ORCA12, a global ocean-ice model at 1/12° : successes, shortcomings and their impact on ocean forecasting
Abstract
Mercator-Ocean currently uses ORCA12, a global 1/12° model based on the NEMO modelling platform, which is a the core of CMEMS. The ORCA12 model has also been used by the DRAKKAR group to perform multi-decadal simulations forced by the atmosphere, without data assimilation. In these forced ocean-ice experiments, the benefit of the 1/12° resolution appears clearly, for the representation of fronts and mesoscale eddies. However, the pathways of energetic currents are not yet robust at 1/12°: the North Atlantic current is an exemple, as is the Agulhas retroflexion. The time-mean currents in ORCA12 are found to be sensitive to parameterizations, numerical schemes, and atmospheric forcing. These sensitivities are not unexpected, considering the highly nonlinear dynamics of eddy-induced mean recirculations and flow-topography interactions. We attempt to quantify the influence of biases in the position of energetic currents on the error growth during a forecast.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2017
- Bibcode:
- 2017EGUGA..1917950T