The Cretan Sea oil spill Digital Twin pilot for the ILIAD Digital Twin of the Ocean
Authors: Spanoudaki Katerina , Kozyrakis George , Metheniti Vassiliki , Parasyris Antonios , Kampanis Nikos 
Published: February 2023

The world&#8217;s oceans have been studied and monitored for many decades to enhance our understanding. In today&#8217;s world, with the explosion of new data provided by many different Earth observation sources and the availability of advanced computing infrastructures (cloud computing, HPC, IoT, Big Data), creating a digital representation of the ocean is becoming a reality. The EC recently funded the H2020 ILIAD project, which aims at establishing an interoperable, data-intensive Digital Twin of the Ocean (DTO). The ILIAD DTO will integrate real-time sensing of ocean variables, state-of-the-art high-resolution models, modern data analytics and digital infrastructures to create virtual representations of physical processes and understand their behaviour, anticipating and predicting their response to simulated events and future changes. ILIAD will enable an ecosystem of interoperable DTOs, integrating the plethora of existing EU Earth Observing and Modelling Digital Infrastructures. It will fuse a large volume of diverse data and will enhance ocean data infrastructures with additional observation technologies and citizen science.&#160; ILIAD will provide a virtual environment representing the ocean, capable of running predictive management scenarios and will utilize Big Data analytics for forecasting of spatiotemporal events and pattern recognition. Several DT pilots will be undertaken in several key thematic areas such as offshore wind energy, wave and tidal energy, biodiversity assessments, marine pollution and more.&#160;The current work presents ongoing activities for a coastal, high-resolution Digital Twin pilot for Cretan Sea, to be demonstrated in the frame of ILIAD project. The pilot focuses on oil spill pollution monitoring and forecasting. The DT environment combines high-resolution forecasting services based on numerical weather (WRF), hydrodynamic (NEMO), sea state (WAVEWATCH III) and particle tracking models (MEDSLIK-II), enhanced by the integration of &#160;Sentinel data and real-time observations from novel, low cost current and waves meters, drifting trackers, as well as citizen science. WRF model is applied for forecasting of meteorological variables at&#160; &#820; 3 km resolution by dynamic downscaling of coarser resolution climatic modelling forecast data (NOAA&#8217;s GFS). This way, higher computational accuracy is achieved over Cretan Sea, thus revealing finer wind scales phenomena. The downscaled weather forecasting data are used to force NEMO and WAVEWATCH III, to obtain high-resolution forecasts of important marine parameters, such as sea currents, temperature, salinity and waves over a fine grid of&#160; &#160;&#820; 1 km for the coastal area of Crete. For oil spills, the DT of Cretan Sea will integrate operational analysis of Sentine-1 images, triggering MEDSLIK-II oil spill model once an oil spill event or anomaly is identified. Adjusting forecasts to observations by reinitialising the model with updated observational patterns will contribute to the forecast error growth being implicitly accounted for and minimized. The pilot DT virtual environment will allow on-demand simulations of predictive scenarios of oil spill events and response strategies. &#160;The aim of the Digital Twin is to aid the immediate response in case of accidental oil releases, minimize the damage and reduce the time for environmental recovery.Acknowledgement: This research has received funding from the European Union&#8217;s H2020 RIA programme under GA No 101037643.