Other GCM Configurations worth knowing about

3D DYNAMICO setup

Due to the rich dynamical activities in their atmospheres (banded zonal jets, eddies, vortices, storms, equatorial oscillations,...) resulting from multi-scale dynamic interactions, the Global Climate Modelling of the giant planet requires to resolve eddies arising from hydrodynamical instabilities to correctly establish the planetary-scaled jets regime. To this purpose, their Rossby radius deformation $$L_D$$, which is the length scale at which rotational effects become as important as buoyancy or gravity wave effects in the evolution of the flow about some disturbance, is calculated to determine the most suitable horizontal grid resolution. At mid-latitude range, for the giant planets, $$L_D$$ is of the same order of magnitude as that of the Earth. As the giant planets have a size of roughly 10 times the Earth size (i.e., Jupiter and Saturn), the modelling grid must be of a horizontal resolution of 0.5$$^{\circ}$$ over longitude and latitude (vs 5$$^{\circ}$$ for the Earth), considering 3 grid points to resolved $$L_D$$. Moreover, these atmospheres are cold, with long radiative response time which needs radiative transfer computations over decade-long years of Jupiter, Saturn, Uranus or Neptune (depending on the planet).

To this purpose, we use a dynamical core suitable and numerical stable for massive parallel ressource computations: DYNAMICO [Dubos et al,. 2015].