Abstract
The energy spectra of the zonal flows on Jupiter and Saturn obey the
scaling law EZ (n) = CZ (Ω /R)2
n-5 in the range of total wave numbers n not affected by
large scale friction (Ω and R are the rotation rate and the radius
of the planet, and CZ is an order-one constant). These
spectra broadly resemble their counterpart obtained in our recent
simulations [Huang et al., Phys. Fluids, 13, 225-240 (2001)] that
represents a strongly anisotropic flow regime evoked by the planetary
vorticity gradient. It is conjectured that this regime governs the large
scale circulations and the multiple zonal jets on giant planets. More
recent simulations with linear drag also exhibit the same behavior.
Preliminary comparisons with the scarce data available for the other two
giant planets are consistent with the above scaling. The combined effect
of the energy condensation in the lowest zonal modes and the large scale
friction on generation and maintenance of strong equatorial jets will be
discussed.
| Original language | English GB |
|---|---|
| State | Published - 1 Nov 2001 |