Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations

@article{Kliore1979InitialOO,
  title={Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations},
  author={A. J. Kliore and Indu R. Patel and Andrew F. Nagy and Thomas E. Cravens and Tamas I. I. Gombosi},
  journal={Science},
  year={1979},
  volume={205},
  pages={102 - 99}
}
Pioneer Venus orbiter dual-frequency radio occultation measurements have produced many electron density profiles of the nightside ionosphere of Venus. Thirty-six of these profiles, measured at solar zenith angles (χ) from 90.60� to 163.5�, are discussed here. In the "deep" nightside ionosphere (χ > 110�), the structure and magnitude of the ionization peak are highly variable; the mean peak electron density is 16,700 � 7,200 (standard deviation) per cubic centimeter. In contrast, the altitude of… 
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References

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TLDR
Fourteen profiles of electron density in the ionosphere of Venus were obtained by the dual-frequency radio occulation method with the Pioneer Venus orbiter between 5 and 30 December 1978 and are consistent with models in which O2+ dominates near the ionization peak and is replaced by O+ at higher altitudes.
Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere
TLDR
High nocturnal temperatures and the existence of a well-defined nightside ionside ionopause suggest that energetic processes occur across the top of the entire nightside ionosphere, maintaining elevated temperatures.
The Mariner 10 Radio Occultation Measurements of the Ionosphere of Venus
Abstract Data from the Mariner 10 radio occultation experiment have been utilized to determine the vertical electron density distribution in the ionosphere of Venus. The ingress measurements, which
Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition
TLDR
The Bennett radio-frequency ion mass spectrometer on the Pioneer Venus orbiter is returning the first direct composition evidence of the processes responsible for the formation and maintenance of the nightside ionosphere, revealing a surprising abundance of O+ from the dayside leading to the formation of O2+ through charge exchange with CO2.
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Measurements of the composition, temperature, and diurnal variations of the major neutral constituents in the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer
We wish to acknowledge the contributions of
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