In the Last Ice Area, above Canada's Ellesmere Island, a polynya grows. Due to strong, anticyclonic winds from the Arctic, the gap in the ice remained open for approximately two weeks in May 2020.
New research revealed that a huge hole was created in the Arctic's thickest, oldest ice in May 2020. Scientists had previously believed that this region of Arctic ice was the Arctic’s most stable. However, the huge rift indicates that the old ice is susceptible to melting.
The first observation of a polynya (or area of open water) north of Ellesmere Island is remarkable. Researchers discovered that similar polynyas could have existed in 1988 and 2004 by using satellite data.
"North of Ellesmere Island, it's difficult to move or melt the ice because it's thick," Kent Moore, an Arctic researcher from the University of Toronto, stated in a statement. We have not seen polynyas in this region before.
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The Arctic is changing
The sea ice off Ellesmere Island's northern coast is more than 13 feet (4 m) thick, and averages 5 years old. This "last ice" in the Arctic is becoming vulnerable to the rapid warming occurring at the northern latitudes. A July 2021 study revealed that the Wandel Sea, which is the eastern region of the "last-ice" region, had lost half its overlying glaciers in summer 2020. A 2021 study found that the ice arches connecting the stable seaice to Greenland were forming later than expected and melting more quickly each year.
Researchers now believe that the last ice may melt each summer by the end century. This could spell doom for animals that depend on sea ice year round, like polar bears.
Another sign that the last ice is in trouble is the polynya. Polynyas can be cracks in sea ice that open up when there is wind. A strong storm erupted north of Ellesmere Island on May 2020. Satellite imagery revealed that a narrow crack or lead formed on May 14. The lead had become an elliptical polynya that was approximately 62 miles long (100 km) and 18.6 miles (30km) wide by May 15. The polynya was quickly closed on May 26.
Open waters
Researchers looked at satellite data that had previously recorded sea ice concentration. The researchers found evidence of a polynya opening in the area in May 1988. However, satellite imagery at that time was not clear enough to determine the size or shape of the opening. The second polynya occurred in May 2004. Researchers wrote that the winds at the 2004 event were stronger in 2004 than they were in 2020 or 1988, but that the 2004 opening was smaller than the 2020 one. They speculate that the ice has thinned over time, which could explain why weaker winds can open wider windows.
The statement said that "The formation of the polynya is really interesting" David Babb, a sea-ice researcher at the University of Manitoba, Canada, which was not part of the study. It's kind of like a crack within the shield of solid ice that normally covers that area. This is a great indicator of how the Arctic is changing.
Moore stated that polynyas could open up more often as the Arctic's last glacier melts. These open areas are oases of life in the short-term. Sunlight can reach the ocean waters, which allows for more algal photosynth, which attracts fishes and crustaceans. He said that these animals attract seabirds seals and polar bears. However, this surge of life is temporary.
Moore stated that "[O]n the long-term, as ice melts offshore and species such as walruses or seabirds are denied access to it," Moore explained. It eventually gets too warm for species to survive.
Original publication on Live Science
