Venusian nightside ionosphere in the years of low and high solar activity from radio occultation data
Abstract
Radio-occulation measurement data obtained in years of low solar activity (Mariner-10 data from 1974) and high solar activity (Pioneer-Venus data from 1978-1979) are analyzed. It is shown that, irrespective of the phase of the solar cycle, the electron density in the upper maximum decreases, on the average, with increasing solar zenith angle in the range 95-120 deg. In the years of low solar activity, the peak values of electron density in the upper maximum are lower than those corresponding to years of high solar activity. Two-maximum electron density distributions occur more often in years of low solar activity than in years of high solar activity. In addition, it is shown that the height extent of the Venusian nightside ionosphere is considerably less in years of low solar activity than in years of high solar activity.
- Publication:
-
Lausanne International Astronautical Federation Congress
- Pub Date:
- October 1984
- Bibcode:
- 1984laus.iafcQ....S
- Keywords:
-
- Ionospheric Sounding;
- Night Sky;
- Planetary Ionospheres;
- Radio Occultation;
- Solar Activity Effects;
- Venus Atmosphere;
- Ionospheric Disturbances;
- Ionospheric Electron Density;
- Mariner 10 Space Probe;
- Pioneer Venus Spacecraft;
- Lunar and Planetary Exploration