Nonlinear structuring and southward shift of a strongly heated region in ionospheric modification

Abstract

The theory of self-focusing on striations for the powerful radio wave beam propagating in the northern or midlatitude ionosphere is developed. It is demonstrated that focusing lead to formation of a large scale nonlinear structure aligned magnetic field. It consists of a number of closely packed solitons — bunches of striations. The anomalous absorption of a pump wave trapped in solitons lead to the strong ohmic heating of electrons in the focused region. The theory is in a good agreement with the results of recent observations of optic emission and temperature enhancement in northern ionospheric modification experiments.