The winter anomaly as seen in the propagation of low frequency 40 kHz radio waves
Abstract
An analysis of propagation data for LF 40 kHz radio waves shows that the field strength of the sky wave is enhanced during day-time on winter anomaly days (WAD), in striking contrast to the severe attenuation of HF radio waves. This peculiar enhancement of the field strength may be ascribed to an increase in the reflection coefficient. The analysis also demonstrates that the reflection height is lower on WAD, which seems to be associated with enhancements of ionization in the D-region. Moreover, it was found that WAD are characterized by an earlier occurrence in the morning and a delayed occurrence in the evening of pronounced interference maxima and minima, respectively.
- Publication:
-
Journal of Atmospheric and Terrestrial Physics
- Pub Date:
- December 1986
- DOI:
- 10.1016/0021-9169(86)90042-5
- Bibcode:
- 1986JATP...48.1233I
- Keywords:
-
- Diurnal Variations;
- Low Frequencies;
- Radio Attenuation;
- Wave Propagation;
- Winter;
- Anomalies;
- D Region;
- Data Processing;
- Field Strength;
- High Frequencies