has been studied. The instability can generate ion-acoustic waves with dispersion equation o c s k and with wavelengths of order of a metre in the region of small aspect angles y < 1 . This instability can be used for interpretation of coherent backscatter type I events. Considering the ion-acoustic instability it is also possible to explain rocket measurements during the ROSE project of waves with phase velocities smaller than the ion-acoustic velocity and dependent on frequency.