A phenomenological model of the enhanced airglow produced by the Department of Commerce ionospheric modification facility is presented. This model is based primarily on airglow data taken from two sites for triangulation. These data show that it is not necessary for the region in which RF power is deposited (interaction region) to be coincident with the region in which the modified airglow is emitted (excitation region). The two are coincident at altitudes below 280 ± 15 km; but, as the interaction region rises, the two may separate with the excitation region remaining at altitudes around 280 km. It is also shown that a non-Maxwellian energy distribution for electrons is generated by the transmitter. Further, using this model, we present estimates of the efficiency for converting the radio wave energy into energetic electrons. This can typically be 1%, although observations indicating efficiencies 10 to 15 times higher have been made. A variety of experimental data which are not clearly understood are also presented.