Implementing FAIR principles for Theia/OZCAR in situ data information system – FairTOIS

The Theia/OZCAR SI is developed based on international data exchange standards (INSPIRE, OGC) and is committed to implementing the FAIR principles, iespecially to prepare the French community for the integration of European projects.

All these developments are carried out in collaboration with IR Data Terra, and the data poles of the other major compartments of the earth system (ocean, atmosphere, internal earth), to guarantee the interoperability of systems and data. Developments are also regularly presented and coordinated with the European eLTER team.

The FairTOIS project has consolidated and enriched the implementation of the FAIR principles in 3 aspects: (1) data discovery via standardized names of variables and objects of interest, using the i-Adopt framework; (2) metadata interoperability, by implementing a standardized web service; and (3) dissemination and training of FAIR data principles in the Continental Surfaces and Critical Zone community via the OZCAR RI meetings and the contributions to several thematic schools.
The project has thus made it possible to improve the visibility of the observatories: at the start of the project, 7 out of 22 observatories were visible on the Theia/OZCAR portal. This figure rose to 16/22 at the end of the FairTOIS project, which is a clear improvement, but still remains unsatisfactory.

In coordination with the European team, a workflow using interoperability services was set up in 2021. It automatically feeds the new European eLTER portal with all the datasets present in OZCAR/Theia IS.

The Theia/OZCAR national inter-agency project does not stop with the end of the FairTOIS project. The next steps identified are both to continue the development of the portal and to increase the number of visible observatories, always in consultation with our national and international partners.

The web portal offer will evolve to offer in particular the visualisation and downloading of data. Theia/OZCZAR will thus make it possible to have an identical output format for the variables chosen, regardless of the origin of the data. This point was identified as time-consuming and even blocking by data users during consultation meetings.

The second objective is to mobilize and help the scientists of the observatories to make their data available. We are therefore going to set up an API using the interoperability services (CSW, SensorThings) for the observatories that have requested it. We have also identified the need and drafted the profile of a «data curator«, in order to support scientists in the description of their data.

Journal articles:
• Braud I., V. Chaffard, C. Coussot, S. Galle, P. Juen, and the Theia/OZCAR team (25 co-authors), 2020. « Building the Information System of the French Critical Zone Observatories Network: Theia/OZCAR-IS ». Hydrological Sciences Journal Special Issue: Hydrological data: opportunities and barriers. 02626667.2020.1764568 ; doi.org/10.1080/02626667.2020.1764568 ?hal-insu-02917629?
• Beretta, V., Desconnets, J.-C., Mougenot, I., Arslan, M., Barde, J., and Chaffard, V.: A user-centric metadata model to foster sharing and reuse of multidisciplinary datasets in environmental and life sciences, Computers & Geosciences, 154, 104807, doi.org/10.1016/j.cageo.2021.104807, 2021.

Miscellaneous:
• website Theia/OZCAR : www.theia-land.fr/product/donnees-in-situ/
• Digital Management Plan (DMP) of the Theia/OZCAR Information System. Accessible on line via OPIDOR : dmp.opidor.fr/public_plans , 20 p.
• Data portal Theia/OZCAR : in-situ.theia-land.fr
• Thesaurus Theia/OZCAR : w3id.org/ozcar-theia ; DOI 10.17178/67b5a1d5-8c8c-4a94-a646-1cca1d0adf79
• GitHub Theia/OZCAR : github.com/theia-ozcar-is/
• User guide for data producers (thesaurus, Theia/OZCAR pivot data model, data deposit procedure): theia-ozcar.gricad-pages.univ-grenoble-alpes.fr/doc-producer/producer-documentation.html
• User guide to create a dataset from BDOH Chronicles and upload it to Theia/OZCAR IS: nextcloud.inrae.fr/s/pSTgPPERoPBAKwH

The aim of the Theia/OZCAR Information System (IS) is to make all the continental surfaces in-situ data visible and easy to access and to facilitate their discovery on a single portal managed by the French data pole “Theia”. The project will start with the OZCAR (French network of Critical Zone observatories) Research Infrastructure (RI), before extending to data from other sources (research programs, non-labeled observatories). The IS is currently developed, based on data exchange standards (INSPIRE, OGC) and is committed to implementing the FAIR principles, especially to prepare the French community to integrate European RI such as eLTER-RI (European Long Term Ecological Research), recently accepted on the European roadmap and whose French mirror eLTER-France includes the OZCAR RI. The IS will also allow data DOI assignment with rich metadata.

The OZCAR RI coordinates 21 labeled observatories which manage some sixty sites in France and abroad (North and West Africa, Asia, South America, Arctic) ranging from a few hectares to several hundred km². These observatories collect in situ long-term data from continental areas, some of which start as early as 1960. The initial practices and objectives of the observatories are different, which has led to the choice of different sampling protocols and measuring sensors. In the current census there are more than 300 variables measured by OZCAR observatories (including both physical variables and chemical species). In situ data are mainly point time series, but also gridded data, vector data, or 2D profiles.

The complexity of Theia/OZCAR IS does not lie in the total amount of data stored (around 10 TB), but in the variety of data and metadata needed to contextualize them (variables, objects of interest, acquisition methods); and the heterogeneity of existing distributed information systems to describe and disseminate data from each observatory.

To develop the Theia/OZCAR IS it was chosen, in agreement with the experience of the Earth System RI, to leave the data close to the producers, to ensure their quality. The observatories will continue to distribute their data in the IS they have developed, while a pivot model with rich metadata based on standards, has been defined to ensure the flow of information between the observatories and the Theia/OZCAR IS, which implements the FAIR principles. This iterative approach creates a network and allows to rely on the complementary skills of the observatories IT Teams in term of data management. A data portal prototype, focused on point time series, is available and a third of the observatories have already implemented information flows with the Theia/OZCAR IS. The FairTOIS project aims to consolidate and enrich the implementation work of the FAIR principles started two years ago on 3 aspects: (1) data discovery through standardized variable names and object of interest, as well as access to data; (2) development of data interoperability; and (3) dissemination of FAIR data principles in the Continental Surfaces community via the OZCAR RI. All of these developments will be carried out, as for current developments, in connection with the Earth System RI and data poles of other disciplines, to ensure the interoperability of systems and data. The work done will also allow the French community to be a source of proposals for the construction of the eLTER IS, having already a shared vision of the management of a much wider data panel than the one currently treated in eLTER.