Satellite scintillation observations over the northern high latitude regions

Abstract

Observations of amplitude fluctutations of the beacon signals from two satellites were made at Thule and Narssarssuaq, Greenland, during the winter of 1968-1969. The data were used to obtain the pattern of F-layer irregularities at high latitudes during this winter season, which occurred when sunspot activity was of medium to high level. 40-MHz signals from the S-66 satellite were observed at Thule and 136-MHz signals from the ATS-3 synchronous satellite were observed at Narssarssuaq. It was found that from 64° corrected geomagnetic latitude to the pole a maximum of irregularity occurrence exists at 0530 + 02h corrected geomagnetic time and from 64° to 80° a second maximum occurs at 1700 + 02h. Using additional observations of ATS-3 at a lower latitude (53°) the morning and afternoon maxima are replaced by one maximum located after local midnight. Scintillation index averaged over 214 h does not show a significant change as a function of latitude from the pole to 73° CGL. The 24-h averaged scintillation index is higher at 60°W than over Spitzbergen (14°E), an indication of the possible existence of the 'permanent maximum' found by Penndorf (1962) in his spread-F studies. The scintillation results are in accord with the occurrence patterns of thermal and suprathermal electron irregularities and turbulent isotropic electric fields in that they all show a high level of activity over the polar cap. © 1974.