@prefix :        <http://linked.earth/ontology#> .
@prefix owl:     <http://www.w3.org/2002/07/owl#> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xml:     <http://www.w3.org/XML/1998/namespace> .
@prefix xsd:     <http://www.w3.org/2001/XMLSchema#> .
@prefix dcterms:  <http://purl.org/dc/terms/> .
@prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#> .
@prefix vann:    <http://purl.org/vocab/vann/> .

:age  a       :Time , owl:NamedIndividual ;
      rdfs:comment "The age of a sample"@en ;
      rdfs:label "Age"@en .

:palmerDroughtIndex
      a       :ClimateIndex , owl:NamedIndividual ;
      rdfs:label "Palmer Drought Index"@en ;
      owl:sameAs :palmerDroughtSeverityIndex .

:julianDay
      a       :Time , owl:NamedIndividual ;
      rdfs:label "Julian day"@en .

:northAtlanticOscillation
      a       :ClimateIndex , owl:NamedIndividual ;
      rdfs:label "North Atlantic Oscillation (NAO)"@en .

:arcticOscillation
      a       :ClimateIndex , owl:NamedIndividual ;
      rdfs:label "Arctic Oscillation (AO, AAO)"@en .

:moistureContent
      a       :Hydrology , owl:NamedIndividual ;
      rdfs:label "Moisture content"@en .

:OceanChemistry
      a       owl:Class ;
      rdfs:label "Ocean chemistry"@en ;
      rdfs:subClassOf :InferredVariable .

:AtmosphericChemistry
      a       owl:Class ;
      rdfs:label "Atmospheric chemistry"@en ;
      rdfs:subClassOf :InferredVariable .

:southernOscillationIndex
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Southern oscillation index (SOI)"@en .

:precipitationAmount
      a       :Precipitation , owl:NamedIndividual ;
      rdfs:label "Precipitation amount"@en .

:nino2
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 2"@en .

:bottomWaterTemperature
      a       :Temperature , owl:NamedIndividual ;
      rdfs:label "Bottom water temperature"@en .

:temperature
      a       :Temperature , owl:NamedIndividual ;
      rdfs:comment "Thermodynamic property which quantifies how cold or warm an object, a fluid, or a substance is."@en ;
      rdfs:label "Temperature"@en .

:oceanMixedLayerTemperature
      a       :Temperature , owl:NamedIndividual ;
      rdfs:label "Ocean mixed layer temperature"@en .

:Precipitation
      a       owl:Class ;
      rdfs:label "Precipitation"@en ;
      rdfs:subClassOf :Hydrology .

:InferredVariable
      a       owl:Class ;
      rdfs:isDefinedBy <http://linked.earth/ontology/core/1.2.0> ;
      rdfs:label "Inferred variable"@en .

:IsotopicComposition
      a       owl:Class ;
      rdfs:label "Isotopic composition"@en ;
      rdfs:subClassOf
              [ a       owl:Class ;
                owl:unionOf
                        [ a       rdf:List ;
                          rdf:first :Hydrology ;
                          rdf:rest
                                  [ a       rdf:List ;
                                    rdf:first :OceanChemistry ;
                                    rdf:rest ()
                                  ]
                        ]
              ] .

:carbonDioxideConcentration
      a       owl:NamedIndividual , :AtmosphericChemistry ;
      rdfs:label "Carbon dioxide concentration"@en .

:Temperature
      a       owl:Class ;
      rdfs:comment "Thermodynamic property allowing to quantitatively measure how warm or cold a material, fluid is."@en ;
      rdfs:label "Temperature"@en ;
      rdfs:subClassOf :InferredVariable .

:nino3_4
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 3.4"@en .

:nino1
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 1"@en .

:year
      a       :Time , owl:NamedIndividual ;
      rdfs:label "Year"@en .

:surfaceAirTemperature
      a       :Temperature , owl:NamedIndividual ;
      rdfs:label "Surface air temperature"@en .

:ClimateIndex
      a       owl:Class ;
      rdfs:label "Climate index"@en ;
      rdfs:subClassOf :InferredVariable .

:carbonateSaturation
      a       owl:NamedIndividual , :OceanChemistry ;
      rdfs:label "Carbonate saturation"@en .

:seaSurfaceTemperature
      a       :Temperature , owl:NamedIndividual ;
      rdfs:comment "The temperature close to the ocean's surface"@en ;
      rdfs:label "Sea surface temperature"@en .

:palmerDroughtSeverityIndex
      a       :ClimateIndex , :Hydrology , owl:NamedIndividual ;
      rdfs:label "Palmer Drought Severity Index (PDSI)"@en .

:salinity
      a       owl:NamedIndividual , :OceanChemistry ;
      rdfs:label "Salinity"@en .

:d180
      a       owl:NamedIndividual , :IsotopicComposition ;
      rdfs:label "d180"@en .

:Hydrology
      a       owl:Class ;
      rdfs:label "Hydrology"@en ;
      rdfs:subClassOf :InferredVariable .

:nino4
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 4"@en .

:southernAnnularMode
      a       :ClimateIndex , owl:NamedIndividual ;
      rdfs:label "Southern Annular Mode (SAM)"@en .

:dD   a       owl:NamedIndividual , :IsotopicComposition ;
      rdfs:label "DD"@en .

:freeOxygenLevels
      a       owl:NamedIndividual , :AtmosphericChemistry ;
      rdfs:label "Free oxygen levels"@en .

:Time
      a       owl:Class ;
      rdfs:label "Time"@en ;
      rdfs:subClassOf :InferredVariable .

:pH   a       owl:NamedIndividual , :OceanChemistry ;
      rdfs:label "PH"@en .

:radiocarbonAge
      a       :Time , owl:NamedIndividual ;
      rdfs:label "Radiocarbon age"@en .

:Nino1Plus2
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 1+2"@en .

:methaneConcentration
      a       owl:NamedIndividual , :AtmosphericChemistry ;
      rdfs:label "Methane concentration"@en .

:     a       owl:Ontology ;
      dcterms:contributor <http://www.isi.edu/~gil/> , <http://w3id.org/people/dgarijo> ;
      dcterms:creator <http://orcid.org/0000-0001-5920-4751> , <http://www.cefns.nau.edu/~npm4/> , <http://earth.usc.edu/~khider/> ;
      dcterms:license <http://creativecommons.org/licenses/by/2.0/> ;
      dcterms:title "The Inferred Variable Ontology"@en ;
      vann:preferredNamespacePrefix
              "le" ;
      vann:preferredNamespaceUri
              "http://linked.earth/ontology#" ;
      owl:versionIRI <http://linked.earth/ontology/inferredVariable/1.0.0> ;
      owl:versionInfo "1.0.0"@en .

:CarbonateIonConcentration
      a       owl:NamedIndividual , :OceanChemistry ;
      rdfs:label "Carbonate ion concentration"@en .

:deuteriumExcess
      a       owl:NamedIndividual , :IsotopicComposition ;
      rdfs:label "Deuterium excess (excessD)"@en .

:ElNinoIndex
      a       owl:Class ;
      rdfs:subClassOf :ClimateIndex .

:nitrousOxideConcentration
      a       owl:NamedIndividual , :AtmosphericChemistry ;
      rdfs:label "Nitrous oxide concentration"@en .

:atlanticMultiDecadalOscillation
      a       :ClimateIndex , owl:NamedIndividual ;
      rdfs:label "Atlantic Multi-decadal Oscillation (AMO)"@en .

:nino3
      a       :ElNinoIndex , owl:NamedIndividual ;
      rdfs:label "Nino 3"@en .