The Earth’s poles have been exhibiting some surprising climatic influences. The poles usually go through temperature changes causing them to lose ice deposits during the summers and recover during the cold seasons. During the last years though, the Northern Arctic Sea has expanded, taking bites out of the thick polar ice sheet. But on the other side of the world, the Southern Antarctic sea-ice recorded the highest surface ever on September 13th.
Satellites measure the ocean surface that freezes during each winter. Sea-ice is the surface of the ocean with more than 15 percent ice. The National Snow and Ice Data Center (NSIDC) announced that the sea-ice surface surrounding the South Pole reached 7.6 million square miles. The region will have another couple of weeks with freezing temperatures, so the surface will increase further, according to scientists. In fact, this would be the third consecutive year when the Antarctic sea-ice surface expands. Only 88.000 square miles are needed to exceed last year’s surface.
Stronger than usual freezing winds helped the sea-ice extend its surface, scientists claim. The winds manage to keep the newly formed ice stay together and maintain low temperatures. Moreover, the sea water keeps losing salt from its composition due to previous ice sheet melting, making the freezing process more effective.
“In the short term, it seems like there hasn’t been much ice loss in the past couple of years, but I think it’s still very much within the long-term trend of declining sea ice,” said Axel Schweiger from the Polar Science Center, University of Washington. “One shouldn’t necessarily expect every year to be a record low.”
In the meantime, the Northern Arctic ice cap retreated to a dangerously low surface, similar to the 1.97 million square miles from 2013. Sea-ice is important because it protects the thick ice surrounding the poles called multilayer ice. This ice has a higher resistance to melting. The Siberian Laptev Sea advanced drastically, getting closer to the North Pole than ever before.
But while the sea-ice surrounding Antarctica expanded, the formation suffered changes. Some ice-seas are expanding, while others are retreating, changing the shape of the continent’s surface. In the meantime, the ice-sheet keeps retreating, although at lower levels than its Northern counterpart.
The changes suffered by both the Northern and the Southern polar ice sheets are influenced by climate changes, scientists warn. However, the effects are highly noticeable in the Arctic Sea, while not so much in Antarctica.