Flow-field correction method to constrain AMOC in coupled model (IPSL-CM6A-LR)

We use the standard version of IPSL-CM6A-LR (Boucher et al., 2020). The ocean component of IPSL-CM6A-LR is the NEMO oceanic model Version 3.6. In the NEMO model, we replace dynhpg.F90 by a modified version of the routine that implements the flow-field correction method. namelist_ORCA1_cfg is the modified namelist to activate the flow field correction, set the parameters and read the input temperature, salinity and the mask.

Additional files are provided to the model. data_tem_bigthetao_weak1.5LFC.nc and data_tem_bigthetao_1.5LFC.nc are the salinity and temperature to constrain to the AMOC to strong state. data_sal_sa_1.5LFC.nc and data_sal_sa_weak1.5LFC.nc are the salinity and temperature to contrain to the AMOC to weak state.

Some of the main outputs of the simulations are given. These outputs are the simulated annual mean ensemble mean (3 members) of ocean heat content (heatc, in J/m2), sea surface salinity (sos, in psu), precipitation (precip, in kg/(s*m2)), sea surface temperature (tos, in degC) and meridional streamfunction (diaptrW, Sv). The initial states of the 3 members are sampled in the years of 1850, 2000 and 2080 of the CMIP6 piControl simulation available on ESGF, corresponding to neutral, strong, and weak AMOC states respectively. “strong” in the filenames refers to simulations where the AMOC is constrained to the strong state (i.e., using the input data_tem_bigthetao_1.5LFC.nc and data_sal_sa_1.5LFC.nc). Vice versa for “weak” (i.e. using data_tem_bigthetao_weak1.5LFC.nc and data_sal_sa_weak1.5LFC.nc).