Space plasma disturbances caused by NAU-launched whistler waves

Radio signals from Naval (NAU) transmitter in Puerto Rico can interact effectively with naturally occurring or HF heater wave-induced large-scale ionospheric irregularities, allowing them to propagate as whistler-modes in the ionosphere and to the inner radiation belts. NAU-generated whistler-modes have intensities sufficient to parametrically excite lower hybrid waves and ten-meter and meter-scale ionospheric irregularities over Arecibo. Subsequent heating of electrons and ions by the lower hybrid waves yield a sequence of ionospheric plasma effects such as airglow, short-scale density depletion and plasma line enhancements in a range of altitudes which far exceed that caused by the HF heater. Furthermore, they can interact with trapped energetic electrons in inner radiation belts at L=1.35 and trigger precipitation of electrons into the lower ionosphere. We suggest that disturbances in the ionosphere above NAU caused by whistler-mode signals can significantly affect heater-induced perturbations and partially explain unique results obtained at other heater sites.