Radio-wave absorption in the equatorial ionosphere
Abstract
Model computations of equatorial absorption are presented and discussed in relation to available experimental results. There is good agreement between observed total absorption and the model computations for frequencies above about 2.4 MHz. Below this frequency, the observed values are low relative to the computed ones. It is suggested that these low values might in fact explain the inverse-frequency law so far observed for absorption below about 3 MHz near the Equator. A comparison of the experimental values with model computations also shows that in the E-region, collision frequencies deduced from atmospheric pressure are more consistent with observed absorption than the observed values of collision frequencies listed by Thrane and Piggott (1966). The numerical results further indicate that less than 50% of the total absorption at and above 2 MHz occurs in the D-region, contrary to the 80 to 90% contribution reported by several experimental workers.
- Publication:
-
Journal of Atmospheric and Terrestrial Physics
- Pub Date:
- January 1975
- DOI:
- 10.1016/0021-9169(75)90085-9
- Bibcode:
- 1975JATP...37....1O
- Keywords:
-
- Atmospheric Attenuation;
- Electromagnetic Absorption;
- Ionospheric Propagation;
- Radio Attenuation;
- Tropical Regions;
- Atmospheric Models;
- Collision Rates;
- D Region;
- E Region;
- Frequency Response;
- Ionospheric Electron Density;
- Latitude;
- Vertical Distribution