Model output based on AWIESM2 (PI, MH, LIG, LGM, MIS3) for WMT analysis

This dataset contains the AWIESM2 model output required for Water Mass Transformation Analysis. All data are derived from equilibrium simulations of five climate states: PI : Pre-Industrial (control) MH: Mid-Holocene (~6 ka) LIG: Last Interglacial (~127 ka) LGM: Last Glacial Maximum (~21 ka) MIS3: Marine Isotope Stage 3 (~38 ka) Unless noted, fields are climatological monthly means (12 months) averaged over the final 100 model years of each simulation. The single exception is thewater mass transformation (WMT) analysis used for the winter-WMT figure, which requires the full 100-year monthly time series so that interannual spread(±1σ) can be computed; those files are provided under "wmt_100years/". Directory layout climatology/ : climatological monthly means, per experiment pi/ mh/ lig/ lgm/ mis/wmt_100years/ : 100-year monthly WMT diagnostics, per experiment pi/ mh/ lig/ lgm/ mis/sam_composites/ :pre-computed Southern Annular Mode composites fw_data/ :SAM freshwater-flux composites (regular grid)mesh/ :FESOM unstructured mesh (geometry only) Sub-directory `pi/`, `mh/`, `lig/`, `lgm/`, `mis/` always denotes the corresponding climate state. 1. climatology/<exp>/ — climatological monthly means files sst_reg.nc: sea surface temperature in degrees Celsius sss_reg.nc: sea surface salinity in psu MLD1_reg.nc: mixed layer depth in meters a_ice_reg.nc: sea ice concentration ranging from 0 to 1 age_reg.nc: ideal ocean ventilation age across 47 depth levels in years mask_surface.nc: ocean and land mask derived from three-dimensional salinity data prec_reg.nc: precipitation freshwater flux in m/s evap_reg.nc: evaporation freshwater flux in m/s snow_reg.nc: snowfall freshwater flux in m/s runoff_reg.nc: river runoff freshwater flux in m/s fw_reg.nc: net sea ice related freshwater flux in m/s echam_clim_subset.nc: eight ECHAM atmospheric variables on T63 grid covering surface fluxes and 10-meter wind data All *_reg.nc files have been bilinearly interpolated from the native FESOM unstructured mesh onto a regular 1°×1° grid (`lat` 180, `lon` 360); timedimension = 12 (calendar months). `echam_clim_subset.nc` is on the native ECHAM6 T63 Gaussian grid (`lat` 96, `lon` 192), time = 12. for echam_clim_subset.nc, only these 8 variables were extracted from the full ECHAM climatology var92: long-wave (LW) heat flux W m⁻² var95: short-wave (SW) heat flux W m⁻² var111: latent heat (LH) flux W m⁻² var120: sensible heat (SH) flux W m⁻² var165: 10 m zonal wind (u10) m s⁻¹ var166: 10 m meridional wind (v10) m s⁻¹ var180: zonal wind stress (ustr) N m⁻² var181: meridional wind stress (vstr) N m⁻² 2. wmt_100years/<exp>/ : 100-year monthly WMT diagnostics files: wmt_southern_ocean_100years_<exp>.ncwmt_ross_sea_100years_<exp>.ncwmt_weddell_sea_100years_<exp>.ncwmt_adelie_100years_<exp>.nc Each file holds 1200 monthly values (100 years × 12 months) so that the JJA-mean and its interannual ±1σ spread can be reconstructed. 3. sam_composites/ : Southern Annular Mode composites SAM is computed from JJA-mean sea-level pressure of the 100-year monthly output. High-/low-SAM years are selected with a ±1.2σ threshold about the mean. Files here are the pre-computed composites. files: sam_index_<exp>.nc (SAM JJA index time series) heatflux_sam_composite_t63_<exp>.nc (High−low SAM heat-flux composite) wmt_sam_composite_<region>_<exp>.nc (High−low SAM WMT composite) fw_data/<var>_<highsam\|lowsam>_<exp>_reg.nc (High−low SAM freshwater-flux composite)