Climatology Workflows

This page covers the climatology-only pipeline. No CMIP inputs are required. You can run the full end-to-end processing for an observational climatology in four steps: Remap → Extrapolate → Thermal Forcing → Back‑convert.

Source

The climatologies were provided by Zhou and collaborators, and are similar to (but updated from) the publicly available dataset Zhou et al. (2024).

Supported Climatologies (prefer v2: 06_nov)

Select a climatology with --clim <clim_name> on the CLIs. Each clim_name corresponds to a config file under i7aof/clim/*.cfg that defines variable/dimension names and the relative input path under your input base directory.

Recommended (v2, 06_nov):

  • zhou_annual_06_nov → Updated_TS_Climatology/OI_Climatology_v2/OI_Climatology.nc

  • zhou_summer_06_nov → Updated_TS_Climatology/OI_Climatology_v2/OI_summer_Climatology.nc

  • zhou_2000_annual_06_nov → Updated_TS_Climatology/OI_Climatology_v2/OI_2000_Climatology.nc

Also available (earlier 30_sep set):

  • zhou_annual_30_sep → Updated_TS_Climatology/OI_Climatology.nc

  • zhou_summer_30_sep → Updated_TS_Climatology/OI_summer_Climatology.nc

  • zhou_2000_annual_30_sep → Updated_TS_Climatology/OI_2000_Climatology.nc

Variables provided: conservative temperature ct and absolute salinity sa, with mean‑square‑error fields ct_mse and sa_mse in v2. The raw vertical coordinate is pressure (dbar) and is converted to height (meters, positive up) during preprocessing.

Remap (Step 3a)

Two stages are performed: (1) vertical preparation to the ISMIP z_extrap levels with masking and normalization, then (2) horizontal remapping to the ISMIP grid (method set by [remap] method).

CLI:

ismip7-antarctic-remap-clim \
  --clim zhou_annual_06_nov \
  --config my.cfg

Job script: example_job_scripts/03_remap/job_script_remap_clim.bash

Outputs:

<workdir>/intermediate/03_remap/climatology/<clim_name>/*_ismip<res>.nc

Extrapolate + Resample (Step 4a)

We fill spatial gaps horizontally then vertically (Fortran routines). A dummy singleton time dimension is added for processing and removed in the final outputs. After extrapolation, we conservatively resample from z_extrap to z levels (e.g., 20 m → 60 m).

CLI:

ismip7-antarctic-extrap-clim \
  --clim zhou_annual_06_nov \
  --config my.cfg

Job script: example_job_scripts/04_extrap/job_script_extrap_clim.bash

Outputs:

<workdir>/intermediate/04_extrap/climatology/<clim_name>/*_{ct,sa}_extrap.nc
<workdir>/intermediate/04_extrap/climatology/<clim_name>/*_z.nc

Dimension order for final climatology products is (z, y, x) (no time).

Note: Remap outputs are (z_extrap, y, x). During extrapolation a dummy time is inserted to form (time, z_extrap, y, x) for the Fortran step.

Thermal Forcing (Step 6b)

Compute TF from CT/SA derived from the climatology.

CLI:

ismip7-antarctic-clim-ct-sa-to-tf \
	--clim zhou_annual_06_nov \
	--config my.cfg

Job script: example_job_scripts/06_ct_sa_to_tf/job_script_tf_clim.bash

Outputs:

<workdir>/intermediate/04_extrap/climatology/<clim_name>/*_tf_extrap.nc

Back‑convert to thetao/so (Step 8b)

Provide static thetao/so fields derived from climatology CT/SA.

CLI:

ismip7-antarctic-clim-ct-sa-to-thetao-so \
	--clim zhou_annual_06_nov \
	--config my.cfg

Job script: example_job_scripts/08_ct_sa_to_thetao_so/job_script_thetao_clim.bash

Outputs:

<workdir>/intermediate/04_extrap/climatology/<clim_name>/*_{thetao,so}_extrap.nc

Final published climatology outputs (Obs) are written to:

/final/AIS/obs/ocean/climatology/<clim_name>///AIS_obs_ocean_climatology<clim_name>.nc

Configuration Keys

Each i7aof/clim/zhou_*.cfg file defines, for its source:

[climatology]
lat_var, lon_var, lat_dim, lon_dim
lev_var, lev_dim (pressure) -> converted to lev (meters)
filename (relative path under input base dir)
ct_var, sa_var (and optionally ct_mse_var, sa_mse_var)

You can override paths and settings via a user config passed with --config.

Notes and Tips

  • Prefer the 06_nov (v2) climatologies; they include MSE variables and updated metadata. The 30_sep set remains available for continuity.

  • For heavy remapping, tune chunk sizes in your config to match your system.

Python API

Minimal climatology-only example:

from i7aof.remap.clim import remap_climatology
from i7aof.extrap.clim import extrap_climatology
from i7aof.convert.ct_sa_to_tf import clim_ct_sa_to_tf
from i7aof.convert.ct_sa_to_thetao_so import clim_ct_sa_to_thetao_so

clim = 'zhou_annual_06_nov'
cfg = 'my.cfg'

remap_climatology(clim, user_config_filename=cfg)
extrap_climatology(clim, user_config_filename=cfg)
clim_ct_sa_to_tf(clim, user_config_filename=cfg)
clim_ct_sa_to_thetao_so(clim, user_config_filename=cfg)

See also End‑to‑End Workflows for how the climatology ties into the full CMIP pipeline.