Dynamics of Saturn's South Polar Vortex
Ulyana A. Dyudina,1*
Andrew P. Ingersoll,1
Shawn P. Ewald,1
Ashwin R. Vasavada,2
Robert A. West,2
Anthony D. Del Genio,3
John M. Barbara,3
Carolyn C. Porco,4
Richard K. Achterberg,5
F. Michael Flasar,5
Amy A. Simon-Miller,5
Leigh N. Fletcher2,6
The camera onboard the Cassini spacecraft has allowed us to observe many of Saturn's cloud features. We present observations of Saturn's south polar vortex (SPV) showing that it shares some properties with terrestrial hurricanes: cyclonic circulation, warm central region (the eye) surrounded by a ring of high clouds (the eye wall), and convective clouds outside the eye. The polar location and the absence of an ocean are major differences. It also shares properties with the polar vortices on Venus, such as polar location, cyclonic circulation, warm center, and long lifetime, but the Venus vortices have cold collars and are not associated with convective clouds. The SPV's combination of properties is unique among vortices in the solar system
1 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
3 Goddard Institute for Space Studies, NASA, 2880 Broadway, New York, NY 10025, USA.
4 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA.
5 NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, USA.
6 Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK.
* To whom correspondence should be addressed. E-mail: ulyana{at}gps.caltech.edu
