René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[BUG] Ocean variables missing time_bnds, failing CMIP6 compliance check (ATTR004/VAR004)","articleBody":"## Summary\n\nAfter CMORisation, all ocean variables (Omon + Oyr) produce output files whose\n`time` coordinate carries the attribute `bounds = \"time_bounds\"`, yet no\n`time_bounds` (or `time_bnds`) variable exists in the file. The compliance-checker\ntherefore reports a **HIGH**-severity error `ATTR004/VAR004`: the variable\nreferenced by `time:bounds` does not exist in the file.\n\n## Affected scope\n\n13 files affected (all Omon + Oyr variables):\n\n| Table | Variables |\n|-------|-----------|\n| Omon  | intpp, mlotst, so, thetao, tos, uo, vo, zos |\n| Oyr   | detoc, dissic, no3, o2, talk |\n\nAtmosphere (Amon) variables are unaffected — they follow a separate, already-working\ncode path.\n\n## Root cause\n\nThree compounding issues:\n\n1. **Naming mismatch**: the raw MOM model files contain a `time_bounds(time, nv)`\n   variable with `time:bounds = \"time_bounds\"`. The code, however, expects the\n   CMOR-convention name `time_bnds` (`_get_required_bounds_variables` builds the\n   name as `input_dim + \"_bnds\"`).\n\n2. **Dropped during loading**: `_preprocess` in `load_dataset` keeps only\n   `required_vars \u0026 ds.data_vars`. `required_vars` contains `time_bnds`, while the\n   file has `time_bounds`, so the raw `time_bounds` is silently dropped — yet the\n   `bounds = \"time_bounds\"` attribute on the `time` coordinate is preserved and\n   written to the output file.\n\n3. **Bounds calculation disabled**: in `ocean.py` the call\n   `calculate_missing_bounds_variables(required_bounds)` was double-commented out,\n   and the method was defined only on `Atmosphere_CMORiser` — `Ocean_CMORiser` did\n   not have it at all.\n\nNet result: the output file has a dangling `time:bounds` attribute with no\ncorresponding bounds variable.\n\n## Relevant code locations\n\n- `src/access_moppy/ocean.py` — the commented-out bounds calculation call\n- `src/access_moppy/atmosphere.py` — `calculate_missing_bounds_variables` (originally defined only here)\n- `src/access_moppy/base.py` — `load_dataset` / `_preprocess`\n- `src/access_moppy/vocabulary_processors.py` — `_get_required_bounds_variables`\n\n## Expected behaviour\n\nOcean output files should contain a `time_bnds(time, bnds)` variable with\n`time:bounds = \"time_bnds\"`, and `bnds` should be a pure dimension with no index\nvalues — consistent with atmosphere output and passing the compliance check.\n","author":{"url":"https://github.com/rhaegar325","@type":"Person","name":"rhaegar325"},"datePublished":"2026-06-23T06:21:34.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/454/ACCESS-MOPPy/issues/454"}