The e3HOPE service: a high-resolution forecasting system for the hydrodynamics in Fangar Bay (Ebro Delta, NW Mediterranean Sea)

The Ebro Delta (EU Natura 2000 site and Natural Park and Biosphere Reserve (UNESCO)) is a complex area that faces a set of challenges mainly due to anthropogenic pressure and climate change related risks. The two Ebro embayments (i.e. Fangar and Alfacs) are natural protected areas of value for the survival of many species, such as the critically endangered Pinna nobilis. Likewise, these bays are two of the most productive aquaculture areas along the NW Mediterranean Sea.

The e3HOPE Service, led by NOW Systems (Nologin), provides a coastal operational forecast for the Ebro Delta. The system is based on a coastal downscaling of the Copernicus Marine Mediterranean regional solution, generating daily forecasts at 350 m resolution for the whole Ebro Delta and products at even higher resolution (around 70 m) for the Fangar Bay. A high-resolution ROMS model application, developed and tested by the LIM/UPC and integrated into the NOW operational framework, contributes to a seamless modelling in the area, filling the gap between the existing Copernicus regional forecast products and the local needs for a higher resolution model prediction.

The e3HOPE coastal service is completed with a tailor-made visualization service layer co-designed with IRTA. The new NAUI web service deployed by NOW for the Delta and Fangar Bay is a highly customizable tool that allows visualization of both met-ocean observations (including additional local monitoring routinely performed at specific fixed CTD stations) and the e3HOPE model forecasts at selected locations. This new NAUI deployment at the Ebro Delta certainly eases, and enhances, the IRTA uses of (new and existing) operational forecasting capabilities, making coastal data more actionable and transferred into fit-for-purpose applications for management, supporting sustainable aquaculture activities and biodiversity conservation.

This contribution is mainly focused on the skill of the current e3HOPE model release, being the model solution validated along 1 year with available in-situ observations (for temperature, salinity, sea level and surface and bottom water currents). Some insights into the operational forecast products delivered by the e3HOPE service, as well as into the planned service evolution (for 2024) is provided. Next e3HOPE operational release will include: (i) upgrade of the model system (to a wave-current coupled system, using COAWST), (ii)  improvement of the fresh water forcing (substituting climatological approaches by predicted data for the Ebro river, and some local channels discharges), and (iii) improvement in the initialization (using CTD data), in the Fangar Bay domain.