Investigating the predictability of the Southern Ocean dynamics through ensemble simulation hindcasts

The Southern Ocean (SO) dynamics, and the various fronts of the Antarctic Circumpolar Current in particular, are well known to display a very energetic variability covering a wide range of spatial and temporal scales. Since a substantial fraction of such variability is known to be intrinsic, and therefore basically chaotic, predictability in this part of the world ocean is particularly poor. In this context, the IPSODES project will investigate the predictability of the SO dynamics through ensemble simulation (ES) hindcasts analyzed by means of various statistical techniques supported by dynamical interpretations. Existing state-of-the-art eddy-permitting global ocean-sea-ice model ESs and coupled global atmosphere-ocean-sea-ice model ESs developed for decadal climate predictions will be used. Moreover, new ESs performed with a regional ocean model specifically developed for this project will also be carried out: sensitivity numerical experiments to assess model uncertainty will be performed with these new simulations. By improving our understanding of the predictability properties of oceanic variability, IPSODES will contribute toward more reliable predictions of the SO dynamics. This will in turn (i) contribute to enhance ocean modelling systems in the framework of the GIPPS, (ii) suggest improvements to the oceanic observational system, and (iii) provide further knowledge in support of coordinated research on interannual to decadal climate predictability and predictions (CMIP6-DCPP).