An international research team led by the University of Galway has developed what it says is a “crucial new way” to enable scientific reconstruction of ocean acidity and CO2 levels in cold polar oceans.
The method offers new insights into climate change, according to the research published in the scientific journal Biogeosciences.
The scientists studied how tiny polar foraminifera plankton record ocean acidity (pH) in their shells.
“When these organisms die and sink to the ocean floor, their shells form part of the ocean’s natural climate archive, which can be studied when collecting sediment cores from the seabed,” the team explains.
In both hemispheres, polar seas are areas of strong deep-water formation which play a major role in the storage of CO2 and the Atlantic Meridional Overturning Circulation (AMOC) – the conveyor belt of marine currents that keep Northern Europe, in particular Ireland and Britain, relatively mild in winter.
Scientists have warned that AMOC is at risk of being disrupted due to rapid global warming.
The ultimate threat is that a weakening or collapse of the AMOC triggers extreme weather events and disruptive changes in seasonality across Europe.
The new findings now allow scientists to go back in time to test whether the rate at which CO2 is removed from the atmosphere is reduced when the AMOC slows down.
These and other findings and policy issues were discussed at the third Annual Irish AMOC meeting in the University of Galway this past week.
Project senior researcher Dr Audrey Morley said the analysis of the tiny polar foraminifera “has opened a door to answer questions about climate change which were previously unavailable”.
“ We can use our new method to look at the acidity of the polar surface ocean and how it changed over time. That also gives us a deeper understanding of how the AMOC controls our climate,”she said.
The third Annual Irish AMOC meeting is hosted by the Ryan Institute at University of Galway and is co-organised with Maynooth University and Met Éireann.
It brings together leading researchers, state agencies and policymakers to discuss latest research findings and future priorities for AMOC research in Ireland.
The new research is available here