Fig. 4: Ionospheric profiles.
From: Controlled beat-wave Brillouin scattering in the ionosphere
a Ionospheric density profile, b ray paths in the magnetic meridian (\(x\)-\(z\)) plane of O and X mode waves of frequency 6.3 MHz injected vertically, c the profiles of the estimated electron temperatures during X and O mode heating (the ion temperature is \({T}_{{{{{{\rm{i}}}}}}}=1000{{{{{\rm{K}}}}}}\)), d the estimated resonant ion-acoustic (IA) wavenumber \({k}_{{{{{{\rm{IA}}}}}}}=2{k}_{{{{{{\rm{EM}}}}}},z}\), e the resonant IA wave frequency \({f}_{{{{{{\rm{IA}}}}}}}={\omega }_{{{{{{\rm{R}}}}}}}/2\pi\), and f the relative ion Landau damping rate \(\left|{\omega }_{{{{{{\rm{I}}}}}}}/{\omega }_{{{{{{\rm{R}}}}}}}\right|\).
