Lidar returns from the upper atmosphere and possible causes of their generation

Abstract

New experimental data which confirm episodic occurrence of the correlation of light backscattering lidar signals from a 150–300 km altitude region with the plasma content in the nighttime F 2 layer of the ionosphere are presented. Analysis results of lidar observation data for 2008–2014 are given. A conclusion is drawn that these correlations occur when additional sources for ionosphere ionization appear. A hypothesis is discussed that the resonance scattering by excited atomic nitrogen ions is a possible cause of generation of these signals.