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Optimized Alarm Helps Mitigate Changes in European Climate

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Jul 16 2020

Laura Jackson and Richard Wood, both climate scientists from The Met Office in the United Kingdom, have detected metrics that may provide early warnings of sudden variations in the European Climate.

The study is part of the European (EU) Horizon 2020 TiPES project managed by the Niels Bohr Institute at Denmark-based University of Copenhagen.

Establishing early warning systems—the so-called climate alarm device—is a major objective in climate science. Such systems are important for tracking sudden variations in the system of sea currents in the Northern Atlantic Ocean.

Such currents, called the Atlantic meridional overturning circulation (AMOC), comprise the Gulf Stream that delivers upper ocean waters northwards in the Atlantic. In this case, the currents become denser and colder and sink subsequently.

During the process, the AMOC conveys heat to the coasts of Northwestern Europe and keeps the continent relatively warmer than similar landmasses existing on the same latitudes.

Based on the analysis of previous climates, it has been clearly documented that massive and abrupt temperature changes had taken place both in and around the North Atlantic. Such temperature changes are believed to be triggered by the movement of AMOC suddenly between weaker and stronger states by traveling across tipping points.

Although AMOC is not expected to collapse in the next century, it would have a major effect on society; hence, one should be prepared to detect the tipping signals in a timely manner to alleviate or prepare for sudden changes in the AMOC.

One query to address in that scope of work is which kind of metrics should activate the alarm system?

The scientific article titled “Fingerprints for early detection of changes in the AMOC” presently helps researchers to clarify this significant query.

Based on climate simulations, the study has been published in the Journal of Climate and penned by Laura Jackson and Richard Wood from the UK-based Met Office as part of the EU Horizon 2020 TiPES project.

We show, that using metrics based on temperatures and densities in the North Atlantic in addition to continuing to directly monitor the AMOC can improve our detection of AMOC changes and possibly even provide an early warning.

Laura Jackson, Climate Scientist, The Met Office

Furthermore, the study’s authors concluded that using numerous metrics for tracking purposes is crucial to enhance detection.

A couple of systems directly track the AMOC. The RAPID array spans from the Florida Strait to the west coast of Northern Africa, and the OSNAP array runs from Labrador in Canada to the Greenland tip on to the west coast of Scotland. Current observing systems are also in place that help track the density and temperature metrics.

Still, it is difficult from these measurements to tell whether a change in the AMOC is from natural variability that takes place across decades, from a gradual weakening because of anthropogenic climate change, or from crossing a tipping point.

Laura Jackson, Climate Scientist, The Met Office

To put this in simpler terms, the alarm is not fully developed and no one knows exactly which type of changes to anticipate, if it happens to go off.

This means more science is required. And one suitable way to do this is to assess the existing metrics in competing climate models to predict the strength of the results from the present study.