Jupiter's and Saturn's convectively driven banded jets in the laboratory

Peter L. Read (1) , Hiro Yashuhiro Yamazaki (1) , Stephen R Lewis (1) , Paul D. Williams (1) , Kuniko Miki-Yamazaki (1) , Joël Sommeria (2) , Henri Didelle (2) , Adam M. Fincham

1 Clarendon Laboratory [Oxford]
2 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]

The banded patterns of cloud and wind are among the most striking features of the atmospheres of Jupiter and Saturn, but their dynamical origin remains poorly understood. Most approaches towards understanding zonation so far (also in the terrestrial oceans) have used highly idealized models to show that it might originate from dynamical anisotropy in a shallow turbulent fluid layer due to the planetary β‐effect. Here we report the results of laboratory experiments, conducted on a 14‐m diameter turntable, which quantitatively confirm that multiple zonal jets may indeed be generated and maintained by this mechanism in the presence of deep convection and a topographic β‐effect. At the very small values of Ekman number (≤2 × 10−5) and large local Reynolds numbers (≥2000, based on jet scales) achieved, the kinetic energy spectra suggest the presence of both energy‐cascading and enstrophy‐cascading inertial ranges in addition to the zonation near twice the Rhines wave number.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Peter L. Read, Hiro Yashuhiro Yamazaki, Stephen R Lewis, Paul D. Williams, Kuniko Miki-Yamazaki, et al.. Jupiter's and Saturn's convectively driven banded jets in the laboratory. Geophysical Research Letters, 2004, 31, ⟨10.1029/2004GL020106⟩. ⟨hal-00260763⟩