University of Kansas Cassini Studies

(DRAFT) A Three-Dimensional MHD Model of Plasma Flow Around Titan S. A. Ledvina and T. E. Cravens

The main conclusions from our 3-D MHD model of plasma flow around Titan are listed below.

1. For the upstream plasma, conditions are similar to those observed by Voyager 1. The model predicted a narrow wake behind Titan as seen by Voyager. Alfven wings are present as suggested by Ness et al. [1982]. Cassini should look for these.
2. Our 3-D model confirms that the overall flow pattern predicted by the 2-D model of Cravens et al. [1997] is valid in the ram and flank regions.
3. Changes in the magnetosonic mach number of the incident plasma have a large effect on the interaction with Titan and the structure of the wake. In the supermagnetosonic cases the wake is spread out more than in the submagnetosonic case. A shock is present in the supermagnetosonic cases, but the Alfven wings have vanished.

The results presented here explain many aspects of plasma flow around Titan. However, a more realistic obstacle and higher spatial resolution are needed to fully explain the interaction between Titan and the incident plasma flow. Furthermore, hybrid simulations are necessary to fully explain the plasma dynamics due to the large gyroradii of ions in the upstream magnetospheric plasma flow. More work is also needed on neutral exosphere models to better understand the role of mass loading near Titan on the plasma dynamics. And finally, the Cassini mission is needed to collect data on Saturn's magnetosphere and its interaction with Titan.

REFERENCES

Return to Titan 3D Model Abstract and Index Page.
Return to Space Physics Main Cassini Page.
Return to Titan Studies Main Page.

Last modified February 6, 2004 Tizby Hunt-Ward tizby@ku.edu