Proposals should address the following:

• Assessment of current in-situ observing capabilities and protocols of the terrestrial and marine domains, including hydrology, with emphasis on the coastal zones and focus on terrestrial/hydrological input to the sea (delta’s, river input, agricultural and other run-off, etc.), including issues of spatial and temporal resolution, identification of important gaps and proposals for viable, long-term approaches to address them;
• Development of methods, tools, technologies and processes to fill the identified gaps following the assessment and to increase integrated observing capacity in the coastal zones and in the land-sea interface (including hydrological inputs). These developments should also contribute to upgrading, enhancing and interconnecting the existing observing networks, developing new capacity when necessary;
• Development of interoperability standards between terrestrial and marine data and coordination of existing observation services and networks (EMODnet, Copernicus, GEOSS, WISE, LUCAS, INSPIRE etc.) to promote freely available and uninhibited flows of FAIR data and to support the creation of data products in the land-sea interface; combination of in-situ observation from land and sea with satellite observation to fill otherwise unaddressed gaps;
• Advance forecasting and modelling capacity in the coastal zones, including for predicting hazardous events, addressing habitat and biodiversity loss, assessing lateral carbon fluxes across the land ocean continuum, addressing shoreline issues such as erosion, detecting/quantifying/managing the impacts of human activity and extreme events due to climate change, and the better integration of river runoffs into marine-related predictions (including the inflow of plastic and nutrient loads through rivers and estuaries);
• Developing close coordination and collaboration across scientific communities (e.g., in-situ data, satellite base observations) ensuring data consistency, cross-fertilisation and enhanced data integration.

In the framework of the Digital Twin Ocean (DTO) and Destination Earth (Destin): the development of integrated observation capacities between land and sea, in the coastal zones and beyond, is necessary to address priorities. These can include the decrease of pollution, protection and conservation of biodiversity and prediction/adaptation to climate change effects related to e.g., erosion, to the loss of land and ecosystems, land and coastal marine heatwaves, acidification, storm surges, floods and salinization.