Fig. 1

Kinetic energy spectrum of Jupiter’s cloud layer (in units of Ω²R²), obtained by Galperin et al. (2014) from Cassini images. Spectra are projected onto spherical harmonics (with total wavenumber index n) and decomposed into the zonal mean flow E_Z(n) (1, thin line) and residual KE E_R(n) (2, thick line), such that total energy E_T(n) = E_Z(n) + E_R(n). The analysis used the CB2 filter images with a native resolution of 0.05° pixel⁻¹ and a correlation box size of 0.95°, corresponding to a spectral resolution limit of around 1° or n ≈ 200