Ocean observing is executed and financed by nations according to their national interest and needs, but aligned with European and international agreements and directives. ObsSea4Clim brings together key European and international actors within ocean observing science, climate assessment, Earth System modelling, data sharing and standards, with users of oceanographic products and services with the goals of: - improving sustained and multipurpose observations vital to European and global climate requirements, and - delivering an improved observation framework based on EOV/ECVs and embedded in a Rolling Review of Requirements approach. ObsSea4Clim will: - improve regional and global climate assessments and - provide projections and actionable indicators for sustainable development provided. The work program is organized around four building blocks (TRL7-8): 1- the EOV/ECV concept, 2- the regional ocean indicator concepts, 3- the nations’ multi-purpose (climate, services, ocean health) ocean observing, 4- the integration with European and global initiatives. ObsSea4Clim will make use of ocean climate application areas such as: sea ice loss, ocean transports, stratification, sea level, ocean warming and marine heat waves and ocean mesoscale. Regional observing will be transformed into an EOV/ECVs framework suitable for regional and global climate products, ESM development (CMIP7) and indicators. ObsSea4Clim will also link to the Mission Restore our Ocean 2030 lighthouse basins. AI methods will control data quality and unlock EOV/ECVs from existing data repositories. ObsSea4Clim will promote the implementation of FAIR/CARE data, enabling and advocating their use for versatile applications and referenced to an EOV/ECV framework. ObsSea4Clim will actively lead the dialogue with European and international climate and data initiatives to ensure the necessary exchanges for implementing the ObsSea4Clim results into the international system. In this way, ObsSea4Clim will ensure sustained EU leadership in the ocean–climate–biodiversity science nexus at a global level.

Although the Ocean is a fundamental part of the global system providing a wealth of resources, there are fundamental gaps in ocean observing and forecasting systems, limiting our capacity in Europe to sustainably manage the ocean and its resources. Ocean observing is “big science” and cannot be solved by individual nations; it is necessary to ensure high-level integration for coordinated observations of the ocean that can be sustained in the long term. EuroSea brings together key European actors of ocean observation and forecasting with key end users of ocean observations, responding to the Future of the Seas and Oceans Flagship Initiative. Our vision is a truly interdisciplinary ocean observing system that delivers the essential ocean information needed for the wellbeing, blue growth and sustainable management of the ocean. EuroSea will strengthen the European and Global Ocean Observing System (EOOS and GOOS) and support its partners. EuroSea will increase the technology readiness levels (TRL) of critical components of ocean observations systems and tools, and in particular the TRL of the integrated ocean observing system. EuroSea will improve: European and international coordination; design of the observing system adapted to European needs; in situ observing networks; data delivery; integration of remote and in-situ data; and forecasting capability. EuroSea will work towards integrating individual observing elements to an integrated observing system, and will connect end-users with the operators of the observing system and information providers. EuroSea will demonstrate the utility of the European Ocean Observing System through three demonstration activities focused on operational services, ocean health and climate, where a dialogue between actors in the ocean observing system will guide the development of the services, including market replication and innovation supporting the development of the blue economy.