Abstract Temporally and longitudinally averaged circulation determined from images acquired since 1979 from the Pioneer Venus orbiter has shown significant changes in the zonal and meridional flow. Accordingly the solar-locked structure in the zonal and meridional components of the cloud motions also changes with time. Mechanisms for such changes remain unknown, although planetary waves and a slight modulation of the cloud level have been suggested. Remarkably, the solar-locked horizontal divergence pattern as well as the tidal magnitudes show similar structure over time. Further, the average global thermal and cloud structure as well as the general appearance of Venus have not changed dramatically. Decomposition of the solar locked structure into diurnal and semi-diurnal components suggests that night-side zonal flow may be 10–20 ms−1 faster than the average day-side flow. Is the apparent solar-locked circulation really a signature of the tides or an artifact of solar locked cloud structure? Many aspects of the atmospheric circulation remain unknown-horizontal and vertical structure on the nightside and at levels higher and lower than the ultraviolet cloud features, source(s) and sink(s) of ultraviolet absorber(s), meridional transports of heat, momentum and water vapor at different levels. Balloons and entry probes at different locations and altitudes can help, as also multispectral infrared imaging of the nightside.
Venus atmospheric circulation: Known and unknown
Advances in Space Research ; 10 , 5 ; 91-101
1989-01-01
11 pages
Article (Journal)
Electronic Resource
English
Venus atmospheric circulation - Known and unknown
NTRS | 1990
|Online Contents | 1999
NTIS | 2002
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