摘要

The maximum usable frequency (MUF(3000) F2) decile factors obtained from observations at five stations located in the Arctic region: Resolute (74.75 degrees N, 265.10 degrees E), Dikson (73.50 degrees N, 80.40 degrees E), Norilsk (69.40 degrees N, 88.10 degrees E), Loparskaya (68.00 degrees N, 33.00 degrees E), and Sodankyla (67.40 degrees N, 26.60 degrees E) have been compared with the International Telecommunication Union (ITU-R) estimates over three solar cycles (1961-2013). The summer MUF(3000) F2 variability has been found to lie in the range of +/- 0.2, whereas limits for equinox and winter seasons are +/- 0.3 and +/- 0.5, respectively. This observation seems to directly translate into high differences between the measurement-derived and ITU-R decile values in winter and the smaller values for summer. These results illustrate that the high latitude ionosphere, and thus the MUF, is highly variable in winter, followed by the equinox, and experiences a low variability in summer.

  • 出版日期2016-8