Europe's weather led to cold snaps in Greenland
Gustav Sjöholm/TT
Published 2024-09-20 05.45
Sustained heat waves over Europe produced a cold snap over the seas around parts of Greenland. It in turn affected one of the large glaciers.
- We saw that it melted less, says researcher Rebecca McPherson.
In north-east Greenland there are two enormous ice flows, which transport ice from the mainland out to the coast. These are Zachariæ Isstrøm and Ninety-nine Bræ, which is also called 79NG.
But the researchers have noted big differences between the glaciers. The Zachariæ Ice Tongue, the part that protrudes above the sea, completely collapsed in 2012.
- It was very dramatic. But 79NG has at the same time managed to keep its ice tongue, so obviously something happened there, says oceanologist Rebecca McPherson at the German Alfred Wegener Institute.
So why did one glacier melt so drastically – while its neighbor fared much better? To find the answer, McPherson and her colleague looked to what is happening in Europe.
Forces cold air down
During 2018 to 2021, so-called atmospheric blockages occurred over Europe. This means that a high pressure is locked over parts of the continent, which means that the low pressure does not come that way.
- When that happens, it forces more and colder air from the Arctic, which leads to the sea temperature dropping. But it also slows the inflow of warm water from the Framsund between Greenland and Svalbard.
As the colder water slid under 79NG's ice, it slowed the melt.
Continued problems
Four years is not much in the life of a glacier, which is normally measured in decades. In the long term, the ocean is warming as a result of climate change, and 79NG is expected to continue to melt and contribute to sea level rise and risks changing ocean movements.
- We still see this significant long-term warming trend in the Western Spitsbergen Current, which has warmed almost a full degree in the last 25 years, says McPherson.
Gunilla Svensson, professor of meteorology at Stockholm University, thinks it is interesting that the study shows the connection between the atmosphere, the sea and the glaciers.
The hope is that the study will lead to better forecasts for glacier melting.
- We need more observations to understand how these processes work, so that we can improve our models to really understand how the systems are connected and how they can change in the future, she says.
FACTS
The ice in Greenland
In recent decades, the ice on Greenland has decreased, as a result of a warmer climate and the warming of the sea. The melting ice is so extensive that it contributes to raising sea levels.
The two largest glaciers in northeast Greenland are Zachariæ Isstrøm and Nioghalvfjerdsfjorden (79NG).
The researchers have studied 79NG and the nearby waters between 2018 to 2021, where they see a connection between colder sea water, decreasing melting and so-called atmospheric blocking over Europe.
The study is published in the journal Science.
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Sharp reduction of Kebnekaise's south peak
Hanna Rasmusson/TT
Published 2024-09-20 07.26
On September 15, staff at Stockholm University's research station in Tarfala carried out the annual measurement of Kebnekaise's southern peak. This year, the height was measured at 2089.9 meters above sea level, a decrease of 3.3 meters compared to last year's measurement.
"This year's melting of 3.3 meters is the strongest in three decades," says Nina Kirchner, professor of glaciology and director of the Tarfala research station in a press release.
The month of August was significantly warmer than usual – with an average temperature of 9.1 degrees measured at the research station. During the last ten years, the average temperature has been 6.5 degrees in August. That could explain this year's melting is twice as big compared to observations over the past decade, according to Kirchner.
Nordtoppen, which has an ice-free mountain top, is Sweden's highest point for the sixth year in a row. Now it is 6.9 meters higher than the southern peak.
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