Enhanced O I 6300-A regions produced by the Platteville ionospheric modification experiment

The 6300-A intensity enhancements produced by absorption of radio frequency energy by the F region electrons (ionospheric modification) over Platteville, Colorado, have been mapped every 15 s over a 30degree x 30degree sector of the night sky by using a spatial scanning filter photometer. Both predicted and apparently anomalous motions of the 6300-A enhanced intensity regions are observed. In some cases, localized reductions below ambient 6300-A nightglow intensities have been observed following termination of the radio frequency heating. The observations are analyzed in terms of possible effects of electron motion along the magnetic field, enhanced ambipolar diffusion, F region neutral winds, etc