Category: Press release

A major advance to predict future changes in marine ecosystems

Climate change affects everything from bathing temperatures to fish health and seafood safety. Many countries along the Atlantic Ocean rely on fish and seafood as their primary food source. Researchers have now taken a significant step closer to an operational climate warning system for the ocean.

By Tori Pedersen, Bjerknes Centre for Climate Research 

– This is an important first step. It is really exciting, says Professor at the Geophysical Institute and Bjerknes Centre, Noel Keenlyside.

Keenlyside leads the EU-funded TRIATLAS-project. To predict future changes in marine ecosystems, you need to run many computer simulations. Traditionally only institutions with sufficient financial and technical resources could manage this. But now the project has introduced a possible solution to use simple and free technologies to allow any modelling group to perform these exercises. The new method is also a significant breakthrough when it comes to time efficiency. Previously, running such marine ecosystem model would have taken weeks, but now it can be completed in 30 hours.

– This is a major breakthrough. To achieve this we needed to bring marine ecosystem and climate modellers together. This can become a powerful tool for managers and policy makers”, says Keenlyside.

 

Easier to predict changes 

When the global temperatures rise, the temperature in the ocean also increases. And as the amount of CO2 in the atmosphere rise, so does the amount of CO2 in the ocean. A warmer ocean will make species migrate to find conditions they prefer. By making marine ecosystem models more accessible, it will be easier to predict how the ocean will change in the future. 

Jeroen Steenbeek, researcher at the Ecopath International Initiative led this work in the TRIATLAS project. He explains the progress as follows.

– By constructing the “MacGyver” framework from simple and open-source tools we basically allow any ecosystem modeller, around the world, to better assess their models for policy advice, without the need for IT skills or expensive hardware.  

In this video, you can learn more about how climate models can be combined with ecosystem models to improve the prediction of marine ecosystems.

Make the model operational 

According to Steenbeek, lack of robustness assessments has hampered the uptake of the Marine Ecosystem Models in the policy and decision-making arenas, where they are needed. But amongst the challenges now is how to make the model operational, so that it becomes useful.

– The availability of new capabilities inevitably raises new questions for which the Marine Ecosystem Models community is not yet prepared. The framework now allows Marine Ecosystem Models to run hundreds of times, but making sense of the terabytes of data that comes out of these runs is a challenge that requires a theoretical framework that does not really exist yet.

The result was produced through very collaboration and interdisciplinary efforts within the TRIATLAS project and included the Norwegian Climate Prediction Model. The new approach is to use complex numerical models of the marine ecosystem. These models include complex interactions in the marine ecosystem and also the influence of environmental factors and fisheries. The new models can be used to investigate how climate and fisheries could influence marine ecosystems over the next few years. 

The way forward

Financed by the EU, TRIATLAS aims to study the current situation of the Atlantic Ocean`s marine ecosystem and predict future changes. According to Keenlyside this new result in the project will benefit the scientific community, fishery managers and people who plan how to use ecosystem services. For the moment, this has been developed for the South and Tropical Atlantic, but the prediction system is based on global models. Thus, this approach can be used everywhere. However, there is still a lot more work to be done.

According to Steenbeek there are two things that are important going forward. The first thing is to further develop and mature the framework in close collaboration with the global Marine Ecosystem Models-community, and at the same time work with global initiatives such as The Fisheries and Marine Ecosystem Model Intercomparison Project to develop and mature the statistical tools to digest the massive amounts of data, and to start the work to make the process of modelling for policy more robust.

– These are the first results from the system, and there is still quite a long way to go before they will be operational. However, there is a great potential here and I see this opening a new area of active research”, says Keenlyside.

Reference: 
Jeroen Steenbeek, Pablo Ortega, Raffaele Bernardello,Villy Christensen, Marta Coll, Eleftheria Exarchou, Alba Fuster‐Alonso, Ryan Heneghan, Laura Julià Melis, Maria Grazia Pennino, David Rivas and Noel Keenlyside
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2023EF004295

 

New moorings deployed to strengthen the South Atlantic observing system

An international effort enhances knowledge of currents and ecosystems in a data-sparse region of the global ocean.

To extend a network of observations in the South Atlantic Ocean, two new scientific, full-depth, instrumented moorings have been deployed off the eastern coast of South America. These tall moorings will measure variations in the Atlantic circulation – a system of ocean currents affecting life in the ocean as well as the weather and economy of coastal nations.

The Atlantic Meridional Overturning Circulation (AMOC), consisting of an upper-ocean northward flow compensated by a southward deep-ocean flow, is a main engine of the Earth’s climate system. This upper AMOC cell is connected to deep-water formation and sinking in the subpolar North Atlantic and upwelling in the Southern Ocean. Beneath the upper cell is a weaker abyssal cell, sourced by the sinking of dense water near Antarctica.

With global warming the system is thought to become weaker. As well as such long-term circulation changes, natural variations on shorter timescales occur. These may be due to reductions of sinking water in the north, but also to changes in the water mass exchange in the south.

SAMOC/SAMBA mooring deployment
Deployment of the moorings in the southwest South Atlantic from the ARA Austral research vessel in December 2022.
Image credit: Michele Baqués.

“The South Atlantic is particularly important,” says Peter Brandt, professor at the GEOMAR Helmholtz Centre for Ocean Research.

“Changes in the AMOC that result from water mass exchanges between the Atlantic and the Indian and Pacific oceans, can best be detected in the south, and then compared to changes originating in the well-observed North Atlantic,” he explains.

Peter Brandt
Peter Brandt from GEOMAR and TRIATLAS emphasizes the importance of contributing to international data collection. Image credit: Ellen Viste / TRIATLAS

“The South Atlantic is the only ocean basin with a net equatorward heat transport, and where freshwater transports may be key to AMOC stability. It is also the basin where the upper and abyssal overturning cells of the AMOC are both important,” adds María Paz Chidichimo, leader of the research involving the new tall moorings.

Chidichimo is a researcher at the Argentine Scientific Research Council (CONICET), the Hydrographic Service and the French-Argentine Institute for Climate Studies, CNRS/IRD/CONICET UBA UMI 3351 IFAECI, in Buenos Aires.

María Paz Chidichimo
María Paz Chidichimo from the EU Horizon 2020 project iAtlantic leads the scientific work related to the moorings. Credit: Private

The new moorings contribute to an existing measurement array along 34.5 degrees south on both sides of the Atlantic Ocean, termed South Atlantic MOC Basin-wide array (SAMBA). The SAMBA array is a component of the multi-national South Atlantic Meridional Overturning Circulation (SAMOC) Initiative, established in 2007 to measure ocean currents and the transport of heat and salt at key locations in the South Atlantic Ocean.

While existing measurements in the southwestern Atlantic are to a large extent performed using echosounders situated on the sea floor, the new moorings will directly measure seawater properties throughout the water column, from the seafloor up to the surface.

Data for the future

“We are proud to contribute to the long-term efforts to maintain and develop the global observing system,” says Peter Brandt.

He emphasizes that the goal is to measure changes in climate through the coming decades, not only within the timeframes of a single research project.

The moorings were deployed by the EU Horizon 2020 sister projects iAtlantic and TRIATLAS, contributing to the fulfillment of the Belem Statement – a joint declaration on Atlantic research between the European Union, Brazil and South Africa – as well as bilateral agreements between the European Union and Argentina, and with other countries.

Configuration of the SAMBA-West array in the SW Atlantic: PIES NOAA USA (black triangles), CPIES USP Brazil (yellow circles), ADCP mooring USP Brazil (blue diamond), and recently deployed iAtlantic (iA) and Triatlas (Tr) tall moorings EU, CONICET-SHN Argentina, GEOMAR Germany (magenta squares). PIES/CPIES site names on the transport line are displayed. White circles represent the nominal positions of the hydrographic CTD/O2/LADCP stations (some stations are not displayed for clarity). [Bathymetry (shaded background) comes from the Smith & Sandwell (2007) data set]. The arrows on top represent the surface and sub-surface circulation of the Brazil Current (red) and Malvinas Current (light blue) and the deep circulation of the Deep Western Boundary Current (purple). PIES: Pressure-recording Inverted Echo Sounders. CPIES: Current- and Pressure-recording Inverted Echo Sounder
Figure: María Paz Chidichimo.

Influencing climate, weather and ecosystems

The South Atlantic has received far less observational effort than the North Atlantic during recent decades. The lack of sufficient physical oceanography information near the coasts also limits our understanding of marine ecosystems.

María Paz Chidichimo emphasizes the need to enhance oxygen measurements in tandem with physical measurements to better track water masses and evaluate changes relevant to ecosystems in the South Atlantic.

“Continuous full-depth observations are critical to detect and understand combined variations of ocean currents and physical and biogeochemical water mass properties associated with climate change,” she says.

She hopes the new moorings will shed light on the impacts of western boundary currents and the AMOC on regional weather, climate, ocean extreme events and sea level, as well as on the content of heat, salt and oxygen in the water. These properties influence ecosystems, marine resources and ocean health.

“The new observations will improve the capacity to model some of the changes and improve predictive tools in a region where full-depth continuous in situ observations are sparse,” says María Paz Chidichimo.

Axel Toledo (SHN/UBA), Christian Begler (GEOMAR), Sebastian Perez (Austral), Fabio Colman (SHN) and Wiebke Martens (GEOMAR) preparing the floats that provide mooring floatation.
Image credit: Alberto Piola

Projects involved

iAtlantic

iAtlantic is a multidisciplinary research program seeking to assess the health of deep-sea and open-ocean ecosystems across the Atlantic Ocean. 

The project is financed by the EU Horizon 2020.
Coordinator: Prof. Murray Roberts, The University of Edinburgh
Deputy coordinator: Colin Devey, GEOMAR

https://www.iatlantic.eu

TRIATLAS

Tropical and South Atlantic Climate-Based Marine Ecosystem Prediction for Sustainable Management

Research project financed by the EU Horizon 2020, lasting until November 2023 
Coordinator: Prof. Noel Keenlyside, UiB and the Bjerknes Centre for Climate Research 
Co-lead: Dr. Heino Fock, Thünen Institute

https://triatlas.w.uib.no 

SAMOC Initiative

The South Atlantic Meridional Overturning Circulation (SAMOC) Initiative is a group dedicated to advancing our understanding of the role of the South Atlantic Ocean in the meridional overturning system and the establishment of an observing system to capture key components of the circulation.

SAMOC/SAMBA contacts for the work described:
Dr. María Paz Chidichimo
Prof. Peter Brandt 

The South Atlantic MOC Basin-wide array (SAMBA) array at 34.5°S in the Southwest South Atlantic is funded by: SAM project (NOAA-AOML/NOAA-GOMO, USA); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Servicio de Hidrografía Naval (SHN) (Argentina); SAMBAR project (Oceanographic Institute of the University of São Paulo, Brazil); GEOMAR Helmholtz Centre for Ocean Research Kiel (Germany), iAtlantic and TRIATLAS.

https://www.aoml.noaa.gov/phod/SAMOC_international/index.php