Physics
Scientific paper
Dec 1992
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992lpico.789...47i&link_type=abstract
In Lunar and Planetary Inst., Papers Presented to the International Colloquium on Venus p 47-48 (SEE N93-14288 04-91)
Physics
Atmospheric Circulation, Superrotation, Venus Atmosphere, Wind Velocity, Angular Momentum, Angular Velocity, Atmospheric Physics, Equatorial Atmosphere, Tides, Vortices
Scientific paper
The superrotation of the Venus atmosphere is a major unanswered problem in planetary science. At cloud-top levels (65-70 km altitude) the atmosphere rotates with a five-day period, corresponding to an equatorial wind speed of 90 m/s. Angular velocity is roughly constant on spherical shells, and decreases linearly with altitude to zero at the surface. The direction of rotation is the same as that of the solid planet, which is retrograde--opposite to the direction of orbital motion, but the 5-day period is short compared to the 243-day spin period of the solid planet or to the mean solar day, which is 117 Earth-days at the surface. The problem with the superrotation is that shearing stresses tend to transfer angular momentum downward, and would slow the atmosphere until it is spinning with the solid planet. Some organized circulation pattern is counteracting the tendency, but the pattern has not been identified. A simple Hadley-type circulation cannot do it because such a circulation is zonally symmetric and Hide's Theorem states that in an axisymmetric circulation an extremum in angular momentum per unit mass M can exist only at the surface. Venus violates the last condition, having a maximum of retrograde M on the equator at 70-80 km altitude. This leaves waves and eddies to maintain the superrotation but the length scales and forcing mechanisms for these motions need to be specified. Possible forcing mechanisms associated with waves, eddies and tides are discussed.
No associations
LandOfFree
Dynamics of the Venus atmosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dynamics of the Venus atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamics of the Venus atmosphere will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1138469