Successful proposals will contribute to the European Green Deal, addressing resilience to climate change (mitigation and adaptation) in coastal areas. Improved ocean models for 21^st century climate projections, from regional to coastal scales, and from seasonal to decadal timeframes, will support the sustainability of the blue economy and the protection of ocean health and coastal landscapes.

The proposals will support the Digital and Green Transitions and will directly support Destination Earth^[1] and the development of the Digital Twins, and the Digital Twin Ocean^[2] in particular. They should contribute to the improvement of marine information services provided by European programmes like Copernicus, and their uptake at local, coastal and EU regional levels.

Project results are expected to contribute to all the following expected outcomes:

• Demonstration of the fit for purpose and configuration of ocean models, for climate change impact assessment in European sea basins and coastal areas, in particular on marine ecosystems;
• Demonstration of EU basin scale to coastal ocean climate services that support policy implementation and the development of climate adaptation strategies and of a carbon-neutral blue economy (e.g., ocean climate risk services);
• Development and publication of indicators on ocean status and health, targeted towards territorial decision-makers, complementary to current Global Climate Observing System (GCOS) Essential Climate Variables^[3] or Copernicus Ocean State Reports^[4];
• Integration of the developments in the digital perspective, interoperable and/or integrable with Destination Earth and the Digital Twin Ocean;
• Fostered collaboration between the climate science community and operational oceanography communities (operating ocean services on a sustained way).

A current limitation to climate change projections for EU-basin scale to coastal use comes from an insufficient representation and resolution of basin and coastal ocean dynamics and from an unsatisfactory understanding of the oceanic biogeochemical cycle. Most climate models include the ocean dimension that stops at the regional scale as defined by meteorology and climatology like in CORDEX In parallel, operational oceanography centres develop and operate ocean models (physics, biogeochemistry, sea-ice) for daily ocean forecasting and reanalysis that represent more exhaustively the full ocean dynamics. Methods should help close the gap between current climate projections (global, centennial) on the one hand and existing Copernicus Marine physics and biogeochemical models used for daily ocean forecasting.

Proposals are expected to focus on:

• Developing capabilities for producing decadal to long-term (multi-decadal to centennial) refined predictions of the ocean state, at the scale of European regional seas including the coastal zones, where climate change risk is considered to be particularly high;
• Improving the representation of ocean processes (and dynamics, especially at regional to coastal scale) that can be integrated in in climate models;
• Developing capabilities for producing decadal to long-term EU basin scale predictions of biogeochemistry models to support feedback into global/regional marine ecosystem models and climate models;
• Validating the approach by performing historical runs and comparing corresponding model results to observations, proxy information, and / or reanalyses over an instrumental multi-decadal period, up to centennial scales, with characterized uncertainties;
• Investigating and assessing the quality of coastal models or ecosystem models of the low to mid trophic food web levels, over European seas and their coastal zones, with characterized uncertainties.

Methodology and developments should be benchmarked with two relevant use cases, to be showcased in three different European regional seas and coastal areas involving both scientists and end users:

• Development and demonstration of regional ocean climate risk services in coastal areas, due to sea level rise, waves, surges, or any other extreme event;
• Development and demonstration of regional ocean climate services in coastal areas supporting the blue economy (e.g. aquaculture, marine renewal energies, tourism).

Proposals shall demonstrate that the targeted scientific framework, ocean models integrated into EU basin scale climate models and resulting in basin scale ocean services for the marine and maritime sectors can be replicable to all EU regional seas. Proposals should plan resources for coordination and networking activities with related projects, in particular those funded under the Missions “Restore our Ocean and waters by 2030” and “Adaptation to Climate Change”, as well as with relevant projects funded under Cluster 4 – Space addressing Copernicus services (marine, land, emergency, climate), Cluster 5 Destination “Climate sciences and responses for the transformation towards climate neutrality”, and Cluster 6, as appropriate. These networking and joint activities could, for example, involve the participation in joint workshops, the exchange of knowledge, the development and adoption of best practices, or joint communication activities to break the silos between science communities.

The proposal should favour open data, open source, and public-use models and algorithms with open source licensing and integrable in the Digital Twin of the Ocean. Proposals should leverage the data and services available through European Research Infrastructures federated under the European Open Science Cloud, as well as data from relevant Data Spaces in the data-driven analyses. Projects could additionally benefit from access to infrastructure and relevant FAIR data by collaborating with projects funded under the topics HORIZON-INFRA-2022-EOSC-01-03: FAIR and open data sharing in support of healthy oceans, seas, coastal and inland waters and HORIZON-INFRA-2024-EOSC-01-01: FAIR and open data sharing in support of the mission adaptation to climate change.

Synergies and complementarities: HORIZON-CL6-2023-CLIMATE-01-08: Closing the research gaps on ocean Essential Climate Variables (ECVs) in support of global assessments, relevant EU Research Infrastructures.

In this topic the integration of the gender dimension (sex and gender analysis) in research and innovation content is not a mandatory requirement.

Activities are expected to achieve TRL 3-5 by the end of the project – see General Annex B.

[1] Destination Earth | Shaping Europe’s digital future (europa.eu)

[2] European Digital Twin of the Ocean (European DTO) | European Commission (europa.eu)

[3] GCOS | WMO

[4] Ocean State Reports | CMEMS (copernicus.eu)