Slot: Variable Identity (variable_identity)

The variable identity object — what physical quantity is being captured. Bound to VariableIdentity (see envar_variable). Readable rename of the profile's observation_type anatomy slot.

Tier: core

Why this slot matters

Without a standard variable identity, "tmax" in one file and "TMAX" in another cannot be recognised as the same physical quantity, and unit mix-ups (Celsius vs Fahrenheit vs Kelvin) go undetected — pooling and cross-study comparison silently break.

In plain terms

This block pins down exactly what was measured. Instead of relying on a nickname like "tmax", it uses shared vocabularies to say "daily maximum air temperature, in degrees Celsius", so any tool or researcher reads it the same way.

URI: envar:slot/variable_identity

Applicable Classes

Name	Description	Modifies Slot
EnvironmentalExposureRecord	A single environmental-exposure record sidecar: the complete metadata graph t...	no
DailyMaxTemperatureRecord	Canonical record for daily maximum 2 m air temperature (Tmax)	no
DailyMinTemperatureRecord	Canonical record for daily minimum 2 m air temperature (Tmin)	no
WetBulbGlobeTemperatureOutdoorRecord	Canonical record for outdoor WBGT under the Liljegren 2008 formulation	no
ExtremeHeatDayFlagRecord	Canonical record for a daily binary extreme-heat-day flag, defined against a ...	no

Properties

Type and Range

Property	Value
Range	VariableIdentity
Domain Of	EnvironmentalExposureRecord
Slot Group	exposure_description

Cardinality and Requirements

Property	Value
Required	Yes

Aliases

observation_type

Examples

Value
None

Identifier and Mapping Information

Annotations

property	value
tier	core
justification	Without a standard variable identity, "tmax" in one file and "TMAX" in another cannot be recognised as the same physical quantity, and unit mix-ups (Celsius vs Fahrenheit vs Kelvin) go undetected — pooling and cross-study comparison silently break.
explanation	This block pins down exactly what was measured. Instead of relying on a nickname like "tmax", it uses shared vocabularies to say "daily maximum air temperature, in degrees Celsius", so any tool or researcher reads it the same way.
covered_by	None

Schema Source

from schema: https://w3id.org/linkml/microschemas/envar

Mappings

Mapping Type	Mapped Value
self	envar:variable_identity
native	envar:variable_identity
exact	msprofile:observation_type

LinkML Source

name: variable_identity
implements:
- msprofile:observation_type
annotations:
  tier:
    tag: tier
    value: core
  justification:
    tag: justification
    value: Without a standard variable identity, "tmax" in one file and "TMAX" in
      another cannot be recognised as the same physical quantity, and unit mix-ups
      (Celsius vs Fahrenheit vs Kelvin) go undetected — pooling and cross-study comparison
      silently break.
  explanation:
    tag: explanation
    value: This block pins down exactly what was measured. Instead of relying on a
      nickname like "tmax", it uses shared vocabularies to say "daily maximum air
      temperature, in degrees Celsius", so any tool or researcher reads it the same
      way.
  covered_by:
    tag: covered_by
    annotations:
      omop_gaia:
        tag: omop_gaia
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: gaia_db variable_source.variable_name/variable_description + JSON-LD
              variableMeasured.propertyID (NERC air_temperature); unit_concept_id
              8653
          note:
            tag: note
            value: 'Gaia carries variable name, description, unit, and a CF-mirror
              propertyID, but CF cell_methods has no slot. Conservative: partial.'
      degauss:
        tag: degauss
        annotations:
          extent:
            tag: extent
            value: absent
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: Variable identity is implicit in the column header tmax with no
              CF standard name, cell methods, or unit annotation.
      amadeus:
        tag: amadeus
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: thredds_dataset.xml long_name/standard_name/description + gridmet_tmmx.cf_metadata.json
              units
          note:
            tag: note
            value: 'Amadeus carries a CF-style blob (long_name, units K), but standard_name
              is overloaded with the gridMET shortcode, not a real CF term. Conservative:
              partial.'
      cher:
        tag: cher
        annotations:
          extent:
            tag: extent
            value: partial
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: table_column_dictionary.column_tag=Value + column_unit_id (+ planned
              ontology tag)
          note:
            tag: note
            value: C-HER tags a Value column with a unit and (planned) ontology tag,
              but carries no CF standard name / cell-methods identity.
      codata:
        tag: codata
        annotations:
          extent:
            tag: extent
            value: out_of_layer
          status:
            tag: status
            value: asserted
          where:
            tag: where
            value: no column
          note:
            tag: note
            value: Variable identity is exactly the conceptual/represented layer CODATA
              EVs occupy, but as a conceptual framework it is excluded from instance-layer
              scoring.
description: The variable identity object — what physical quantity is being captured.
  Bound to VariableIdentity (see envar_variable). Readable rename of the profile's
  `observation_type` anatomy slot.
title: Variable Identity
examples:
- description: abridged — see tests/data/valid/EnvironmentalExposureRecord-tmax_ideal.yaml
    for a full instance
  object:
    variable_name: tmax
    standard_name: CF:air_temperature
    cf_cell_methods: 'time: maximum'
    units_ucum: Cel
from_schema: https://w3id.org/linkml/microschemas/envar
see_also:
- https://cfconventions.org/
- https://ucum.org/
aliases:
- observation_type
exact_mappings:
- msprofile:observation_type
rank: 1000
domain_of:
- EnvironmentalExposureRecord
slot_group: exposure_description
range: VariableIdentity
required: true
inlined: true