The conversion from the source's native representation to the values in the companion data file, written out, e.g. Cel = K - 273.15 or K = stored × 0.1 + 220.0; Cel = K - 273.15. Required whenever native_units_ucum is declared.
Tier: conditionally_core
Why this slot matters
Twin value columns and silent container conversions are how factor-of-1.8 unit errors enter exposure analyses undetected. Once native units are declared, the bridging math is the only record of how the file's values relate to the source's — it is what makes the conversion checkable rather than trusted.
In plain terms
When the original data used different units, this spells out the exact arithmetic that turned them into the numbers in the data file — like showing your work in a calculation, so others can check it.
URI: envar:slot/unit_conversion_formula
Applicable Classes
| Name |
Description |
Modifies Slot |
| VariableIdentity |
The identity and semantics of an environmental exposure variable — what physi... |
no |
Properties
Type and Range
Cardinality and Requirements
Examples
| Value |
| K = stored * 0.1 + 220.0; Cel = K - 273.15 |
- Added after the reverse gap survey (docs/reverse-gap-survey.md, 2026-07): the Amadeus translation carried this exact math only as a YAML comment ("the schema has no slot for it"), and the GAIA scenario hand-added it as an
envar:unit_conversion PropertyValue. The comparison table in the EnVar pipeline repo lists "K→°C conversion math recorded: ❌" for every pipeline — this slot is the fix.
Annotations
| property |
value |
| tier |
conditionally_core |
| justification |
Twin value columns and silent container conversions are how factor-of-1.8 unit errors enter exposure analyses undetected. Once native units are declared, the bridging math is the only record of how the file's values relate to the source's — it is what makes the conversion checkable rather than trusted. |
| explanation |
When the original data used different units, this spells out the exact arithmetic that turned them into the numbers in the data file — like showing your work in a calculation, so others can check it. |
Schema Source
Mappings
| Mapping Type |
Mapped Value |
| self |
envar:unit_conversion_formula |
| native |
envar:unit_conversion_formula |
LinkML Source
name: unit_conversion_formula
annotations:
tier:
tag: tier
value: conditionally_core
justification:
tag: justification
value: Twin value columns and silent container conversions are how factor-of-1.8
unit errors enter exposure analyses undetected. Once native units are declared,
the bridging math is the only record of how the file's values relate to the
source's — it is what makes the conversion checkable rather than trusted.
explanation:
tag: explanation
value: When the original data used different units, this spells out the exact
arithmetic that turned them into the numbers in the data file — like showing
your work in a calculation, so others can check it.
description: The conversion from the source's native representation to the values
in the companion data file, written out, e.g. `Cel = K - 273.15` or `K = stored
× 0.1 + 220.0; Cel = K - 273.15`. Required whenever `native_units_ucum` is declared.
title: Unit Conversion Formula
comments:
- 'Added after the reverse gap survey (docs/reverse-gap-survey.md, 2026-07): the Amadeus
translation carried this exact math only as a YAML comment ("the schema has no slot
for it"), and the GAIA scenario hand-added it as an `envar:unit_conversion` PropertyValue.
The comparison table in the EnVar pipeline repo lists "K→°C conversion math recorded:
❌" for every pipeline — this slot is the fix.'
examples:
- value: K = stored * 0.1 + 220.0; Cel = K - 273.15
description: gridMET tmmx unpack-then-convert chain in the Amadeus scenario
from_schema: https://w3id.org/linkml/microschemas/envar
rank: 1000
domain_of:
- VariableIdentity
range: string