A ‘blue spot’ in the North Atlantic Ocean has slowed the melting of Icelandic glaciers, a new study has found.
Various explanations for its erratic temperature have been offered, but the mysterious cold water sheet just south of Greenland has puzzled scientists for years.
It has been linked to a weakened ocean current in the North Atlantic that typically brings heat from the tropics. Research from 2020 also revealed that other man-made factors are at play, including the formation of “low-level clouds” above the drop that deflect sunlight.
Now a new study, published in Geophysical Research Lettersshows how the Blue Spot has dampened atmospheric warming in Iceland since 2011 and reduced glacier melt.
The correlation between the formation of the Blue Spot and the less drastic loss of Icelandic glaciers was a surprising finding for the Icelandic and Dutch research team, lead author Brice Noël told Euronews Green.
The Surprising Relationship Between Iceland’s Glaciers and the Blue Spot
Since the end of the Little Ice Age in the late 1880s, Icelandic glaciers have been losing mass.
When less snow falls on a glacier in winter than is lost when it melts in summer, it leads to something called negative surface mass balance (SMB). This ultimately causes sea level rise.
The rate of loss accelerated in the 21st century, but researchers were intrigued to find that it had slowed considerably from 2011. This is not the case for the surrounding Arctic titans. The Greenland Ice Sheet is largest contributor to sea level riseexcretion 166 billion tons of ice in the year until August 2021.
The blue spot is also an anomaly. While global temperatures have risen by an average of 1°C over the past century, the gout – also known as the “warming hole” – has dropped by 0.9°C.
The more researchers studied it, the more certain it seemed that there was a link. Since Iceland is more exposed to oceanic and maritime influences than Greenland, it appears that colder air convection from the Blue Spot kept its glaciers more intact.
“It really shows that you have these interactions between land, ice, atmosphere and ocean,” says Noël, a post-doctoral fellow at the Institute for Marine and Atmospheric Research in Utrecht.
“And all of these elements combined can create a kind of feedback mechanism that slows down mass loss, but unfortunately only for a temporary moment.”
The loss of Iceland’s glaciers is expected to accelerate again from the 2050s
According to the team’s climate modeling — which takes into account satellite observations and fieldwork — there will be a very brief period in the late 2040s when these glaciers actually revert to zero SMB. But by the mid-2050s, global warming will reverse the narrative.
Once the blue drop stops cooling, the ice will begin to melt even faster than it can be replaced. By the end of the century, scientists estimate that these glaciers will lose a third of their total volume – with disastrous consequences worldwide if climate change is not curbed.
“The Arctic is warming rapidly, and it can be difficult to live with it,” Noël says, “but climate projections give us trajectories that allow us to see what needs to be done to try to mitigate the melting of glaciers. “