Thermal Structure and Energy Influx to the Day-and Nightside Venus Ionosphere

  title={Thermal Structure and Energy Influx to the Day-and Nightside Venus Ionosphere},
  author={William C. Knudsen and Karl Spenner and Robert C. Whitten and John R. Spreiter and Kent L. Miller and V. Novak},
  pages={105 - 107}
Pioneer Venus in situ measurements made with the retarding potential analyzer reveal strong variations in the nightside ionospheric plasma density from location to location in some orbits and from orbit to orbit. The ionopause is evident at night as a relatively abrupt decrease in the thermal plasma concentration from a few hundred to ten or fewer ions per cubic centimeter. The nightside ion and electron temperatures above an altitude of 250 kilometers, within the ionosphere and away from the… 
Electron temperature and heat flow in the nightside Venus ionosphere
The electron energy budget of the nightside Venus ionosphere is analyzed by comparing two-dimensional solutions of the heat conduction equation with an empirical model of the electron temperature
Empirical models of the electron temperature and density in the Venus ionosphere
Empirical models of the electron temperature and density of the Venus ionosphere have been derived from Pioneer Venus measurements acquired between December 10, 1978, and August 9, 1979. This time
The dynamic behavior of the Venus ionosphere in response to solar wind interactions
Measurements of electron density and temperature by the Pioneer Venus orbiter electron temperature probe (OETP) are used to describe the dynamic behavior of the Venus ionosphere and to begin to
Solar zenith angle dependence of ionospheric ion and electron temperatures and density on Venus
Data from the first year of operation of the Pioneer Venus orbiter retarding potential analyzer are presented, showing the variation with solar zenith angle of median values of ion and electron
Variability of dayside electron temperature at Venus
Langmuir probe measurements on Pioneer Venus Orbiter show that electron temperature (Te) profiles exhibit two distinct regions. The lower, but more extended region is in the main ionosphere where Te
Holes in the nightside ionosphere of Venus
Measurements of electron density and temperature by the Pioneer Venus orbiter electron temperature probe have been employed to examine the characteristics and morphology of ionospheric holes in the
The location of the dayside ionopause of Venus - Pioneer Venus Orbiter magnetometer observations
The location of the dayside Venus ionopause, as observed by the Pioneer Venus Orbiter, is shown to depend on the magnetic pressure in the shocked, highly compressed solar wind plasma just outside the
Ion energetics in the Venus nightside ionosphere
The transport time required for the ionospheric ion gas to flow through an arc of one radian across the Venus terminator at the observed horizontal speed is short in comparison with the time required
Observations of the dayside ionopause and ionosphere of Venus
Some of the principal features of the dayside solar wind ionosphere interaction at Venus are presented. The dayside ionopause and ionosphere are observed to respond dramatically to solar wind
On the maintenance of the Venus nightside ionosphere: Electron precipitation and plasma transport
Suprathermal integral electron spectra between 5 and 45 eV measured by the Pioneer Venus orbiter RPA are presented for the Venus nightside ionosphere. The observed integral electron flux is


Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere
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.
Thermal Structure and Major Ion Composition of the Venus Ionosphere: First RPA Results from Venus Orbiter
Thermal plasma quantities measured by, the retarding potential analyzer (RPA) are, together with companion Pioneer Venus measurements, the first in situ measurements of the Venus ionosphere. High
Ionosphere of Venus: First Observations of the Dayside Ion Composition Near Dawn and Dusk
The first in situ measurements of the composition of the ionosphere of Venus are provided by independent Bennett radio-frequency ion mass spectrometers on the Pioneer Venus bits and orbiter
Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition
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.
Venus: Mass, Gravity Field, Atmosphere, and Ionosphere as Measured by the Mariner 10 Dual-Frequency Radio System
Analysis of the Doppler tracking data near encounter yields a value for the ratio of the mass of the sun to that of Venus of 408,523.9 � 1.2, which is in good agreement with prior determinations
Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations
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
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  • Geophys. Res. re theory of Lett
  • 1979
The retarding potential analyzer experiment is