2.4.0b1

2.4.0b1 (24/09/2026)

Beta Release v2.4.0b1

This beta release introduces the new coordinate-validation framework for CMIP7, ESGVOC global-attribute validation ncattvalid and improved time-axis checks.

It is intended for early testing by data providers before the final 2.4.0 release.

Highlights

Coordinate validation

• Added the new coordinate-validation framework introduced in PR #81.
• Added ESGVOC-backed CMIP7 coordinate validation.
• The complete coordinate catalogue is loaded once during checker setup and reused by the coordinate checks.
• Added validation for:
  • ordinary one-dimensional coordinates;
  • scalar and auxiliary coordinates;
  • coordinate identity, dimensions, storage type, and structure;
  • coordinate attributes and requested values;
  • monotonicity and stored direction;
  • physical ranges and configured valid minimum and maximum values;
  • bounds and climatology variables;
  • bounds dimensions, shape, type, values, containment, overlap, and direction;
  • horizontal grids and grid topology;
  • latitude and longitude coordinates;
  • vertical coordinates;
  • formula terms, computed standard names, and z-factor structure;
  • text-valued auxiliary coordinates and their associations with data variables.
• Added the COORD000 to COORD012 result families:
  • COORD000: ESGVOC catalogue initialization;
  • COORD001: coordinate existence, identity, type, and structure;
  • COORD002: data-variable dimension names and order;
  • COORD003: required coordinate attributes;
  • COORD004: recommended attributes and unexpected metadata;
  • COORD004a: attributes allowed when unset;
  • COORD005: coordinate monotonicity and direction;
  • COORD006: configured valid minimum and maximum values;
  • COORD007: requested coordinate and bounds values;
  • COORD008: bounds and climatology structure and values;
  • COORD009: recommended bounds and vertex naming;
  • COORD010: coordinate and site associations;
  • COORD011: horizontal grid topology;
  • COORD012: vertical coordinates and formula terms.
• Coordinate identity and type are determined from ESGVOC rather than inferred from the file metadata.
• Missing, non-finite, and masked coordinate values are retained during validation and reported explicitly.
• A failure to initialize the ESGVOC coordinate catalogue now produces a single COORD000 result, while dependent checks are skipped cleanly.
• Improved reporting so that structural errors remain required checks while naming and metadata recommendations use the configured lower severity.
• Removed redundant CMIP7 time.units and time.bounds rules when the corresponding metadata is provided by ESGVOC.

Time-axis validation

• Fixed floating-point precision failures in TIME001, including failures observed on long 1-hour time axes.
• Improved time-squareness calculations for subdaily, daily, monthly, seasonal, annual, and multi-year frequencies.
• Added validation of regular bounds spacing and regular or climatological interval midpoints.
• Expected time bounds are now generated independently instead of trusting potentially invalid bounds from the file.
• Prevented invalid bounds from being used as the reference for subsequent time-axis checks.
• Improved the separation of responsibilities between time checks:
  • VAR005 validates that time values are strictly increasing;
  • TIME001 validates time squareness, bounds spacing, and interval midpoints;
  • TIME002 validates time-bounds dimensions, shape, and containment;
  • TIME003 validates the filename time range.
• Improved climatological time validation, including representative midpoints and coverage-derived filename labels.
• Improved filename time-range validation for:
  • climatological datasets;
  • subdaily and coarse frequencies;
  • label precision;
  • project-specific climatology suffixes.
• Improved handling of representative timestamps so that no incorrect additional half-interval is applied.
• Added support for the julian calendar.
• Added clearer and more consistent time-check reporting.

ESGVOC global-attribute validation

• ESGVOC ncattvalid is now the source of truth for supported global-attribute definitions and allowed values.
• Project TOML files retain:
  • check severity;
  • project-specific rules;
  • conditional requirements;
  • rules that are not available from ESGVOC.
• Attributes that are not currently represented by ESGVOC continue to be validated by the existing attribute suite.
• Preserved the existing ATTR001 to ATTR004 check identifiers.
• Preserved the configured high, medium, and low severity levels.
• Required and recommended wording is now derived from the configured severity.
• Improved handling and reporting of:
  • missing required attributes;
  • invalid controlled-vocabulary terms;
  • unavailable ESGVOC definitions;
  • attributes that remain governed by project-specific configuration.

CMIP7 variable metadata

• CMIP7 branded-variable lookups now use the project-specific branded_variable collection.
• Removed the CMIP7 dependency on the Universe known_branded_variable descriptor for these lookups.
• Added fallback handling for project variable metadata.
• Improved registry identifier matching.
• Improved normalization of registry metadata, including compatibility between units and the legacy cf_units field.
• Preserved compatibility with existing project-specific validation where the required metadata is not available from the registry.

Mapping and configuration fixes

• Corrected tasmax and tasmin mappings:
  • Amon.tasmax now uses tas_tmaxavg-h2m-hxy-u;
  • Amon.tasmin now uses tas_tminavg-h2m-hxy-u;
  • daily tasmax and tasmin continue to use tas_tmax-h2m-hxy-u and tas_tmin-h2m-hxy-u.
• Corrected the mrsos branded-variable mapping.
• Corrected the simass branded-variable mapping.
• Added the missing Omon.prsn mapping.
• Updated branded-variable mappings for CMIP6, CMIP6Plus, and C3S-CMIP6.
• Updated time-unit patterns and supported calendar values.
• Added compatibility with both current and legacy ESGVOC unit metadata.