DPS 34th Meeting, October 2002
Session 13. Outer Planets: Atmospheric Dynamics, Clouds
Oral, Chair(s): G.S. Orton and K.A. Rages, Tuesday, October 8, 2002, 1:30-3:30pm, Room M

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[13.05] Numerical Simulations of Disturbances and Vortices in Jupiter's Strongest Jet

E. Garcia-Melendo (Esteve Duran Observatory Fundation, Seva, Spain), A. Sanchez-Lavega (Universidad País Vasco, Bilbao, Spain), T. Dowling (University of Louisville, USA), R. Morales-Juberías (Universidad País Vasco, Bilbao, Spain)

For a period of 10 years, from 1991 to 2001, seven anticyclonic vortices located a few tenths of degree to the south of the North Temperate Belt jetstream peak, the strongest one measured during both Voyager flybys, survived in that region of the planet (Garcia-Melendo et al. 2000). These vortices originated after the 1990 disturbance (Sanchez-Lavega et al. 1991). In order to try to understand the origin and evolution of all the observed phenomena and morphology in that region of Jupiter, computer simulations were carried out using the Explicit Planetary Isentropic Coordinate (EPIC) model (Dowling, 1998). In the simulations we used the vertical temperature profile given by Lindal et al. (1995), obtained from Voyager radio measurements, and extended to higher 500mbar pressure levels by using the pseudoadiabatic model of Hueso et al. (2001). The vertical zonal wind profile u(z) was assumed to follow the thermal wind law up to a certain transition pressure level above which it was assumed to be constant or follow a different amplitude law. This transition level was one of the variable parameters used in the simulations. Different meridional zonal wind profiles (Maxworthy, 1984; Limaye, 1986) and our HST profile (García-Melendo et al., 2001) were checked. Our results indicate that both, Limaye and HST zonal wind profiles are stable, but that the Maxworthy profile is unstable under certain conditions. Simulations also constrain the vertical atmospheric structure up to 6 bar for that region of the planet. After introducing the initial heat disturbance, an instability develops in the Maxworthy flow in the form of one vortex or a pair of them, whose properties match those observed in the same region in Jupiter.

This work was supported by the Spanish MCYT Plan Nacional de Astronomía y Astrofísica 2000-0932 and by the Esteve Duran Observatory Foundation in Seva. It also made use of the computing facilities at CESCA in Barcelona.

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Bulletin of the American Astronomical Society, 34, #3< br> © 2002. The American Astronomical Soceity.