Nonlinear Disturbances in the Ionospheric E Region under the Action of Internal Gravity Waves

We consider the influence of harmonics generated by an internal gravity wave (IGW) on the formation of nonlinear disturbances in the ionospheric E region. It is shown that the response of the lower ionosphere to the IGW propagation should be less efficient than the action of the IGW on the ionospheric F region. Nevertheless, if there are some thin layers (e.g., sporadic E layers) in the lower ionosphere, the response can be amplified; its amplitude is determined by the sharpness of the density gradient as compared with the characteristic scale of the atmosphere.