The new NEMO ocean model configuration NNATL12 was constructed in 2017 in the frame of joint work of IORAS and IGE scientists and engineers (Polina Verezemskaya, Jean-Marc Molines, Aurelie Albert). NNATL12 is the model of Northern North Atlantic and covers the region between 47-70N and 87W-18E, with 1/12˚ horizontal resolution (approximately 3-5 km) and 75 fixed vertical levels. The configuration uses the highest among already existent official configurations number of open boundaries – three – northern, southern and western. Lateral boundary conditions were set from last generation ocean reanalysis GLORYS12V1 with 1/12˚ horizontal resolution. The configuration is numerically lightweight thus easing multiple testing of the model sensitivity to various dynamical core set-ups, physical processes parameterizations, and boundary condition usage. Different atmospheric data were used to force model on the upper open boundary: the model was tested with widely used DFS5.2 atmospheric forcing and newly presented by IORAS NAAD data was used for testing the model on sensitivity to the representation of mesoscale atmospheric processes.
Configuration domain is chosen to include most of the climate-driving processes: deep convection in Labrador and Irminger Seas, Subpolar Gyre current system, Arctic waters overflow, and others, all together driving the global ocean conveyor.


Model NEMO 3.6 / NEMO 4
Time period 1992 – 2015
Horizontal resolution 1/12˚ (3-5 km)

(402×934 points)

Vertical levels 75 levels
Ocean forcing GLORYS2v4


Advection scheme UBS/UBS (momentum/tracers)

atmospheric forcing

Ocean – DFS5.2
Ocean – HiRes NAAD
Ocean – LoRes NAAD