Beyond Retention Periods: Appraising Climate Data Across Complementary Archives

Efficient long-term data archiving is essential for advancing climate research, where increasingly complex simulations generate vast and heterogeneous datasets that must remain accessible, traceable, and reusable across disciplines and timescales. To meet the diverse, user-specific needs of Earth System Sciences (ESS) researchers, the German Climate Computing Center (DKRZ) provides two complementary archival systems: WDCC and DOKU. 

The World Data Center for Climate (WDCC) serves as a formal, FAIR-aligned repository for climate model outputs and related datasets. It assigns persistent identifiers via DataCite DOIs, preserves rich and standardized metadata, and ensures interoperability, thereby promoting data sharing and supporting long-term scientific reuse. Mature datasets intended for public dissemination and sustained reuse therefore fall in the scope of WDCC. DOKU, by contrast, is a lightweight, flexible solution tailored to project- and user-specific requirements within DKRZ. It offers structured long-term storage - typically guaranteed for ten years - for data that are not (yet) ready for formal publication but remain important for internal reference, validation, or project continuity.

A central question for researchers is however not only where but also which data should be kept, and for how long. While DOKU and WDCC each provide a baseline retention period of ten years, it is worth considering whether time alone is really the decisive criterion for preservation. Instead appraisal could consider scientific value, future potential for reuse, the cost of regeneration, and broader considerations of good scientific practice. 

Starting with DOKU, appraisal criteria and workflows are currently being developed to determine the fate of archived data once the guaranteed retention period has expired. Data that continue to play a significant role within their project or show clear potential for reuse might stay longer in DOKU while others might need to go. Once this workflow has been established and tested it could also serve as a blueprint for WDCC. 

Together, WDCC and DOKU form a coherent strategy for sustainable data management, providing scalable infrastructure, FAIR principles, and software solutions that meet specific user needs while supporting responsible, long-term stewardship of climate data across the ESS community.