A persistent subauroral scintillation enhancement observed in Alaska

Abstract

The most persistent, identifiable feature on intensity and phase scintillation records of coherent beacon signals recorded near Fairbanks, Alaska during several months in 1976 is a narrow region of enhanced scintillation to the south of the station. On high‐elevation passes the feature occurs near the magnetic zenith, suggesting that it could be a geometric enhancement produced by field‐aligned irregularities. The feature also occurs, however, on medium and low‐elevation passes when the minimum off‐field angle is several tens of degrees. The observations, therefore, represent evidence for either (1) a hitherto unrecognized irregularity enhancement or layer thickening in the subauroral ionosphere, or (2) longitudinally extended irregularity sheets.