Wavelike perturbations observed in the neutral thermosphere of Venus
Article first published online: 20 SEP 2012
This paper is not subject to U.S. copyright. Published in 1988 by the American Geophysical Union.
Journal of Geophysical Research: Space Physics (1978–2012)
Volume 93, Issue A10, pages 11237–11245, 1 October 1988
How to Cite
1988), Wavelike perturbations observed in the neutral thermosphere of Venus, J. Geophys. Res., 93(A10), 11237–11245, doi:10.1029/JA093iA10p11237., , , and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 19 MAY 1988
- Manuscript Received: 5 JAN 1988
Wavelike perturbations are evident in the neutral thermosphere measurements of He, N, O, N2, and CO2 by the Pioneer Venus orbiter neutral mass spectrometer. In the wavelength range from 100 to 600 km the amplitudes of the various species are comparable in magnitude, with CO2 having the largest amplitude, and with helium out of phase with respect to the heavier species. On the dayside the small scale variations of CO2 and N2 increase with increasing altitude from 170 to 210 km, with CO2 having the largest slope. Simple and complex wave structures are observed including wave trains and pulselike events. There is more activity during nighttime than during daytime and larger values of the activity occur in the vicinity of the predawn and postdusk terminator sectors. Below 160 km the standard deviation of the CO2 density on the nightside is 12%, about 3 times the daytime value. The data are consistent with the interpretation that the density perturbations are due to gravity waves propagating upward from the lower thermosphere.