A Day-time Maximum of Oblique Auroral Reflexions observed in the Auroral Zone

Abstract

ALMOST all investigations of high-frequency and very high-frequency reflexions from aurora made in or near the auroral zone have given diurnal variation curves with one main maximum near local midnight^1–3. An exception is the recent observations by Presnell et al. ⁴ at 216 Mc./s., made at College, which—for diffuse echoes only—has given two maxima, one in the morning and one in the afternoon with the peak between 1700 and 1900 L.T. Observers at lower latitudes have usually found two maxima in the night^5–8.