Venus Atmospheric Circulation: An Update
- Paper number
IAC-07-A3.I.A.28
- Author
Dr. Sanjay Limaye, University of Wisconsin, United States
- Coauthor
Dr. Wojciech Markiewicz, Max Planck Institute for Solar System Research, Germany
- Coauthor
Dr. VMC Camera Team, Max Planck Institute for Solar System Research, Germany
- Coauthor
Dr. Dmitri Titov, Germany
- Year
2007
- Abstract
Since its discovery more than four decades ago, the rapid rotation of the atmosphere pf Venus faster than the underlying surface has remained a puzzle. At the cloud top level, atmospheric rotation rate varies with latitude from about 4.5 days at low latitudes to about three days at mid and high latitudes, compared to 243 days for the solid surface. This global circulation is organized into two giant vortices, one in each hemisphere. There are many similarities between the circulation of a tropical cyclone and the vortex circulation on Venus, despite the more than an order of magnitude difference in physical scale. Yet, we still do not know what maintains this circulation and how it originated. The main difficulty in understanding the circulation has been the lack of systematic data. The Venus Monitoring Camera on European Space Agency’s Venus Express mission has been returning CCD images of Venus since April 2006. Venus Express is orbiting Venus every 24 hours in a h8ighly elliptic polar orbit. The new imaging capability is an enormous improvement over previous imaging data obtained from previous missions to Venus beginning with Mariner 10 in 1974. The imaging provides an estimate of the large scale circulation on almost every orbit, except during periods of communication loss at conjunctions. These data and observations from other Venus Express instruments are providing new results on the details of the global cloud level circulation of Venus
- Abstract document