VLF electromagnetic field structures in ionosphere disturbed by Sura RF heating facility

Abstract

Observation of spatial VLF field structures in an artificially disturbed ionosphere is reported. The disturbed area with horizontal sizes ∼50 km in a quiet middle-latitude ionosphere was produced by the powerful RF Sura heating facility (561N, 461E). Measurements were carried out onboard the DEMETER satellite while passing the disturbed area at height ∼700 km. Spectra broadening (Δ f < ± 1 kHz) and considerable (up to 30 dB) increase of signal intensity of VLF transmitters' signals were observed. The VLF field and electron density irregularities have similar spatial structure. The characteristics of the VLF field in disturbed by RF heating area are analyzed. Copyright 2010 by the American Geophysical Union.