Here you can find a pointer to the main concepts and ontologies in the Linked Earth specification.
The Linked Earth specification is divided in several documents to facilitate its navigation.
The following table contains the pointers to the Linked Earth ontologies:
| Ontology | Serialization | Version | License | Language | Description |
|---|---|---|---|---|---|
| The LiPD Ontology | TURTLE | 1.2.0 | BY/2.0 | en | The LiPD Ontology aims to provide a common vocabulary for annotating paleoclimatology data |
| The Proxy Archive Ontology | TURTLE | 1.0.0 | BY/2.0 | en | The Proxy Archive Ontology defines different types of proxy archives that we can find in a paleo climate dataset. |
| The Proxy Observation Ontology | TURTLE | 1.0.0 | BY/2.0 | en | The Proxy Observation Type Ontology defines different types of proxy observations that we can find in a paleo climate dataset. |
| The Proxy Sensor Ontology | TURTLE | 1.0.0 | BY/2.0 | en | The Proxy Sensor Ontology defines different types of proxy sensors that we can find in a paleo climate dataset. |
| The Instrument Ontology | TURTLE | 1.0.0 | BY/2.0 | en | The Instrument Ontology defines the different types of instruments that can be used to measure in a paleo climate dataset. |
| Inferred Variable Ontology | TURTLE | 1.0.0 | BY/2.0 | en | Inferred Variable Ontology describes a taxonomy of the most common types of inferred variables that can be found in a dataset. |
Alternatively, you can access programatically with the following commands:
curl -sH "Accept: text/turtle" -L http://linked.earth/ontology#curl -sH "Accept: application/rdf+xml" -L http://linked.earth/ontology#To suggest changes to a term in the core ontology, start a discussion on its wiki page (all terms and properties have associated wiki pages). Once a community consensus has been reached, use this form to contact the Editorial Board about the change.
Here you can find a list of the main concepts and relationships in the Linked Earth Documents, sorted in alphabetical order.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | R | S | T | U | V | W | X | Y | Z |
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
The age of a sample
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Answers the question: Who wrote (i.e., created) the resource, such as a Publication?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Sensor Ontology
Answers the question: In which book was the resource published?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: What calibration process was used to relate the InferredVariable to the MeasuredVariable?
Defined in: The LiPD Ontology
Metadata about how the variable was calibrated to reflect an environmental variable
Defined in: The LiPD Ontology
Answers the question: In what Reference(s) is the Calibration described/justified?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Sensor Ontology
The data, metadata, and Model that describe the set of Variables used to relate depth/position to time (chronological information)
Defined in: The LiPD Ontology
DataTable containing Variables pertaining to chronological information
Defined in: The LiPD Ontology
Model used to derive a time (or age) axis from the ChronDataModel
Defined in: The LiPD Ontology
Answers the question: What is the ChronModel for the ChronData or ProxySystem under consideration?
Defined in: The LiPD Ontology
The combination of ProxyArchive, ProxySensor, and ProxyObservations pertaining to chronological information. For instance, measurements of radiocarbon on foraminiferal shells would have a ChronProxySystem consisting of ProxyArchive: marine sediment, ProxySensor: Foraminifera, ProxyObservations: Radiocarbon. (ref: Evans et al. [2013])
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Sensor Ontology
Answers the question: Where (in the world) was the data in the Dataset collected? Refers to the location of the ProxyArchive
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
A curated aggregation of datasets
Defined in: The LiPD Ontology
Answers the question: How should someone cite the compilation?
Defined in: The LiPD Ontology
Answers the question: At what date was the Compilation created?
Defined in: The LiPD Ontology
Answers the question: What is the version of the Compilation?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: Who contributed the resource? A contributor may be the same as the authors of the resource or different. For instance, in the case of a legacy dataset, a Linked Earth member may contribute a previously-published dataset that he/she may not have authored
Defined in: The LiPD Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Oxygen has three naturally-occuring stable isotopes: 16O, 17O, 18O, with 16O being the most abundant (99.762%). Two international reference standards are used to report variations in oxygen isotope standards: PDB and SMOW. The use of the PDB standard in reporting oxygen isotope composition is restricted to carbonates of low-temperature origins (e.g., oceanic, lacustrine ). The conversion between SMOW and PDB scales is given by: \delta^{18}O_{SMOW} = 1.03091 (\delta^{18}O_{PDB}) +30.91 ?18O may be measured on the shells of foraminifera
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
An aggregation of DataTables and Models with their supporting paleoenvironmental and/or chronological information
Defined in: The LiPD Ontology
A structured collection of related information, including -but not limited to -measured and/or modelled geograhical, chronological, and environmental data
Defined in: The LiPD Ontology
Sentence indicating how a dataset should be cited
Defined in: The LiPD Ontology
Answers the question: At what date was the Dataset created?
Defined in: The LiPD Ontology
License associated to a dataset
Defined in: The LiPD Ontology
Answers the question: What is the version of the Dataset? It should follow the x.y.z notation where x refers to changes in metadata and data following a publication (for instance, the creation of a new age model using a different code), y refers to changes to the data following a publication (for instance, adding data further back in time without changing the model underlying the interpretation), and z refers to changes not associated with a publication (for instance, typos).
Defined in: The LiPD Ontology
A set of Variables organized in columns
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: What additional details would you give about the resource?
Defined in: The LiPD Ontology
Answers the "of what" question for an Interpretation. For intance, sea surface in sea surface temperature.
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
DataTable containing the probability distribution of a single value of a Variable. Output of a Model
Defined in: The LiPD Ontology
Answers the question: In which DistributionTable is the Model output found?
Defined in: The LiPD Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Inferred Variable Ontology
Answers the question: What is the email address of the Person?
Defined in: The LiPD Ontology
Defined in: The Instrument Ontology
DataTable constaining many possible series of how the Variable is modeled. Output of a Model
Defined in: The LiPD Ontology
Answers the question: In which EnsembleTable is the Model output found?
Defined in: The LiPD Ontology
Answers the question: What is the mathematical formulation of the Model?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Because of their population size, foraminifera produce a significant amount of oceanic carbonate, making them a valuable source of paleoceanographic information. The following parameters are used in paleoceanographic applications: * Faunal Assemblage * Geochemical measurements: * Isotopes * Stable oxygen isotopes * Stable carbon isotopes * Radiocarbon * Trace Elements
Defined in: The Proxy Sensor Ontology
Answers the question: In which MeasurementTable are the Variables found?
Defined in: The LiPD Ontology
Answers the question: In which DataTable can the information/data be found?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Answers the question: What was the Funding source for the Dataset?
Defined in: The LiPD Ontology
Source of monetary support underlying the collection/creation/analysis/curation of the Dataset
Defined in: The LiPD Ontology
Answers the question: Which entity was the Dataset fundedBy?
Defined in: The LiPD Ontology
Answers the question: Which nation funded the Dataset?
Defined in: The LiPD Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Answers the question: which model was used to generated this data table?
Defined in: The LiPD Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: What is the unique identifier associated with the Funding for the Dataset?
Defined in: The LiPD Ontology
Answers the question: What SoftwareCode was used to generate the Model output?
Defined in: The LiPD Ontology
Answers the question: In which column of the csv file can the Variable be found?
Defined in: The LiPD Ontology
Answers the question: What is the digital object identifier associated with the resource?
Defined in: The LiPD Ontology
Answers the question: What is the command to run the script or the code?
Defined in: The LiPD Ontology
Answers the question: In which environment is the script meant to be run in?
Defined in: The LiPD Ontology
Answers the question: What is the name of the csv file in which the Variable values are stored?
Defined in: The LiPD Ontology
IGSN identifier associated to a physical sample
Defined in: The LiPD Ontology
Answers the question: What is the integration time needed for a ProxySensor to imprint environmental information on the ProxyArchive? Both are included as part of a ProxySystem
Defined in: The LiPD Ontology
Answers the question: What is the international book number of the Publication?
Defined in: The LiPD Ontology
Answers the question: What is the International Standard Serial Number of the Publication?
Defined in: The LiPD Ontology
Answers the question: What is the universal resource locator to a resource?
Defined in: The LiPD Ontology
Answers the question: What is the maximum value of the Variable?
Defined in: The LiPD Ontology
Answers the question: What is the mean value of the Variable?
Defined in: The LiPD Ontology
Answers the question: What is the median value of the Variable?
Defined in: The LiPD Ontology
Answers the question: What is the minimum value of the Variable?
Defined in: The LiPD Ontology
Answers the question: How are the missing values of the Variable identified in the DataTable?
Defined in: The LiPD Ontology
Answers the question: What is the ProxySystem associated with this MeasuredVariable?
Defined in: The LiPD Ontology
Answers the question: What is the importance of the Interpretation?
Defined in: The LiPD Ontology
Answers the question: What is the Resolution of the Variable?
Defined in: The LiPD Ontology
Answers the question: What is the Uncertainty associated with the Variable, Model, or Instrument?
Defined in: The LiPD Ontology
Answers the question: In what unit of measure is (are) the Variable(s) expressed?
Defined in: The LiPD Ontology
Answers the question: What are the numerical values of the Variable, Uncertainty, and Model outputs?
Defined in: The LiPD Ontology
Answers the question: What is the unique identifier for the Variable?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: In which laboratory/repository is the Instrument/PhysicalSample located?
Defined in: The LiPD Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Sensor Ontology
Inductively coupled plasma atomic emission spectroscopy (ICP-AES), also referred to as inductively coupled plasma optical emission spectrometry (ICP-OES), is an analytical technique used for the detection of trace metals.
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Answers the question: Which ChronData are included in the Dataset?
Defined in: The LiPD Ontology
Answers the question: Which Data are included in the Dataset?
Defined in: The LiPD Ontology
Answers the question: Which PaleoData are included in the Dataset?
Defined in: The LiPD Ontology
Answers the question: Which Variables are included in the DataTable?
Defined in: The LiPD Ontology
Answers the question: From which MeasuredVariable(s) is (are) the InferredVariable inferred from?
Defined in: The LiPD Ontology
A Variable that is inferred from one or more MeasuredVariable (s)
Defined in: The LiPD Ontology
Answers the question: What type of InferredVariable does the InferredVariable belongs to?
Defined in: The LiPD Ontology
An inorganic substrate sensing enviromental changes. Examples: karst, snow, watershed, ice sheet, rock, etc.
Defined in: The LiPD Ontology
A tool used to produce MeasuredVariables
Defined in: The LiPD Ontology
The time it takes for the ProxySensor to imprint environmental information on the ProxyArchive. It may be further qualified with time periods and units
Defined in: The LiPD Ontology
A suite of metadata that describes which phenomena drove variability in this Variable (e.g. environmental drivers).
Defined in: The LiPD Ontology
Answers the question: Is the InferredVariable value increasing or decreasing as the value of the MeasuredVariable is increasing?
Defined in: The LiPD Ontology
Answers the question: In which Publication(s) is the Interpretation substantiated?
Defined in: The LiPD Ontology
Answers the question: What is the Variable's Interpretation?
Defined in: The LiPD Ontology
An isotope-ration mass spectrometer measures the relative abundance of isotopes in a given sample.
Defined in: The Instrument Ontology
Answers the question: Does the Interpretation describe local variability, or far-field variability that may not reflect local conditions?
Defined in: The LiPD Ontology
Atoms can be simply described as consisting of protons, electrons, and neutrons. Isotopes of the same element differ by the number of neutrons in the nucleus, resulting in different mass.
Defined in: The Proxy Observation Type Ontology
Defined in: The Instrument Ontology
Defined in: The Inferred Variable Ontology
Answers the question: In what issue of the journal can the resource be found?
Defined in: The LiPD Ontology
Answers the question: What is the name of the journal in which the resource can be found?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
The geographic data and metadata for the dataset
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Marine sediments are a type of proxy archives that provide long, continuous records of past ocean variability. The timescales associated with this archive are usually in the order of several tens to millions of years. The resolution of the sedimentary archive varies from annual to multi-century. Paleoceanographic data are derived from many sensors found in deep-sea sediments including trace metal and isotopic composition of foraminifera, alkenones, and TEX86.
Defined in: The Proxy Archive Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Answers the question: Which Instrument was used to produce the MeasuredVariable?
Defined in: The LiPD Ontology
Answers the question: On which PhysicalSample was the MeasuredVariable measured?
Defined in: The LiPD Ontology
Variables that are measured by an Instrument. MeasuredVariables are ssn: Observations. They represent the values of a certain type of ProxyObservations
Defined in: The LiPD Ontology
DataTable that contains the Variables (both measured and inferred)
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Answers the question: How is the information obtained from the resource?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
A mathematical construct that is at least partially isomorphic to the target system, and is used to derive information about the structure and/or dynamics of the target system
Defined in: The LiPD Ontology
Answers the question: What is the Model for the Data, Compilation or ProxySystem under consideration?
Defined in: The LiPD Ontology
Answers the question: In which Publication is the model described/applied?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: How is the resource called?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
A publication that has not undergone a formal review process; for instance, a Dataset attached to a dissertation.
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Instrument Ontology
Answers the question: What additional information would you give about the Variable or DataTable ?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Answers the question: What is the persistent digital identifier of the Person?
Defined in: The LiPD Ontology
Paleoceanographers use the term biomarker to describe organic molecules found in marine sediments, initially produced by a variety of organisms either on land or in the marine environment [1]. A key characteristic of biomarkers is their ability to survive deposition in the archive in terms of their original structure and steroidal configuration (i.e., spatial distribution of the atoms) [1]. Their usefulness for paleoceanographic reconstructions largely depends on their degradation within the archive [1].
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Biologically-mediated ProxySensor. Examples include: foraminifera, trees, mollusks, polyps
Defined in: The LiPD Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: In what pages of the Publication can the reference to the resource be found?
Defined in: The LiPD Ontology
The Data pertaining to past environmental variability
Defined in: The LiPD Ontology
DataTable containing PaleoData Variables
Defined in: The LiPD Ontology
Model used to derive an environmental axis from the PaleoDataModel
Defined in: The LiPD Ontology
Answers the question: What is the PaleoModel for the PaleoData or ProxySytem under consideration?
Defined in: The LiPD Ontology
Climate observations prior to the instrumental era are necessarily indirect. These observations are made on climate proxies in various geological (e.g. lake or marine sediments, living or fossil coral reefs, cave deposits), glaciological (ice cores or snow pits) or biological (trees) archives. Many types of measurements can be made on each archives, each sensing a different aspect of the environment (sometimes, several aspects at once). A paleoclimate dataset is a set of observations made on an archive.
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Answer the question: Which compilation does a dataset belong to?
Defined in: The LiPD Ontology
Defined in: The Proxy Archive Ontology
A Publication that has undergone a formal peer-review process
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
An individual who has participated directly or indirectly in the authoring of any resources on the LinkedEarth wiki
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
The actual sample on which the measurements are made. For instance, the lake core analyzed in the lab is the physical sample.
Defined in: The LiPD Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Answers the question: Who was the lead on the source of Funding for the Dataset?
Defined in: The LiPD Ontology
Answers the question: In which language was the software code written in?
Defined in: The LiPD Ontology
According to the Evans et al. (2013), the medium in which the response of a ProxySensor to environmental forcing is recorded. Example of archives include: marine sediments, corals, wood, lake sediments, speleothems, glacier ice
Defined in: The LiPD Ontology
A Model of how the ProxySensor either creates or emplaces the signal into the ProxyArchive. Sensu Evans et al. (2013)
Defined in: The LiPD Ontology
Answers the question: Which ProxyArchive underlies this ProxySystem?
Defined in: The LiPD Ontology
The type of MeasuredVariables measured on the ProxyArchive, whether chemical (e.g. Mg/Ca, D18O, Sr/Ca), physical (e.g. density, layer thickness), or biological (e.g. Species abundance)
Defined in: The LiPD Ontology
The Model of how ProxyObservations are made on the archive. Sensu Evans et al. (2013)
Defined in: The LiPD Ontology
Answers the question: What type of ProxyObservation does the MeasuredVariable or Proxy System belong to? For example, the measured value of 5.63 mmol/mol is of type Mg/Ca, or the proxy observation of the current prpoxy system is Mg/Ca
Defined in: The LiPD Ontology
The sensor comprises physical, chemical, and/or biological components that react to environmental conditions. Sensors often respond to more than one environmental variable, and may have complex responses to the environment they sense, including thresholds (record only part of the range of environmental conditions), seasonal biases (record environmental conditions over a few months of the year), and/or nonlinear responses (Evans et al. (2013)). Signals recorded by the ProxySensor are imprinted onto the ProxyArchive.
Defined in: The LiPD Ontology
A Model of the ProxySensor. Sensu Evans et al. (2013)
Defined in: The LiPD Ontology
Answers the question: Which ProxySensor underlies this ProxySystem?
Defined in: The LiPD Ontology
Climate observations prior to the instrumental era are necessarily indirect. These observations are made on climate proxies in various geological (e.g. lake or marine sediments, living or fossil coral reefs, cave deposits), glaciological (ice cores or snow pits) or biological (trees) archives. Many types of data can often be collected from each archives, each sensing a different aspect of the environment (sometimes, several aspects at once). A paleoclimate dataset is almost always a time series of observations made on an archive.
Evans et al. (2013) [1] define a proxy system as comprised of three components (Fig 1).:
These three major components may be individually modeled, and linked together within a Proxy System Model [1] [7]. Some sensors are common to multiple archives (e.g. ?18O), and all archives support more than one possible sensor.
Defined in: The LiPD Ontology
In the Evans et al. (2013) framework, this is the combination of sensor, archive and observation models . "A generalized proxy system model encapuslates a simplified representation of prior physical, chemical, biological, and/or geological understanding of the ways in which environmental variation ultimately results in the observations used to retrieve paleoclimatic information."
Defined in: The LiPD Ontology
A document that serves as reference for a Dataset or its components
Defined in: The LiPD Ontology
Answers the question: What year was the Publication issued?
Defined in: The LiPD Ontology
Answers the question: In which Publication was the Dataset or Compilation issued?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: Which part of the publication describes the Calibration or Interpretation?
Defined in: The LiPD Ontology
Answers the question: In which EnsembleTable, DistributionTable, and/or SummaryTable is the Uncertainty reported?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Refers to the time difference between two adjacent values of a Variable.
Defined in: The LiPD Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Instrument Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Archive Ontology
Answers the question: how would you classify the Interpretation? Examples include Isotope, Climate…
Defined in: The LiPD Ontology
Answers the question: To which part of the year is the Interpretation or ProxySensor restricted to? Acceptable answers may be "MJJA", "growing season",or [5,6,7,8]
Defined in: The LiPD Ontology
The temperature close to the ocean's surface
Defined in: The Inferred Variable Ontology
Defined in: The Instrument Ontology
Answers the question: What is the Genus of the Organic ProxySensor?
Defined in: The LiPD Ontology
Answers the question: What is the species of the Organic ProxySensor?
Defined in: The LiPD Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Sensor Ontology
A script that describes the model, in any programming language (e.g., Excel, Matlab, Python, R)
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Instrument Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Archive Ontology
Defined in: The Proxy Observation Type Ontology
Carbon in nature exists in oxidized (i.e., CO2 and carbonates), elemental (i.e., graphite and diamond), and reduced (i.e., methane and organic matter]) forms. Carbon has two stable isotopes: the light isotope 12C (abundance: 98.9%, mass: 12.000000 amu) and the heavy isotope 13C (abundance: 1.1%, mass: 13.003355 amu). Since the mass of 13C is higher than the mass of 12C, the carbon isotopes are fractionated by chemical and biological processes. In general, 12C is strongly partitioned into organic matter (reduced form) while the heavy isotope is concentrated in the oxidized forms of carbon.
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Answers the question: Reference material against which the MeasuredVariable is reported?
Defined in: The LiPD Ontology
A DataTable that contains summary information for the Variable and is output from a Model.
Defined in: The LiPD Ontology
Answers the question: In which SummaryTable can the statistics on the Model Output be found?
Defined in: The LiPD Ontology
Defined in: The Inferred Variable Ontology
Answers the question: At which depth in the ProxyArchive is the Variable measured or inferred?
Defined in: The LiPD Ontology
Thermodynamic property allowing to quantitatively measure how warm or cold a material, fluid is.
Defined in: The Inferred Variable Ontology
The use of TEX86 (TetraEther indeX of 86 carbons) as a tool to reconstruct past sea surface temperature variability is based on the relative cyclization of isoprenoidal glycerol dialkyl glycerol tetra ethers (GDGTs) produced by marine archaea. TEX86 is defined as [1]: TEX_{86}=\frac{GDGT-2+GDGT-3+Cren'}{GDGT-1+GDGT-2+GDGT-3+Cren'} where GDGTs 1-3 indicate compounds containing 1-3 cyclopentyl moieties, respectively, and Cren' denotes the regioisomer of crenarchaeol, a diagnostic biomarker for the Thaumarchaeota, the primary producers of GDGTs in the marine realm. By definition, values of the TEX86 index are comprised between 0 and 1. Experimental evidence suggests that archaea produce GDGTs with more rings warmer waters, a response observed in cultures of hyperthermophile archaea [2] [3] and mesocosm experiments with natural seawater containing heterogenous archaeal population [4] [5]. References [1] Schouten, S., Hopmans, E. C., Schefuß, E., & Sinninghe Damsté, J. S. (2002). Distributional variations in marine crenarchaeotal membrane lipids: a new organic proxy for reconstructing ancient sea water temperatures? . Earth and Planetary Science Letters, 204, 265-274. [2] de Rosa, M., Esposito, E., Gambacorta, A., Nicolaus, B., & Bu'Lock, J. (1980). Effects of temperature on ether lipid composition of Caldariella acidophilia. Phytochemistry, 19, 827-831. [3] Uda, I., Sugai, A., Itoh, Y., & Itoh, T. (2001). Variation in molecular species of polar liipds from Thermoplasma acidophilum depends on growth temperature. Lipids, 36, 103-105. [4] Wuchter, C., Schouten, S., Coolen, M. J. L., & Sinninghe Damsté, J. S. (2004). Temperature-dependent variation in the distribution of tetraether membrane lipids of marine Crenarchaeota: implications for TEX86 paleothermometry. Paleoceanography, 19, PA4028. doi:10.1029/2004PA001041 [5]Schouten, S., Forster, A., Panato, E., & Sinninghe Damsté, J. S. (2007). Towards the calibration of the TEX86 paleothermometer on ancient greenhouse worlds. Organic Geochemistry. doi:10.1016/j.orggeochem.2007.05.014
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Answers the question: What is the title of the Publication?
Defined in: The LiPD Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Proxy Observation Type Ontology
The C37 alkenone unsaturation index ( U_{37}^{k'} ) is a firmly established tool for past sea surface temperatures reconstruction and is based on the relative abundance of di- (C37:2) and tri- (C37:3) unsaturated ketones with 37 carbon atoms. The index varies between 0 and 1, thus it may saturate in the temperature extremes as it becomes more challenging to determine since C37:3 and C37:2 alkenones approach their detection limits. Since alkenones come exclusively from a few species of haptophyte algae which require sunlight, alkenone thermometry offers the advantage of direct estimate of near-surface ocean temperatures. The ubiquitous presence of alkenone-synthesizing organisms (most commonly the coccolithophorids Emiliania huxleyi and Gephyrocapsa oceanic through the world's ocean and the rapidity and high-precision of the alkenone analyses had made U_{37}^{k'} a valuable proxy for paleoceanographic reconstructions. However, the U_{37}^{k'} proxy is subject to non-temperature effects, such as lateral transport through oceanic currents (Ohkouchi et al. (2002)) and preferential post-depositional oxidation of C37:3 compared to C37:2 [1] [2]. Furthermore, changes in the seasonality of the proxy (i.e., which part of the seasonal cycle the proxy is recording) may bias the inferred temperatures toward winter or summer conditions [3]. Finally in oceanic regions where the photic zone extends below the surface mixed layer, the sedimentary signal may not strictly represent sea surface temperatures but rather a composite temperature of the mixed layer and the thermocline [4][5]. References [1] Hoefs, M. J. L., Versteegh, G. J. M., Rijpstra, W. I. C., de Leeuw, J. W., & Damsté, J. S. S. (1998). Postdepositional oxic degradation of alkenones: Implications for the measurement of palaeo sea surface temperatures. Paleoceanography, 13(1), 42-49. doi:10.1029/97pa02893 [2] Ohkouchi, N., Eglinton, T. I., Keigwin, L. D., & Hayes, J. M. (2002). Spatial and temporal offsets between proxy records in a sediment drift. Science, 298(5596), 1224-1227. doi:10.1126/science.1075287 [3] Herfort, L., Schouten, S., Boon, J. P., & Sinninghe Damsté, J. S. (2006). Application of the TEX86 temperature proxy in the southern North Sea. Organic Geochemistry, 37, 1715-1726. [4] Müller, P. J., Kirst, G., Ruhland, G., von Storch, I., & Rosell-Melé, A. (1998). Calibration of the alkenone paleotemperature index U_{37}^{k'} based on core-tops from the eastern South Atlantic and the global ocean (60°N-60°S). Geochimica et cosmochimica acta, 62, 1757-1772. [5] Prahl, F. G., Mix, A. C., & Sparrow, M. A. (2006). Alkenone paleothermometry: biological lessons from amrine sediment records off Western South America. Geochimica and Cosmochimica Acta, 70, 101-117.
Defined in: The Proxy Observation Type Ontology
The currently accepted U37kprime (Prahl and Wakeman, 1987) varies positively with temperature, and is defines as C(37:2)/(C(37:2)+C(37:3), where C(37:2) represents the quantity of the di-unsaturated ketone and C(37:3) the quantity of the tri-unsaturated form. Herbet, T.D., 2003, Alkenone paleotemperature determinations in Treatise on Geochemistry, Volume 6, pp 391-432
Defined in: The Proxy Observation Type Ontology
A state of incomplete knowledge that results from a lack of information or from different modeling choices. Uncertainty may come from many sources, from imprecision in the data to ambigously defined concepts or terminology. Uncertainty can be represented by quantitative measures (e.g., probability density function) or by qualitative statements (e.g., reflecting the judgement of a team of experts). Sensu IPCC AR5
Defined in: The LiPD Ontology
Answers the question: What parameter of the error distribution is the Uncertainty value referring to? Examples include 1-sigma, 2-sigma, 95% confidence bounds
Defined in: The LiPD Ontology
A Model quantifiying the Uncertainty
Defined in: The LiPD Ontology
Quantities that may change from value to value. They are usually represented as column of values in a data table
Defined in: The LiPD Ontology
Defined in: The Proxy Sensor Ontology
Answers the question: In which volume of the Publication does the reference to the Datatset appear?
Defined in: The LiPD Ontology
Defined in: The Proxy Sensor Ontology
Defined in: The Instrument Ontology
The field of dendroclimatology and, to some extent, the field of dendrochronology have played an important role in generating climate reconstructions of the past millennium [1] [2] [3] [4]. In regions with large seasonal variations, trees produce rings of varying color depending on the species. In most cases, the rings shift from a lighter, low density early wood of spring and early summer to a darker, denser band of late wood at the end of the growing season. The growing season generally occurs during the summer month and its length depends on the species, latitude, and altitude. Therefore, trees hold perhaps the greatest potential for reconstructing past terrestrial climates at annual or even sub-annual resolution.
The following observations can be made on the wood archive:
Defined in: The Proxy Archive Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Proxy Observation Type Ontology
Defined in: The Inferred Variable Ontology
Defined in: The Instrument Ontology
Defined in: The Proxy Observation Type Ontology