This deliverable examines good practices for provenance and traceability in climate services, with particular attention to how data origins, processing methodologies, assumptions, limitations, and methodological choices can be documented and communicated in a user-friendly manner. Building on previous Climateurope2 work (D2.2), the report combines insights from interviews with institutional actors, national climate services, research infrastructures, operational data providers, and private-sector organisations, complemented by recent literature and technical developments. The analysis shows that provenance is increasingly recognised as essential for transparent, reproducible, and trustworthy climate services. However, the main challenges do not primarily concern the absence of technical standards, but their practical interpretation, governance, implementation effort, level of detail, and usability across different user groups. Climate service providers therefore need to balance technical reproducibility for expert users with clearer explanations that help downstream users understand the relevance, quality, uncertainty, and limitations of climate information. The report formulates fourteen recommendations that can be adopted progressively depending on organisational maturity, operational needs, and user priorities. Beyond presenting these recommendations, it offers a conceptual framework to help climate services prioritise provenance elements according to their relevance for different actors across the value chain, distinguishing between upstream technical reproducibility and auditability, and downstream interpretation, communication, and guidance. Overall, the deliverable provides a structured basis for future standardisation pathways and community coordination. It highlights that effective provenance should not be treated only as a technical backend requirement, but as a core component of quality management, transparency, user trust, and responsible climate-service provision.
Spinuso et al. (Tue,) studied this question.