DPS 35th Meeting, 1-6 September 2003
Session 48. Outer Planets/Gas Giants II
Oral, Chairs: L. A. Young and H. B. Hammel, Saturday, September 6, 2003, 1:30-3:00pm, DeAnza I-II

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[48.02] Energy Balance in Jupiter's Middle Atmosphere: Radiation and Gravity Waves

L.A. Young (SwRI), R.E. Young (NASA Ames Research Center), R.V. Yelle (Lunar and Planetary Lab, University of Arizona)

The quantitative similarity of temperature fluctuations in the jovian and terrestrial middle atmospheres strengthens the case for breaking gravity waves in Jupiter's middle atmosphere.1 Breaking gravity waves directly contribute to both heating (by local deposition of wave energy) and cooling (by turbulent mixing of potential temperature). The net effect2 depends on eddy diffusion and the eddy Prandtl number, Pr, the ratio of the eddy diffusion coefficient for momentum to that for temperature. In addition, breaking waves can deposit momentum, indirectly modifying temperatures through changes in the mean circulation.

The value of Pr in Jupiter's middle atmosphere is unconstrained, hampering a comparison of heating and cooling from radiation3 to that from breaking gravity waves. For Jupiter's eddy diffusion profile,4 breaking gravity waves lead to net cooling for Pr < 1.7 and net heating otherwise. For a wide range of Pr, (1 < Pr < 20, based on numerical models of breaking waves),radiation dominates over gravity waves in the lower stratosphere (10-100 mbar). However, gravity wave heating dominates over radiation in the upper stratosphere (1-10 \mubar) for Pr>10.

We will discuss the evidence for jovian stratospheric gravity waves, the competing heating and cooling effects of gravity waves, and the roles of radiation and breaking gravity waves on Jupiter's stratospheric energy balance.

\noindent [1] Young, L.A., R.V. Yelle, R.E. Young, A. Seiff, D.B. Kirk 2003 Gravity waves in Jupiter?s stratosphere, as measured by the Galileo ASI experiment, Icarus, submitted. [2] Strobel et al., 1985. JGR 90, 13067-13072. [3] Yelle et al., 2001. Icarus 152, 331-346. [4] Moses et al., 2002. In Jupiter: Planet, Satellites, and Magnetosphere. Cambridge U. Press.

\noindent The work was supported, in part, by NASA's Planetary Atmsopheres program, through RTOP 344-33-20-03 (REY) and NEG5-9214 (RVY).

The author(s) of this abstract have provided an email address for comments about the abstract: layoung@boulder.swri.edu

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