In the past there has been great interest in monitoring enhanced 557.7 nm O
(S-1) emissions from the thermosphere in connection with high-power, high-f
requency (HF) radio wave modification of the F region ionosphere. These emi
ssions are considered to be evidence that the HF-modified electron distribu
tion function is non-Maxwellian because a significant flux of similar to 5-
6 eV electrons is required to produce the airglow. The suprathermal tail is
believed to develop as a result of nonlinear plasma processes. Past F regi
on observations of 557.7 nm airglow at Arecibo Observatory, Puerto Rico hav
e yielded only a few Rayleighs of enhanced emissions. Recently, airglow enh
ancements were monitored in sporadic E above Arecibo. Surprisingly, these e
xperiments yielded similar to 55 Rayleighs of enhanced 557.7 nm airglow and
the first observations of emissions from the N-2 first positive molecular
bands. The observations imply that a large flux of energetic (5-10 eV) elec
trons is generated as part of the wave-plasma interaction in sporadic E.