Abstract
AbstractUsing images from the Cassini spacecraft, we analyzed three ribbon waves in Saturn's 42°N eastward jet at 45°N, 42°N, and 39°N planetocentric latitudes. In this report, we demonstrate that the morphology, wavelength, and propagation of the ribbon waves are consistent with barotropic Rossby waves with a smaller baroclinic component. We report on the appearance and disappearance of these waves during Cassini's mission. We suggest that the temporal evolution of these waves are related to the great Saturn storm of 2010–2011.
Highlights
One of the prominent features of Saturn’s atmosphere discovered by the Voyager spacecraft was a dark, sinuous line encircling the planet at 42∘N latitude, which was dubbed the ribbon wave after its visual appearance (Smith et al, 1981, 1982)
We demonstrate that the morphology, wavelength, and propagation of the ribbon waves are consistent with barotropic Rossby waves with a smaller baroclinic component
Using images taken by Cassini, we have identified the ribbon waves as Rossby waves, that is, planet-scale waves that are common in atmospheres, including that of the Earth
Summary
One of the prominent features of Saturn’s atmosphere discovered by the Voyager spacecraft was a dark, sinuous line encircling the planet at 42∘N latitude (we use planetocentric latitude throughout this report), which was dubbed the ribbon wave after its visual appearance (Smith et al, 1981, 1982). We use the term ribbon and ribbon wave throughout to refer to planet-encircling features that have north-south oscillations, visible as distinct divisions within, or boundaries between, cloud bands. This is a morphological classification, as features with a similar appearance (e.g., Jupiter’s ribbon, Cosentino et al, 2015, and 20∘S wave, Rogers et al, 2016) may have different dynamical origins, while some features with broadly similar dynamics (e.g., Jupiter’s equatorial hot spots (Choi et al, 2013)) do not have ribbon-like morphologies. Because of its presence at a sharp meridional potential vorticity gradient and its north-south meandering, the ribbon was assumed to be a Rossby wave—a planetary-scale wave with the restoring force provided by a positive potential vorticity gradient
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
