Element Description

The Science Keywords element allows relevant Earth science keywords to be associated with a dataset to better enable data search and discovery. The Science Keywords are chosen from a controlled keyword hierarchy maintained in the Keyword Management System (KMS). A list of valid Science Keywords can be found here: https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/sciencekeywords?format=csv.

(It is important to note that the "EARTH SCIENCE SERVICES" keywords included at the top of the list in the csv file should not be used as Science Keywords. Valid Science Keywords start with the "EARTH SCIENCE" Category). 

Best Practices

Science keywords are important for the precise search and retrieval of data and should accurately represent the dataset being described. As a rule of thumb, science keywords should represent the scientific parameters being provided in the data as well as any broader conceptual terms that may aid in describing the data. At a minimum, one science keyword hierarchy must be provided, and this hierarchy must go down to the 'Term' level of detail. The 'Detailed Variable' element is the only science keyword element that is not controlled by the KMS. The 'Detailed Variable' keyword should only be used if there is a very specific parameter provided in the data which is not adequately described by keywords in the KMS. If a particular science keyword is missing from the KMS, it is possible to put in a request to have it added. The KMS is managed by the Global Change Master Directory (GCMD) and new keyword requests may be made through the GCMD Keywords Community Forum.

All positions in the science keyword hierarchy must be populated until the desired level of detail is reached. Skipping or leaving blank a position in the keyword hierarchy will render the keyword invalid. The only exception to this is the 'Detailed Variable' element; a Detailed Variable keyword may be provided as long as it is preceded by the required Category, Topic, and Term keywords. Science keywords are not case sensitive.  

        

Examples:

ScienceKeywords/Category: "EARTH SCIENCE"

ScienceKeywords/Topic: "ATMOSPHERE"

ScienceKeywords/Term: "CLOUDS"

ScienceKeywords/VariableLevel1: "TROPOSPHERIC/LOW LEVEL CLOUDS (OBSERVED/ANALYZED)"

ScienceKeywords/VariableLevel2: "STRATOCUMULUS"

ScienceKeywords/VariableLevel3: "STRATOCUMULUS CUMILIFORMIS"

ScienceKeywords/DetailedVariable: "STRATOCUMULUS VESPERALIS"


ScienceKeywords/Category: "EARTH SCIENCE"

ScienceKeywords/Topic: "BIOSPHERE"

ScienceKeywords/Term: "ECOLOGICAL DYNAMICS"

ScienceKeywords/VariableLevel1: "FIRE ECOLOGY"

ScienceKeywords/VariableLevel2: "FIRE MODELS"


Element Specification

One Science Keyword is required and more Science Keywords may be provided (Cardinality: 1..*).  For every science keyword that is provided the sub elements of Category, Topic, and Term are required.

ModelElementTypeUsable Valid ValuesConstraintsRequired?Cardinality
UMM-CScienceKeywords/CategoryStringScience Category Keywords

KMS controlled

Yes1
UMM-CScienceKeywords/TopicStringScience Topic KeywordsKMS controlled
Yes1
UMM-CScienceKeywords/TermStringScience Term KeywordsKMS controlledYes1
UMM-CScienceKeywords/VariableLevel1StringScience Variable_Level_1 KeywordsKMS controlledNo0..1
UMM-CScienceKeywords/VariableLevel2String

Science Variable_Level_2 Keywords

KMS controlledNo0..1
UMM-CScienceKeywords/VariableLevel3String

Science Variable_Level_3 Keywords

KMS controlledNo0..1
UMM-CScienceKeywords/DetailedVariableString
1 - 80 characters (Uncontrolled/Free-Text)No0..1


Metadata Validation and QA/QC

All metadata entering the CMR goes through the below process to ensure metadata quality requirements are met. All records undergo CMR validation before entering the system. The process of QA/QC is slightly different for NASA and non-NASA data providers. Non-NASA providers include interagency and international data providers and are referred to as the International Directory Network (IDN).

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Please see the expandable sections below for flowchart details.


  • Manual Review
    • Identify errors, discrepancies, or omissions.
    • Verify that all pertinent keywords have been applied.
    • Verify that existing facets and other controlled keyword values are consistent and suitable for the data.
  • Automated Review
    • Check that the field has been populated.
    • Check that the field is populated with a valid value from KMS.
    • Check that the field value is not a duplicate.
    • Check that the 'Detailed_Variable' field length is not greater than 80 characters.
  • This element is required and at least 1 science keyword must exist.
  • For every science keyword the sub elements of Category, Topic, and Term must exist.
  • All science keyword sub-elements except for DetailedVariable must be valid according to the keyword management system. Currently the CMR issues a warning if this constraint is violated.

ARC Priority Matrix

Priority CategorizationJustification

Red = High Priority Finding

This element is categorized as highest priority when:

  • No Science Keywords are provided.
  • A Science Keyword does not align with the KMS.
    • The Science Keyword does not exist in the KMS.
    • A keyword(s) is missing from the keyword hierarchy.
    • A keyword(s) is placed in the incorrect position of the keyword hierarchy (e.g. a Variable Level 2 keyword is placed in the Variable Level 1 field).
  • A Science Keyword provided is not appropriate for the dataset.

Yellow = Medium Priority Finding

This element is categorized as medium priority when:

  • A recommendation is made to add a relevant Science Keyword to the metadata.
  • A recommendation is made to add to an existing keyword in the metadata (i.e. to extend a keyword hierarchy down to a more detailed level).

Blue = Low Priority Finding

Not Applicable

Green = No Findings/Issues

The element is provided and follows all applicable criteria specified in the best practices section above.

ARC Automated Checks

ARC uses the pyQuARC library for automated metadata checks. Please see the pyQuARC GitHub for more information. 

Dialect Mappings

DIF 9 (Note: DIF-9 is being phased out and will no longer be supported after 2018)

DIF 10

Science_Keywords are required. An unlimited amount of Science Keywords may be provided (Cardinality: 1..*)

UMM-C ElementDIF 10 PathTypeConstraintsRequired in DIF 10?CardinalityNotes
ScienceKeywords/Category

Science_Keywords/Category

String

KMS controlled

Yes

1

The category keyword will always be "EARTH SCIENCE"

ScienceKeywords/TopicScience_Keywords/Topic
String

KMS controlled

Yes1
ScienceKeywords/TermScience_Keywords/TermString

KMS controlled

Yes1
ScienceKeywords/VariableLevel1Science_Keywords/Variable_Level_1StringKMS controlledNo0..1
ScienceKeywords/VariableLevel2Science_Keywords/Variable_Level_2StringKMS controlledNo0..1
ScienceKeywords/VariableLevel3Science_Keywords/Variable_Level_3StringKMS controlledNo0..1
ScienceKeywords/DetailedVariableScience_Keywords/Detailed_VariableString1 - 80 characters (Uncontrolled/Free-Text)No0..1


Example Mapping

DIF 10

<Science_Keywords>
  <Category>EARTH SCIENCE</Category>
  <Topic>BIOSPHERE</Topic>
  <Term>VEGETATION</Term>
  <Variable_Level_1>VEGETATION INDEX</Variable_Level_1>
  <Variable_Level_2>NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)</Variable_Level_2>
  <Detailed_Variable>0.9 DENSITY</Detailed_Variable>
</Science_Keywords>
<Science_Keywords>
  <Category>EARTH SCIENCE</Category>
  <Topic>BIOSPHERE</Topic>
  <Term>VEGETATION</Term>
  <Variable_Level_1>EVERGREEN VEGETATION</Variable_Level_1>
</Science_Keywords>

UMM

ScienceKeywords: [
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "VEGETATION INDEX"
    VariableLevel2: "NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)"
    DetailedVariable: "0.9 DENSITY"
  },
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "EVERGREEN VEGETATION"
  }
],

ECHO 10

Science Keywords are required. An unlimited amount of Science Keywords may be provided (Cardinality: 1..*)

UMM-C ElementECHO 10 PathTypeConstraintsRequired in ECHO10?CardinalityNotes
ScienceKeywords/Category/Collection/ScienceKeywords/ScienceKeyword/CategoryKeywordString

KMS controlled

Yes1The category keyword will always be "EARTH SCIENCE"
ScienceKeywords/Topic/Collection/ScienceKeywords/ScienceKeyword/TopicKeywordString

KMS controlled

Yes1
ScienceKeywords/Term/Collection/ScienceKeywords/ScienceKeyword/TermKeywordStringKMS controlledYes1
ScienceKeywords/VariableLevel1/Collection/ScienceKeywords/ScienceKeyword/VariableLevel1Keyword/ValueStringKMS controlledNo0..1
ScienceKeywords/VariableLevel2/Collection/ScienceKeywords/ScienceKeyword/VariableLevel1Keyword/VariableLevel2Keyword/ValueStringKMS controlledNo0..1
ScienceKeywords/VariableLevel3/Collection/ScienceKeywords/ScienceKeyword/VariableLevel1Keyword/VariableLevel2Keyword/VariableLevel3Keyword/ValueStringKMS controlledNo0..1
ScienceKeywords/DetailedVariable/Collection/ScienceKeywords/ScienceKeyword/DetailedVariableKeywordStringUncontrolled (Free-Text)No0..1


Example Mapping

ECHO 10

<ScienceKeyword>
  <CategoryKeyword>EARTH SCIENCE</CategoryKeyword> 
  <TopicKeyword>BIOSPHERE</TopicKeyword> 
  <TermKeyword>VEGETATION</TermKeyword> 
  <VariableLevel1Keyword>
    <Value>VEGETATION INDEX</Value>
      <VariableLevel2Keyword>
        <Value>NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)</Value>
      </VariableLevel2Keyword>
  </VariableLevel1Keyword>
  <DetailedVariableKeyword>0.9 DENSITY</DetailedVariableKeyword>
</ScienceKeyword>
<ScienceKeyword>
  <CategoryKeyword>EARTH SCIENCE</CategoryKeyword> 
  <TopicKeyword>BIOSPHERE</TopicKeyword> 
  <TermKeyword>VEGETATION</TermKeyword> 
  <VariableLevel1Keyword>
    <Value>EVERGREEN VEGETATION</Value>
  </VariableLevel1Keyword>
</ScienceKeyword>

UMM

ScienceKeywords: [
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "VEGETATION INDEX"
    VariableLevel2: "NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)"
    DetailedVariable: "0.9 DENSITY"
  },
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "EVERGREEN VEGETATION"
  }
],



ISO 19115-2 MENDS

Science Keywords are required. An unlimited amount of Science Keywords may be provided (Cardinality: 1..*)

UMM-C Element

ISO 19115-2 MENDS Path

TypeNotes

ScienceKeywords/Category

ScienceKeywords/Topic

ScienceKeywords/Term

ScienceKeywords/VariableLevel1

ScienceKeywords/VariableLevel2

ScienceKeywords/VariableLevel3

ScienceKeywords/DetailedVariable

/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords/gmd:MD_Keywords/ gmd:keyword/gco:CharacterString  (list each value of the keyword hierarchy delimited by &gt; )

String


KMS controlled. This is where the entire keyword hierarchy should be listed. Each keyword in the hierarchy must be separated by "&gt;". If any keyword is missing and there exists a keyword later in the hierarchy (such as DetailedLocation), use NONE to fill in the values in between. The CMR will not translate the NONE values they are only used to place each keyword in its correct space in the hierarchy.



/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords/gmd:MD_Keywords/ gmd:keyword/gmd:type/MD_KeywordTypeCode[@codeListValue="theme"]
Codelist

codeList=https://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode

Select the value "theme" from the codelist. This codelist value does not directly map to a UMM element; choosing "theme" indicates to CMR that the Science Keywords should be mapped.



Example Mapping

ISO 19115-2 MENDS

<gmi:MI_Metadata>
  ...
  <gmd:identificationInfo>
    <gmd:MD_DataIdentification>
      <gmd:descriptiveKeywords>
        <gmd:MD_Keywords>
          <gmd:keyword>
            <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;VEGETATION INDEX&gt;NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)&gt;NONE&gt;0.9 DENSITY</CharacterString>
          </gmd:keyword>
          <gmd:keyword>
            <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;EVERGREEN VEGETATION</CharacterString>
          </gmd:keyword>
          <gmd:type>
            <gmd:MD_KeywordTypeCode codeList="https://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="theme">theme</gmd:MD_KeywordTypeCode>
          </gmd:type>
        </gmd:MD_Keywords> 
      </gmd:descriptiveKeywords>
      ...

UMM

ScienceKeywords: [
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "VEGETATION INDEX"
    VariableLevel2: "NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)"
    DetailedVariable: "0.9 DENSITY"
  },
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "EVERGREEN VEGETATION"
  }
],



ISO 19115-2 SMAP

Science Keywords are required. An unlimited amount of Science Keywords may be provided (Cardinality: 1..*)

UMM-C Element

ISO 19115-2 SMAP Path

TypeNotes

ScienceKeywords/Category

ScienceKeywords/Topic

ScienceKeywords/Term

ScienceKeywords/VariableLevel1

ScienceKeywords/VariableLevel2

ScienceKeywords/VariableLevel3

ScienceKeywords/DetailedVariable

/gmd:DS_Series/gmd:seriesMetadata/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords/ gmd:MD_Keywords/gmd:keyword/gco:CharacterString  (list each value of the keyword hierarchy delimited by &gt; )

StringKMS controlled. This is where the entire keyword hierarchy should be listed. Each keyword in the hierarchy must be separated by "&gt;". If any keyword is missing and there exists a keyword later in the hierarchy (such as DetailedLocation), use NONE to fill in the values in between. The CMR will not translate the NONE values they are only used to place each keyword in its correct space in the hierarchy.

/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords/gmd:MD_Keywords/gmd:keyword/ gmd:type/MD_KeywordTypeCode[@codeListValue="theme"]Codelist

codeList=https://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode

Select the value "theme" from the codelist. This codelist value does not directly map to a UMM element; choosing "theme" indicates to CMR that the Science Keywords should be mapped.


Example Mapping

ISO 19115-2 SMAP

<gmd:DS_Series>
 <gmd:seriesMetadata>
  <gmi:MI_Metadata>
    ...
    <gmd:identificationInfo>
      <gmd:MD_DataIdentification>
        <gmd:descriptiveKeywords>
          <gmd:MD_Keywords>
            <gmd:keyword>
              <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;VEGETATION INDEX&gt;NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)&gt;NONE&gt;0.9 DENSITY</CharacterString>
            </gmd:keyword>
            <gmd:keyword>
              <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;EVERGREEN VEGETATION</CharacterString>
            </gmd:keyword>
            <gmd:type>
              <gmd:MD_KeywordTypeCode codeList="https://cdn.earthdata.nasa.gov/iso/resources/Codelist/gmxCodelists.xml#MD_KeywordTypeCode" codeListValue="theme">theme</gmd:MD_KeywordTypeCode>
            </gmd:type>
          </gmd:MD_Keywords> 
        </gmd:descriptiveKeywords>
        ...

UMM

ScienceKeywords: [
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "VEGETATION INDEX"
    VariableLevel2: "NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)"
    DetailedVariable: "0.9 DENSITY"
  },
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "EVERGREEN VEGETATION"
  }
],



UMM Migration

None

Future Mappings

ISO 19115-1

Science Keywords are required. An unlimited amount of Science Keywords may be provided (Cardinality: 1..*)

UMM-C Element

ISO 19115-1 Path

TypeNotes

ScienceKeywords/Category

ScienceKeywords/Topic

ScienceKeywords/Term

ScienceKeywords/VariableLevel1

ScienceKeywords/VariableLevel2

ScienceKeywords/VariableLevel3

ScienceKeywords/DetailedVariable

/mdb:MD_Metadata/mdb:identificationInfo/mri:MD_DataIdentification/mri:descriptiveKeywords/

mri:MD_Keywords/mri:keyword/gco:CharacterString

(list each value of the keyword hierarchy delimited by &gt; )

StringKMS controlled. This is where the entire keyword hierarchy should be listed. Each keyword in the hierarchy must be separated by "&gt;". If any keyword is missing and there exists a keyword later in the hierarchy (such as DetailedLocation), use NONE to fill in the values in between. The CMR will not translate the NONE values they are only used to place each keyword in its correct space in the hierarchy.

/mdb:MD_Metadata/mdb:identificationInfo/mri:MD_DataIdentification/mri:descriptiveKeywords/

mri:MD_Keywords/mri:keyword/mri:type/mri:MD_KeywordTypeCode[@codeListValue="theme"]

Codelist

codeList=http://standards.iso.org/iso/19115/resources/Codelist/cat/codelists.xml#MD_KeywordTypeCode

Select the value "theme" from the codelist. This codelist value does not directly map to a UMM element; choosing "theme" indicates to CMR that the Science Keywords should be mapped.

Example Mapping

ISO 19115-1

<mdb:MD_Metadata>
  ...    
    <mdb:identificationInfo>
        <mri:MD_DataIdentification>

            <mri:descriptiveKeywords>
                <mri:MD_Keywords>
                    <mri:keyword>
                        <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;VEGETATION INDEX&gt;NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)&gt;NONE&gt;0.9 DENSITY</gco:CharacterString>
                    </mri:keyword>
                    <mri:keyword>
                        <gco:CharacterString>EARTH SCIENCE&gt;BIOSPHERE&gt;VEGETATION&gt;EVERGREEN VEGETATION</gco:CharacterString>
                    </mri:keyword>
                    <mri:type>
                        <mri:MD_KeywordTypeCode
                            codeList="http://standards.iso.org/iso/19115/resources/Codelist/cat/codelists.xml#MD_KeywordTypeCode"
                            codeListValue="MD_KeywordTypeCode_theme">theme</mri:MD_KeywordTypeCode>
                    </mri:type>
                </mri:MD_Keywords>
            </mri:descriptiveKeywords>    
            ...

UMM

ScienceKeywords: [
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "VEGETATION INDEX"
    VariableLevel2: "NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI)"
    DetailedVariable: "0.9 DENSITY"
  },
  {
    Category: "EARTH SCIENCE",
    Topic: "BIOSPHERE",
    Term: "VEGETATION",
    VariableLevel1: "EVERGREEN VEGETATION"
  }
],

History

UMM Versioning

VersionDateWhat Changed
1.15.512/3/2020No changes were made for Science Keywords during the transition from version 1.15.4 to 1.15.5
1.15.49/18/2020No changes were made for Science Keywords during the transition from version 1.15.3 to 1.15.4
1.15.37/1/2020No changes were made for Science Keywords during the transition from version 1.15.2 to 1.15.3
1.15.25/20/2020No changes were made for Science Keywords during the transition from version 1.15.1 to 1.15.2
1.15.13/25/2020No changes were made for Science Keywords during the transition from version 1.15.0 to 1.15.1
1.15.02/26/2020No changes were made for Science Keywords during the transition from version 1.14.0 to 1.15.0
1.14.010/21/2019No changes were made for Science Keywords during the transition from version 1.13.0 to 1.14.0
1.13.004/11/2019No changes were made for Science Keywords during the transition from version 1.12.0 to 1.13.0
1.12.001/22/2019No changes were made for Science Keywords during the transition from version 1.11.0 to 1.12.0.
1.11.011/28/2018No changes were made for Science Keywords during the transition from version 1.10.0 to 1.11.0.
1.10.005/02/2018No changes were made for Science Keywords during the transition from version 1.9.0 to 1.10.0.

ARC Documentation

VersionDateWhat ChangedAuthor
1.005/04/2018Recommendations/priority matrix transferred from internal ARC documentation to wiki space

Jeanne' le Roux

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3 Comments

  1. Alicia Scott

    Under "Example Mappings" section: I've noticed in the UMM examples that in some cases grouped information ends with a closing bracket followed by a comma, while in other cases, the group ends with just a closing bracket. Is this  a typo or is there some logic as to when a "bracket" is used vs "bracket, comma" to close out a group? An example of just a bracket is found under 'data centers'. It follows a similar structure as 'scienceKeywords' but closes differently. I have a similar question about the use of quotation marks. That also seems inconsistent in the examples.

    1. Jeanne' le Roux

      Hi Alicia - sorry for the delayed response. I've taken an action to go back through the examples to make sure they are displaying correctly. I think this is probably a typo - intermediate brackets do not always have a comma at the end, but the final bracket that closes the group should have a comma if there is another group that comes after it. There is some logic as to how this displays - since we are only showing snippets of metadata there have probably been some inconsistencies, since whether there is a comma or not depends on what comes before or after the snippet.   


      1. Alicia Scott

         Thanks, Jeanne'. I wasn't familiar with json so in converting our files, was tripping up on syntactical inconsistencies vs. CMR rules.