Global climate modeling of Saturn's atmosphere. Part II: multi-annual high-resolution dynamical simulations
arXiv:1811.01250 · doi:10.1016/j.icarus.2019.07.011
Abstract
The Cassini mission unveiled the intense and diverse activity in Saturn's atmosphere: banded jets, waves, vortices, equatorial oscillations. To set the path towards a better understanding of those phenomena, we performed high-resolution multi-annual numerical simulations of Saturn's atmospheric dynamics. We built a new Global Climate Model [GCM] for Saturn, named the Saturn DYNAMICO GCM, by combining a radiative-seasonal model tailored for Saturn to a hydrodynamical solver based on an icosahedral grid suitable for massively-parallel architectures. The impact of numerical dissipation, and the conservation of angular momentum, are examined in the model before a reference simulation employing the Saturn DYNAMICO GCM with a latitude-longitude resolution is considered for analysis. Mid-latitude banded jets showing similarity with observations are reproduced by our model. Those jets are accelerated and maintained by eddy momentum transfers to the mean flow, with the magnitude of momentum fluxes compliant with the observed values. The eddy activity is not regularly distributed with time, but appears as bursts; both barotropic and baroclinic instabilities could play a role in the eddy activity. The steady-state latitude of occurrence of jets is controlled by poleward migration during the spin-up of our model. At the equator, a weakly-superrotating tropospheric jet and vertically-stacked alternating stratospheric jets are obtained in our GCM simulations. The model produces Yanai (Rossby-gravity), Rossby and Kelvin waves at the equator, as well as extratropical Rossby waves, and large-scale vortices in polar regions. Challenges remain to reproduce Saturn's powerful superrotating jet and hexagon-shaped circumpolar jet in the troposphere, and downward-propagating equatorial oscillation in the stratosphere.
arXiv comment68 pages, 23 figures, published in Icarus https://doi.org/10.1016/j.icarus.2019.07.011
References in corpus (25)
- Equatorial superrotation on tidally locked exoplanets
- 3D climate modeling of close-in land planets: Circulation patterns, climate moist bistability and habitability
- Constraints on Deep-seated Zonal Winds Inside Jupiter and Saturn
- Formation of Jets and Equatorial Superrotation on Jupiter
- Exploring the faint young Sun problem and the possible climates of the Archean Earth with a 3-D GCM
- Random changes of flow topology in two dimensional and geophysical turbulence
- Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling
- Mechanisms of jet formation on the giant planets
- Generation of equatorial jets by large-scale latent heating on the giant planets
- Dynamics of Saturn's great storm of 2010-2011 from Cassini ISS and RPWS
- Saturn's deep atmospheric flows revealed by the Cassini Grand Finale gravity measurements
- A Thermal Plume Model for the Martian Convective Boundary Layer
- Explaining Jupiter's magnetic field and equatorial jet dynamics
- Kinetic theory of jet dynamics in the stochastic barotropic and 2D Navier-Stokes equations
- Intercomparison of General Circulation Models for Hot Extrasolar Planets
- Scientific rationale of Saturn's in situ exploration
- The long-term steady motion of Saturn's Hexagon and the stability of its enclosed jet-stream under seasonal changes
- Transient conditions for biogenesis on low-mass exoplanets with escaping hydrogen atmospheres
- Dynamics of Saturn's Polar Regions
- Seasonal Evolution of Saturn's Polar Temperatures and Composition
- Disruption of Saturn's Quasi-Periodic Equatorial Oscillation by the Great Northern Storm
- Photochemistry, mixing and transport in Jupiter's stratosphere constrained by Cassini
- An Enduring Rapidly Moving Storm as a Guide to Saturn's Equatorial Jet's Complex Structure
- 2D photochemical modeling of Saturn's stratosphere. Part II: Feedback between composition and temperature
- Stratospheric aftermath of the 2010 Storm on Saturn as observed by the TEXES instrument. I. Temperature structure
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- Jupiter's Temperate Belt/Zone Contrasts Revealed at Depth by Juno Microwave Observations
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