TerraDT Workshop Report | Digital Twin Solutions for Sea Ice

1 1. Overview The Digital Twin Solutions for Sea Ice workshop brought together the EU-funded Nordic Cryosphere Digital Twin (NOCOS DT) and the TerraDT projects for two days of exchanges hosted by Tallinn University of Technology (TalTech) and online. The event combined the final conference of NOCOS DT, showcasing its six sea-ice research solutions, with TerraDT’s first sea-ice impact sector workshop, focused on user needs and future applications. A total of 67 participants attended the event in person or online, including national meteorological and environmental services, universities and research centres, infrastructure operators, maritime and shipping actors, other EU-funded initiatives, digital twin developers and private-sector stakeholders. Discussions covered applications from regional Baltic and Arctic use cases to the global Destination Earth (DestinE) ecosystem, highlighting how digital twins can improve understanding of sea-ice dynamics and support operational and policy decisions. Across the two days, several themes emerged. Sea-ice conditions in the Baltic and Arctic are changing rapidly, with direct implications for navigation, offshore energy, marine ecosystems and coastal planning. Digital twins are expected not only to provide more detailed data, but to deliver indicators to support decisions and what-if analyses. Integration with DestinE is essential for scalability and long-term operationalisation, while user-centred design remains critical to ensure that digital twins are accessible, trusted and useful in real-world contexts. 2 2. Objectives The overall event was designed to: 🌍Provide a comprehensive overview of the current state of the art and future potential of Earth System Digital Twins for sea-ice research and applications. 🌍Showcase the six sea-ice solutions developed within NOCOS DT and how they make use of advanced climate simulations. 🌍Introduce TerraDT’s sea-ice impact sector activities and explain how new digital twin components and impact models connect to DestinE. 🌍Facilitate dialogue between regional Nordic and Baltic case studies and global digital twin developments. 🌍Engage users and stakeholders in discussing future needs, technical requirements and collaboration opportunities across the digital twin ecosystem. 3 3. Day 1 Regional focus: Nordic and Baltic seaice applications 3.1 Setting the stage Day 1 opened with welcomes from partners involved in both projects, namely Tero Aalto, moderator of the event (CSC – IT Center for Science) and Rivo Uiboupin (TalTech), followed by a keynote from Ingrid Aukrust Rones (Nordic Council of Ministers) on the strategic importance of cryosphere-related technology for the region. The opening remarks underlined that the Nordic and Baltic countries combine long-standing operational experience in ice services with strong scientific and technological capacity, offering fertile ground for digital twin innovation. A presentation from Tarmo Sulg (Estonian Environment Agency) then showed how sea-ice information is already used operationally in Estonia, including public ice-chart services and ongoing work on a national Climate Atlas that will provide dynamically downscaled marine climate scenarios. Projections suggest notable reductions in winter sea-ice thickness and duration along the Estonian coast, making impact models increasingly important for ports, coastal infrastructure and safety. A final keynote by Nikolay Koldunov, (Alfred Wegener Institute) on cryosphere digital twin solutions placed this work in the wider Destination Earth (DestinE) context. He outlined how new digital twin components for land ice, sea ice, land surface processes and aerosols, together with dedicated impact models and supporting software infrastructure, are being developed to enhance the Climate Digital Twin and improve climate projections for decision-making. This framing emphasised the link between regional experimentation and global-scale climate services. 4 3.2 Sea-ice applications from NOCOS DT and TerraDT The following session presented sea-ice applications from both projects, illustrating the breadth of use cases and the variety of data, models and methods involved: 🌍Sea-ice impact modelling and ridged ice, presented by Ilja Maljutenko (TalTech): regional model configurations and particle-based approaches to trace deformed sea ice and assess its impact on offshore wind farms and shipping routes. 🌍Ship navigation risk indicators, presented by Xinfang Zhang (Finnish Meteorological Institute): metrics combining sea-ice, ice-ridge and environmental information to support winter navigation and optimise the use of icebreaking services. 🌍Landfast ice derivation, presented by Andrea Gierisch (Danish Meteorological Institute): tools for deriving landfast ice from climate simulations, enabling assessments of local ice conditions in fjords and coastal areas that are critical for communities and infrastructure. 🌍Marginal ice zone characterization, presented by Keguang Wang (Norwegian Meteorological Institute): methods to define and analyse the marginal ice zone, derive climatologies and support services based on improved Arctic sea-ice predictions. 🌍Sea-ice information for marine spatial planning, presented by Lars Arneborg (Swedish Meteorological and Hydrological Institute): workflows to translate sea-ice and climate projections into layers usable in marine spatial planning tools, including bias adjustment and efficient data processing pipelines. 🌍Discrete element modelling of sea ice, presented by Jan Åström (CSC): digital models of level ice interacting with offshore structures, demonstrating how wind-farm layouts influence ice loads and deformed-ice tracks. Taken together, these applications showed how high-resolution climate and sea-ice simulations can be transformed into sector-specific indicators for energy, navigation and long-term planning. 5 3.3 Panel discussions: infrastructure and life in the cryosphere The first panel on “Infrastructure in the cryosphere” explored the consequences of changing seaice conditions for marine spatial planning, offshore construction and naval architecture. Panellists underlined that sea ice and climate change are still insufficiently represented in spatial plans, even though future changes in ice regimes may significantly affect ecosystems and human uses. Digital twins can help quantify extreme conditions, stressors and risk pathways for infrastructure in ice-covered waters, and support more resilient design and operation. 6 The subsequent panel on “Life in the cryosphere” focused on navigation and winter transport. Experts from meteorological and ice services discussed operational requirements for reliable forecasts of ice drift, thickness and ridging at time scales relevant for shipping. They pointed to an opportunity for digital twins to enhance consistency across national services, improve communication of uncertainty and provide more user-friendly visualisations and indicators for ship operators and authorities. 3.4 Interactive session on user needs Day 1 concluded with an interactive session moderated by Diana Urquiza, (Barcelona Supercomputing Centre) on user needs and requirements for sea-ice impact models within digital twins. Participants, both on site and online, worked in small groups to map user profiles, describe real decision contexts and identify features that would make digital twins more useful in their work. Several recurring needs were identified: intuitive user interfaces and visualisations, stable and well-documented APIs for integration into existing workflows, clearer communication of uncertainty, and the provision of sector-specific indicators rather than raw model variables. The session reinforced the message that digital twin developments should start from user stories and co-design, rather than from technology alone. A poster session and networking cocktails provided additional space to explore the six NOCOS DT solutions and related activities, as well as preliminary TerraDT results in more detail. 7 4. Day 2 Global outlook: DestinE, integration and the wider EU digital twin ecosystem 4.1 Destination Earth and the cryosphere Day 2 shifted focus from regional applications to a global outlook. A keynote by Sebastian Milinski (ECMWF) on Destination Earth described the Climate Digital Twin, its use of kilometre-scale multi-decadal simulations on EuroHPC infrastructure, and recent progress in representing sea ice through refined ocean physics and improved atmosphere - sea-ice coupling. Embedding applications directly into the Climate Digital Twin workflow was highlighted as a key step towards enabling impact models and services to use climate simulations more directly and efficiently. The keynote also emphasised the significance of the European effort bringing leading climate-modelling institutes into a single integrated system, and the opportunity this creates for downstream initiatives such as TerraDT and NOCOS DT. 4.2 TerraDT integration with DestinE Devaraju Narayanappa (CSC)TerraDT and Ilja Maljutenko (TalTech) from NOCOS DT then presented how their architectures and components connect to DestinE. TerraDT adopts a modular, “plug-and-play” approach to digital twin components for land and sea ice, coupled to core models within DestinE. It also deploys impact models and interactive user interfaces on the DestinE platform, ensuring that cryosphere-focused services are aligned with the broader technical and governance framework. The session also addressed technical challenges, including data formats, compliance with a common data portfolio, and synchronising development timelines with operational production in the Climate Digital Twin. These issues are central to ensuring that innovations developed in projects can be sustained and scaled within an operational context. 8 4.3 The future of cryosphere-related data and services A panel on the future of cryosphere-related data and services brought together experts from TalTech, AWI and FMI to reflect on lessons from NOCOS DT and the goals of TerraDT. Panellists discussed the trend towards higher spatial and temporal resolution, the potential of artificial intelligence and machine learning to improve efficiency, and the need for interoperable, standardised data flows between climate simulations, digital twin components and downstream services. The discussion highlighted that, as data volumes grow, the key bottlenecks increasingly lie in usability, trust and institutional capacity to make use of advanced tools. Communicating uncertainty and limitations was seen as particularly important for high-impact decisions in navigation, infrastructure planning and adaptation strategies.