Atlantic Meridional Overturning Circulation (AMOC) from the OCCIPUT ensemble hindcasts and climatological simulations

The MEOM team in Grenoble (France) has produced for the OCCIPUT project (OCCIPUT) three NEMO-based ocean/sea-ice 1/4° ensemble hindcasts at global scale and over the North Atlantic. The members of each ensemble hindcast were started from slightly perturbed initial conditions, and then driven by the same atmospheric forcing derived from reanalyses. Time-dependent ensemble means provide the atmospherically-forced fluctuations of model fields, and time-dependent ensemble deviations provide their chaotic intrinsic fluctuations. These ensemble hindcasts are complemented by two long climatological global simulations, performed with slightly different model setups, which give access to the ”pure” chaotic intrinsic variability that spontaneously emerges under seasonal forcing.
The present dataset contains AMOCz (Atlantic Meridional Overturning Circulation in geopotential coordinates) yearly fields from the following simulations:
- the ORCA025.L75-OCCITENS global 1960-2015 ensemble hindcast (50 members),
- the NATL025-GSL301 North Atlantic 1993-2012 ensemble hindcast (50 members),
- the NATL025-TCLB300 North Atlantic 1993-2012 ensemble hindcast (10 members), 
- the ORCA025-MJM01 330-year global climatological simulation (1 member),
- the ORCA025.L75-MOCCITCLIM 327-year global climatological simulation (1 member).
AMOCz is defined as the yearly averaged, zonally integrated northward volume transport cumulated in the vertical throughout the Atlantic Ocean. AMOCz is provided for each simulation as a function of latitude, depth, year (and  member for the 3 ensemble hindcasts). This corresponds to the  `amoc` variable in the files, with   `nav_lat`, `depthw`, `time_counter` (and `ensmb`) dimensions respectively. The maximum in the vertical of AMOCz below 500m (i.e. the strength of the AMOC upper cell) is also provided with no depth coordinate in files whose names contain the ”_max_” string.
This dataset was first described and analyzed in Leroux et al (2018): Intrinsic and Atmospherically Forced Variability of the AMOC: Insights from a Large-Ensemble Ocean Hindcast (https://doi.org/10.1175/JCLI-D-17-0168.1) where more details can be found. The OCCIPUT ensemble hindcasts are described in Bessières et al (2017): Development of a probabilistic ocean modelling system based on NEMO 3.5 : application at eddying resolution (https://doi.org/10.5194/gmd-10-1091-2017). Please cite these two publications if you are using these AMOC data.

Advise: please consider detrending AMOCz time series non-linearly before computing ensemble statistics as discussed in Leroux et al (2018) and illustrated in the example notebook: https://github.com/stephanieleroux/SHARED_NOTEBOOKS/blob/master/2026-03-10_AMOC-demo-FIG6b.ipynb