Digital Twins of the Ocean: a unified technological approach to understand, manage, and preserve our future

Pedro Jorge

  (1)INESC TEC & Faculty of Sciences of the University of Porto

Artur Rocha


The oceans are the main regulator and stabilizer of the planetary ecosystem and its primary source of life.

Presently, many factors associated with human action (rising temperature, acidification, overuse of plastic…) are putting the homeostasis of such complex system at risk, seriously compromising the future habitability for humans and other species. In this context, we need to monitor a diversity of physical and chemical parameters at a global scale, to better understand, and learn to modify our actions in ways that promote the natural balance and regeneration capability.

Ocean monitoring presents a diversity of challenges, starting from its vastness and dynamic nature, imposing the need for technological solutions that can cope with very demanding requirements. Continuous monitoring, covering large areas and a variety of depths, over extended periods of time, and measuring a multiplicity of parameters, such as temperature, pH, biodiversity or plastic content, requires a diversity of technologies, able to sustain performance under harsh conditions, and capable of gathering, storing and sometimes conveying huge amounts of data. It adds to this the huge logistic difficulties and costs of deployment, operation and maintenance.

Considering the diversity of operational requirements, a large variety of solutions is being explored, both in what concerns the deployment platforms and sensing technologies.

While satellites enable remote planetary coverage, the cost and deployment challenges of such platforms are very high. In addition, their efficacy strongly relies on the development of more capable instrumentation, and present efforts include, for instance, developing sensors with wider spectral coverage, and strategies to circumvent atmospheric interference.

In this context, a large global initiative is in place to enable widespread development of Pico and nano satellites, standardise small-sized (<10kg) cube shape platforms, deployable at affordable prices, opening new possibilities for rapid technology testing, and increased participation in space missions by developing nations, small companies, and educational institutions.

Surface and underwater monitoring are more challenging, particularly in what concerns spatial and temporal coverage. For these reasons different platforms and sensing technologies are needed. Continuous monitoring of physical, chemical, and biological parameters in the marine environment over extended periods requires permanent or long-term operating systems.

Permanent ocean observatories include fixed subsea observatories, moored buoy systems, coastal monitoring stations and deep-sea observatories, and are often localized in strategic regions, providing focused monitoring rather than comprehensive coverage. Indeed, even if a growing number of such infrastructures is installed, the ocean area covered by permanent observatories is still relatively small in the context of the vastness of global oceans.

In this regard, mobile autonomous or drifting platforms, such as gliders and drifters, enable the coverage of much larger areas. The latter are buoyant instruments that move passively with the ocean currents, while the former are autonomous vehicles designed to move through the water column by adjusting their buoyancy. In addition to these, larger mobile autonomous platforms, such as landers, are a new and promising tendency that can enable reconfigurable observatories, that can actively get data from where it’s most needed.

Ultimately the quality of collected data relies on the reliability of the sensor technology. Most common sensor technologies used include, acoustic, CTD (conductivity, temperature and depth), dissolved oxygen, fluorometry (indirectly measuring chlorophyll), and a diversity of detectors for optical properties such as turbidity, irradiance, absorption and scattering, from which different properties of the ocean waters can be inferred.

Present tendencies include miniaturisation of sensor technologies, enabling new functionalities such as automatic collection of samples for e-DNA analysis and multiparameter sensing. More robust and compact optoelectronics, coupled with advanced machine learning are empowering spectroscopic analysis such as plasma spectroscopy, hyperspectral or holographic imaging. Furthermore, the fusion of information from several platforms and/or sensors, coupled with artificial intelligence is greatly improving the quantity and quality of information that can be extracted from the data.

The creation of digital models is particularly relevant,, materialising a platform where information can be integrated, interpolated and/or extrapolated, eventually bridging the gaps of the physical layers, and enabling a more holistic approach to the study of the ocean ecosystems.

Hence, a Digital Twin of the Ocean (DTO) can leverage on existing science assets to provide consistent high-resolution, multi-dimensional descriptions of the ocean, and to unravel its underlying processes.

The DTO aims at being a place of digital co-creation, bringing together different disciplines and communities. It benefits from IoT data collection and transfer, including novel sensors, Big Data analytics and Artificial Intelligence tools.

Digital twins shall make use of real-time and historical data to represent the past and present, as well as models to simulate future scenarios and support decisions about human interventions on the ocean.

The DTO is an asset that aims at servicing multiple types of users, such as researchers, entrepreneurs, decision-makers and citizens alike. As an example, researchers will be able to use the DTO to predict how climate change and human activity will affect marine ecosystems. Based on this knowledge, decision-makers will assess different management plans to choose the most efficient one.

In the same manner, entrepreneurs will be able to use this asset to plan their activities at sea, accelerating the implementation of marine renewable energies, optimizing production and minimising negative impacts.

Last but not least, citizens are a vital part of this digital ecosystem, they will be able to contribute to biological and ecological observation campaigns which can be used to improve models. These models can then be applied for other purposes such as generating alerts for extreme weather events, predicting local jellyfish blooms, or identifying safe and clean swimming spots.

Beyond the wealth of high-quality data, the DTO will also make scientific state-of-the-art models representing different components of the ocean system more accessible and easier to combine, enabling transdisciplinary scientific approaches, revolutionizing work practices, and helping to make science-based, informed decisions. The completion of these scenarios heavily relies on a well-planned and maintained network of multiples observational platforms, overlayed with an effective communication network, and a powerful computational capability.

The challenges at hand require substantial critical mass in terms of technology, financial support, and political engagement. For these reasons, most relevant initiatives are promoted either by governmental agencies of large rich countries or private-non-profit organisations. In both instances, they tend to operate at an international level, tackling not only the technological problems but also socio-economic and environmental sustainability, influencing policy making and promoting public knowledge and initiatives. These initiatives should also be fostered and promoted, at a private level because such a global challenge can only be met by a united global response. It is time to unite or perish.