Publication Date:
2011-08-19
Description:
A one-dimensional model of the Venus thermosphere has been constructed which includes computation of the heating efficiency of solar ultraviolet radiation, heat loss by radiation to space of infrared-active species, thermal transport by molecular and eddy conduction, and viscous dissipation. By comparing model predictions with results obtained from the Pioneer Venus Orbiter spacecraft, the results indicate that energy transport parameterized by eddy heat conduction plays a dominant role in determining thermospheric temperature. It is suggested that there exists a feedback mechanism linking heating and thermospheric circulation such that eddy cooling maintains an asymptotic temperature of about 300 K for both solar-maximum and solar-minimum conditions. The variation in thermospheric temperature with solar zenith angle, atomic oxygen-mixing ratio, rate of vibrational excitation of CO2 by ground-state O atoms, and the assumed transfer of O(1D) electronic energy to CO2 vibrational energy are also studied.
Keywords:
LUNAR AND PLANETARY EXPLORATION
Type:
Icarus (ISSN 0019-1035); 64; 205-220
Format:
text
Permalink
