
EDITO-Model Lab´s Coastal Hazards What-if Scenarios for the North Sea and Baltic Sea
Semi-enclosed Seas, Big Problems
Climate change continues to reshape the coastal landscapes of the North Sea and Baltic Sea, bringing rising sea levels, intensified storm surges, and coastal erosion. These challenges demand urgent action to safeguard communities, infrastructure, and ecosystems.
Municipalities, national agencies, and insurance companies are at the forefront, responding to storm events, mitigating risks, and planning long-term defences, like seawalls and sand nourishment. Yet, accessing the high-resolution data needed for precise decision-making has still been difficult, often requiring costly, time-consuming custom numerical modelling services.
EDITO-Model Lab is building an innovative solution through its on-demand, cloud-based What-if Scenarios (WiS). A key part of the European Digital Twin Ocean (EU DTO), our WiS can empower ocean and coastal stakeholders around the globe. In the case of the North Sea and Baltic Sea, EDITO-Model Lab’s WiS will allow local and regional end users to configurate high-resolution simulations on what is the likely response of specific measures aiming to control coastal hazards and the impacts of sea level rise.
Transformative Capabilities of Advanced Numerical Modelling
Central to this initiative is the HBMos (HIROM-BOOS Model - on-demand ocean modelling system), a two-way nested three-dimensional ocean circulation model. Unlike traditional one-way nested models, HBMos allows fine-resolution domains to exchange feedback with broader-scale models, enhancing both efficiency and accuracy. Developed by the Danish Meteorological Institute (DMI), HBMos incorporates an automated model builder and a user-friendly graphical interface, enabling stakeholders to quickly create simulations that meet their unique needs.
Key Features of HBMos:
- High-resolution Scalability: Supports resolutions as fine as 50 metres in select domains
- Operational Flexibility: Enables rapid deployment of sub-domain setups, reducing preparation time from months to mere days
- Robust Performance: Designed to manage complex coastlines and bathymetry with minimal manual adjustments
- Efficient High-Performance Computing: the model has gone through extensive code modernisation to reach an advanced performance on supercomputers
Enhancing Storm Surge Forecasting
The storm surge brought by Storm Babet in October 2023 underscored the numerical model’s potential. Affecting regions like Sønderborg, where narrow water passages complicate predictions, HBMos achieved markedly better results than traditional forecasting systems. This improvement is attributed to several factors, including its finer resolution (185 meters), the integration of a new bathymetry and coastline specifically designed for the Baltic-North Sea region, and the use of an ocean model tailored to local conditions. While weather forcing remained at a 2.5 km resolution, these enhancements allowed HBMos to reduce peak sea level prediction errors by up to 67% compared to existing Copernicus Marine and national forecast systems. Importantly, this achievement builds on the foundational data and capabilities provided by Copernicus Marine, showing the added value of EDITO-Model Lab in delivering on-demand, flexible implementations critical for emergency response and coastal management.
Seal level forecasts at Sønderborg during Storm Babet by using EDITO-Model Lab on-demand numerical model HBMos, Danish national forecasting system DKSS and Copernicus Marine Service forecasts based on NEMO-Nordic model.
Real-World Applications: Insights from Svendborg
Svendborg is part of a UNESCO Global Geopark in Denmark, vulnerable to coastal flooding. HBMos addressed key stakeholder concerns. During a workshop, municipal officials explored its potential for designing tide gauge networks, generating localised storm surge forecasts, and predicting seabed erosion in navigation channels. A tailored HBMos setup with a 50-meter resolution highlighted its ability to deliver actionable insights, earning positive feedback from local users.
The UNESCO Global Geopark in Svendborg. The red stars mark the locations of tide gauge stations.
Pioneering Coastal Risk Management
HBMos also supports advanced coastal risk assessments, such as analysing dyke breaching scenarios. In the aftermath of Storm Babet, the Oddemøse dyke in southeastern Denmark suffered breaches. By integrating HBMos outputs with the XBeach coastal morphology model, researchers successfully simulated this event, offering invaluable guidance for future dyke protection and maintenance.
Dyke breaching numerical modelling in Oddemøse in SE Danish coast during storm Babet. Left: XBeach model setup; lower right: the flooding caused by Oddemøse breaching; upper right: simulated coastal morphology evolution during storm Babet – the red point represents the location of the coast (land-sea interface), the dyke breaches in early morning 21 October and flooding reaches inland by around 350 m
Unlocking High-Performance Computing for On-Demand Models
The EDITO-Model Lab uses innovative cloud-based high-performance computing (HPC) infrastructure, including connection and interoperability with EuroHPC's centres as MareNostrum5. Scalability tests confirmed that two-way nested setups significantly reduce computational demands. For example, a 10-day Baltic-North Sea simulation - with main resolution of 1 nm being resolved by a 0.5 nm resolution within transition waters - requires only 1.1 node-hours, making high-resolution modelling both efficient and accessible.
HBMos two-way nested configurations for HPC scalability tests on EuroHPC MN5
Examples of HBMos HPC scalability tests on EuroHPC MN5 for a setup of 1 nm resolution in the Baltic-North Sea and 0.5 nm resolution in the Kattegat and western Baltic Sea. The command line activates the model directly on MN5, while singularity run activates the model from EDITO-Infra using cloud computing. The figure shows computing time used when running the model for 6 hours.
A Vision for Broader Impact
By combining scientific rigor with practical usability, the EDITO-Model Lab WiS can transform how coastal zone managers tackle current risks and plan for the future. With portability to other regions and compatibility with biogeochemical and coastal erosion models, this contribution to the construction of the EU DTO stands for a scalable solution to pressing global challenges.
Stay Connected: Engage with the European Digital Twin Ocean!
There is much more to explore within the two EDITO projects. Visit the EDITO-Model Lab and EDITO-Infra websites for further details, news, and results. Stay updated on the progress of the EU DTO by following our joint accounts on LinkedIn and X. Do not forget to subscribe to our new LinkedIn Newsletter and mailing list to receive exclusive insights, news, and updates. Several EDITO and EU DTO events are planned for 2025, where you will have the opportunity to explore, test, and contribute to the development of this groundbreaking tool. Stay tuned!
- Portability and interoperability of numerical models and simulation techniques
- Optimisation and adaptation to new and future computing platforms
- Coupling, interaction and hybridisation between different numerical models and Machine Learning components to represent ocean physics, biogeochemistry, biology and ecology
- Flexibility in use, configuration design and simulations to suit applications
- Virtual Ocean Model Lab is a co-development platform to connect developers of various models, users willing to produce simulations using AI and ML, and associated infrastructure providing access to different computing (HPC, CLOUD) and data storage and dissemination resources (data lake)
- Usage examples and user support for Focus Applications and What-if Scenarios