Instability Caused by an Inhomogeneous Energy Density Distribution as a Possible Source of Electrostatic Broadband Noise

Plasma instability caused by an inhomogeneous energy density distribution is considered. It is shown that this instability can lead to the excitation of electrostatic ion-cyclotron and oblique ion-acoustic waves, generated in the presence of an inhomogeneous transverse electric field and a shear in the parallel drift velocity of the plasma particles. The considered physical mechanisms of the instability generation in plasma can serve as possible sources of broadband electrostatic turbulence in the auroral ionosphere.