CMIP Inputs

Guidance on obtaining and preparing CMIP6/CMIP7 data for i7aof.

  • Variables: thetao, so, and zos.

  • Convert thetao/so to TEOS-10 ct/sa on the native grid first using i7aof.convert.cmip or the ismip7-antarctic-convert-cmip CLI, then remap to ISMIP grids with i7aof.remap.cmip or the ismip7-antarctic-remap-cmip CLI.

  • Configure paths and patterns in your .cfg files.

Tips

  • Time chunking can significantly impact performance. For CESM2-WACCM, 12-month chunks have shown ~25% speedup vs 1-month chunks. Configure via [convert_cmip] time_chunk = 12 in your model config.

  • Set I7AOF_DEBUG_TEOS10=1 to print profiling info for the TEOS-10 step if you need to troubleshoot performance.

Post-extrap vertical resampling

After running ismip7-antarctic-extrap-cmip, a conservative resampling step maps ct/sa from z_extrap to z (20 m → 60 m by default). This now uses a Zarr-first workflow that appends results by time chunk and converts once to NetCDF, significantly improving performance and reducing memory usage.

  • Configure the resampling time chunk length with [extrap_cmip] time_chunk_resample in your config.

  • Final outputs use the ismip<hres>_<dz> resolution tag (or _z suffix if the tag would be unchanged). A temporary <basename>.zarr/ folder appears during processing and is cleaned up automatically.