SIOS Core Data

Submitted on 2020-04-17; Updated on 2026-01-15

SIOS Core Data

SIOS Core Data consist of a list of essential Earth System Science (ESS) variables relevant to determine environmental change in the Arctic. SIOS Core Data are developed to improve the relevance and availability of scientific information addressing ESS topics for decision-making. SIOS Core Data providers have committed to maintain the observations for at least five years, to make the data publicly available, and to follow advanced principles of scientific data management and stewardship.

SIOS Core Data Schematic
What are SIOS Core Data?

SIOS Core Data comprise the critical data needed to scientifically assess the state of the environment in Svalbard.

The first set of SIOS Core Data variables was partly derived from the list of Essential Climate Variables (ECVs) defined by the Global Climate Observing System (GCOS). The most relevant variables for Svalbard were identified by the SIOS’ Scientific Optimisation Advisory Group (SOAG) in cooperation with the Research Infrastructure Coordination Committee (RICC) and scientific experts.

To qualify as SIOS Core Data, the data must meet the three criteria described below: 

  1. Scientific requirements

    The variable must be critical in answering the key ESS research questions as defined in the SIOS infrastructure optimisation report, and further updates in SESS reports.

    The requirement for temporal and spatial coverage varies between variables and potentially depending on the scientific question. This should be considered in the scientific requirement (optimisation). Connection with GCOS ECVs and other Essential variable schemes, as for example Essential Ocean Variables, and marine Essential Biodiversity Variables, can provide guidelines and criteria for selection and prioritisation.

  2. Data availability

    The data must be available through the SIOS Data Management System (SDMS) and accessible in the SIOS Data Access Portal. 

    Data must be described with rich discovery and use metadata. Where possible, existing measurement and calibration protocols (e.g. WMO, GAW, BSRN11, ACTRIS and ICOS12) should be used to collect SIOS Core Data to secure comparability.

  3. Collecting commitment

    There must be a commitment from the data-providing institute to maintain the measurement infrastructure setup and data production for at least 5 years, as well as making the data available through SDMS.

SIOS Core Data Candidates

SIOS Core Data Candidates are data that fulfil the criteria outlined above but are not yet available online. SIOS provides support for its member institutions in transforming SIOS Core Data Candidates into SIOS Core Data.

SIOS Core Data Categories

SIOS Core Data are divided into 4 categories:

Access to the SIOS Core Data datasets in the SIOS Data Access Portal:

SIOSCD collection in the Data Access Portal 

Why do we need SIOS Core Data?

  • SIOS Core Data variables are critical for characterising the climate system and its changes in the Arctic, and answering key Earth System Science research questions prioritised by the SIOS community.

  • SIOS Core Data are useful to ensure a consistent, harmonized baseline of essential environmental variables that the research community can use to monitor long-term changes in the Arctic system.

  • The SIOS Core Data definition process promotes compliance with FAIR guiding principles for scientific data management and stewardship for key datasets.

  • The commitment to long-term data collection and open access supports reliable, reproducible research, enabling both modelling efforts and decision-making for environmental policy and climate resilience.

  • SIOS Core Data support the optimization of SIOS’s observing system: by defining and maintaining core variables, SIOS and the research community can better prioritize resources, standardize protocols, and identify observational gaps.

Proposing new inclusions to the SIOS Core Data variables set

SIOS Core Data are a dynamic set of key variables and it is possible for institutions or individuals to propose new inclusions to the SIOS Core Data variables set. The instructions for the process can be found here. The Science Optimisation Advisory Group will review the proposals in their regular meetings.