Generation of whistler waves by continuous HF heating

9 Broadband whistler waves in the frequency range 7-10 kHz and 15-19 kHz, generated by 10 F-region CW HF ionospheric heating in the absence of electrojet currents, were detected 11 by the DEMETER satellite overflying the HAARP transmitter during HAARP/BRIOCHE 12 campaigns. The whistler waves are in a frequency range corresponding to the F-region 13 Lower-Hybrid (LH) frequency and its harmonic generated by mode conversion of LH waves 14 that were parametrically excited by HF-pump-plasma interaction at the upper hybrid layer. 15 The paper discusses the basic physics and presents a model that conjectures: (i) The whistler 16 wave observed at the LH frequency is due to the interaction of the LH waves with meter17 scale field aligned striations; (ii) The whistler wave at twice the LH frequency is due to the 18 interaction of two counter-propagating LH waves. The model is supported by numerical 19 simulations that show good agreement with the observations. 20