Open AccessSuppression of the Rhines effect and the location of vortices on Saturn
Author(s) -
Penny A. B.,
Showman A. P.,
Choi D. S.
Publication year - 2010
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009je003384
Subject(s) - rossby wave , rossby radius of deformation , vortex , physics , saturn , latitude , turbulence , rossby number , geophysics , radius , atmospheric sciences , geology , meteorology , astrophysics , planet , astronomy , computer security , computer science
Saturn's atmosphere contains numerous vortices that reside predominantly within specific localized latitude bands. Two‐dimensional turbulence theory predicts that vortices which do form are readily destroyed as they interact with dispersive Rossby waves in a process called the “Rhines effect,” which acts to organize turbulent energy into alternating zonal flows through the interaction of Rossby waves and turbulence of similar scales. Observations show that at some latitudes, vortices are more prevalent, suggesting that Rossby waves are suppressed in these regions. Following the method applied to Jupiter by Theiss (2006), we generalize the 2‐D Rhines scale to include depth‐dependent flow with a finite deformation radius; this allows for a simple estimate of the conditions under which Rossby waves are suppressed in the cloud layer. We then compare the latitudes of known vortices to the predicted latitudes where Rossby waves may be suppressed on Saturn. We find a good correlation, suggesting that, as on Jupiter, Rossby wave suppression helps explain the prevalence of vortices at specific latitudes on Saturn.