An international team of scientists has found that summer sea ice in the Weddell Sea in Antarctica is shrinking sharply,media New Atlas reported. Since 2015, the ice cover has been reduced by 1 million square kilometers, potentially creating problems for the survival of local marine life. Antarctica is a famous frozen continent, covered with glaciers, and in some places glaciers are miles deep. However, sea ice flows, breaks, shrinks and grows with the seasons in a very complex way, not just when it comes to snow or temperature changes.
Weddell sea is an example. Researchers from the British Antarctic Survey (BAS), the National Polar and Marine Research Centre in India, Nanjing University and Victoria University in Wellington, New Zealand, have been studying satellite records of sea ice extents and weather analysis in the late 1970s to try to understand why summer sea ice has been reduced by a third in five years.
They found that the Weidel Sea experienced several severe summer storms in 2016 and 2017. When such storms occur in the North and South Poles, they destroy the ice pack and push the resulting ice floes, causing them to melt faster. However, the team also found an open surface, or a multi-angled area — something that hasn’t happened in nearly 50 years.
“Antarctic sea ice continues to surprise us,” says Professor John Turner, a climate scientist at the British Antarctic Survey. “Compared to the Arctic, sea ice around Antarctica has been increasing since the 1970s, but has since quickly declined to record lows, with the Greatest Decline in the Weddell Sea. During the summer, sea ice in the area is now reduced by a third, which will affect the region’s ocean circulation and the marine wildlife on which it depends. “
Antarctica’s winter sea ice is twice the size of summer, and by late September it covered 18 million square kilometers (6.9 million square miles), according to the team. With the exception of Weddell Overseas, most of which melt in the summer, most are still frozen on top. That changed in December 2016, when strong storms attracted warm air and contributed to the melting. The sea then absorbs solar radiation, warming it and prolonging the effect, including maintaining the multi-cloud formation of strong winds.
Worryingly, the loss of this sea ice will have a significant impact on the wedle Sea ecosystem. Many plants and animals are adapted to live in sea ice, and the loss of sea ice can affect the entire food chain, from plankton and krill to seals, penguins and whales. It may also be a long-term question, as it remains to be seen whether such losses will reverse as they have in the past, or whether they will begin a long-term recession.
“The dramatic decline in sea ice observed in the Weddell Sea is likely to have a significant impact on how the entire marine ecosystem works,” said Professor Eugene Murphy, an ecologist from the British Antarctic Survey. “Understanding these broader consequences is critical, especially if the ice extent continues to decline. “
The findings were published in Geophysical Research Letters.