On a relation between the spatial spectra of electron density and electric field fluctuations in the presence of gradient-drift instability in the ionosphere

Connection between spatial spectra of electric field fluctuation capacity and electron concentration in E and F regions of ionosphere in case of gradient-drift instability is considered. Conditions are formulated under which these spectra are identical. Thus at the E region altitude the latter fact should take place under ue02>>vTi2(kli)2,where ue0 is the electron regular drift rate, vTi is the ion thermal rate, k is the wave number for electrostatic disturbance, li is the ion free path