When oceanographer Toste Tanhua and his research team set up a trial system to monitor aquaculture conditions near Barcelona in 2023, they were keenly aware of the havoc a powerful storm had wreaked on the region three years earlier.
Storm Gloria ravaged southeast Spain in January 2020, killing 13 people and causing millions of euros in damage. At the Port of Barcelona, seven-metre waves crashed over sea defences, engulfing nearby coastal towns in sea foam and ravaging beach resorts.
“We had Storm Gloria very much in mind,” said Tanhua, a chemical oceanographer at GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany. Tanhua has personally taken part in over 35 marine research expeditions, including in the Arctic, Atlantic and Antarctic.
Ocean gaps
The disaster in Spain highlighted the need to improve Europe’s ocean monitoring and warning systems. Despite the fundamental importance of the marine environment, both environmentally and economically, there are still large gaps in ocean observation and forecasting systems.
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Now we are seeing a need for a sustained observing system that can deliver information for understanding ocean health, biodiversity changes and the effects of climate change.
Ocean observation is “big science”, involving large teams and resources. The EU has made significant investments in recent decades to boost the development of ocean observation and improve integration and coordination of national efforts.
Tanhua has been heading up an international team of researchers working to help integrate European national ocean observation systems into a global system.
As part of a four-year EU-funded research initiative called EuroSea, which concluded in December 2023, the researchers brought together experts from 56 organisations across Europe and beyond.
Those included the Global Ocean Observing System (GOOS), World Meteorological Organization, the international organisation Mercator Ocean International, and the European Global Ocean Observing System (EuroGOOS).
International oversight
EuroSea is part of a series of scientific efforts that supported the development of the EU’s Copernicus Marine Service (CMS).
This service is the marine component of the EU’s Copernicus Programme and provides free, authoritative information in support of European and international ocean management policies.
Its aim is to shed light on important changes taking place in and around the world’s oceans, from ocean and weather forecasting to picking up on longer-term climate and ecosystem signals.
Historically, ocean science has been driven by curiosity, as people wanted to explore the oceans and their life forms, said Tanhua.
“Now we are seeing a need for a sustained observing system that can deliver information for understanding ocean health, biodiversity changes and the effects of climate change,” he said.
Such operational services are needed for shipping and other maritime industries such as aquaculture, offshore wind and tourism.
Long-term effort
The origins of the CMS go back to an earlier EU-funded research initiative called MERSEA-STRAND 1. The research team carried out an analysis of the strengths and weaknesses of European operational oceanography and data assimilation systems back in 2003 and 2004.
“This was when all the operational oceanography centres in Europe first sat down together to discuss how to develop a fully operational system for ocean modelling and forecasting,” said Pierre-Yves Le Traon, scientific director of Mercator Ocean International.
This paved the way for a series of EU-funded programmes that worked to integrate satellite observations with data from in-situ monitoring networks for more precise ocean modelling, eventually leading to the creation of the operational CMS in 2014.
“We need Copernicus’ capabilities to better manage the ocean in a sustainable way, support the development of the blue economy and better protect marine ecosystems,” said Le Traon.
He also stressed the need to better understand how the ocean is being altered by climate change to predict its long-term evolution, and to prepare and adapt.
Improving data quality
Tanhua and the EuroSea research team explored ways to connect data from many different sources to enhance overall data quality in EuroGOOS.
In addition to the aquaculture monitoring site off the coast of Spain, the researchers also set up a similar data collection service in the Irish Sea to support Irish fish farmers. In both cases, the researchers were responsive to user needs.
In Ireland, data collection was mostly concerned with monitoring ocean health, measuring things such as oxygen levels and the presence of harmful algal blooms. These were connected to levels of nutrients in the water and heat waves.
In Spain, they were more interested in understanding waves and currents and wind, said Tanhua. “They wanted a warning system that would allow them to prepare for adverse weather conditions.”
In both sites, the team used buoys equipped with sensors to measure both chemical and physical ocean variables. These measurements were combined with data from other observation systems in the Copernicus network.
In Spain, the oceanographers also worked with several ports around Barcelona. The data the buoys collected allowed them to model how currents and wave conditions would change in ports and beaches along the Catalan coast during storms.
It also provided information on how marine construction projects could alter tides and storm surges, and even insight into where the coast guard should search in the case of someone falling into the sea, based on local ocean currents.
Solar-powered drone
Tanhua specialises in ocean ventilation – the movement of water from the surface of the ocean into the depths, carrying with it properties such as changes in temperature, gases like carbon dioxide and oxygen, or fresh water from rain.
With the EuroSea research experiments, the team was able to gain further insight into this process, with all its environmental implications. “There was a function that allowed you to model how an oil spill would disperse, for example,” said Tanhua.
The researchers used an autonomous sailing drone to measure carbon dioxide concentrations on the ocean surface in the tropical Atlantic.
“Oceans are currently taking up about a quarter of man-made carbon dioxide emissions,” said Tanhua. This amounts to an estimated 10 to 12 billion tonnes of carbon dioxide per year, or about a third of annual global carbon dioxide emissions from fossil fuels and industry.
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We need Copernicus’ capabilities to better manage the ocean in a sustainable way.
To accurately predict the impact of climate change on the world’s oceans, scientists need to understand these carbon dioxide fluxes better.
The solar-powered drone equipped with a carbon dioxide sensor spent more than a year at sea, travelling around 22 000 kilometres back and forth across the Atlantic Ocean.
The idea was to explore how carbon dioxide concentrations could be measured. The project also used carbon dioxide sensors on buoys and cargo ships, and robotic floats that drift with ocean currents.
The sensors use data from the Copernicus system to improve forecasting, but they also send data back to the system, enhancing its capabilities.
Digital twin
Building on the achievements of the CMS and the European Marine Observation and Data Network, scientists are now developing the European Digital Twin of the Ocean (EU DTO), using the latest advances in observation, modelling and artificial intelligence.
The first pre-operational platform of the EU DTO was unveiled in June 2024.
The digital twin platform uses real-time and historical ocean data and models to run different “what if” scenarios, explained Le Traon.
“What if I reduce the pollution in a given river, what would be the impact on the ocean?” he offered as an example. “Given different scenarios of climate change, what will be the impact of sea level rise on the coast?”
“Being able to model such climate change scenarios will help decision-makers better manage the ocean,” Le Traon said.
Research in this article was funded by the EU’s Horizon Programme. The views of the interviewees don’t necessarily reflect those of the European Commission. If you liked this article, please consider sharing it on social media.
