Thursday, 14 December, 2017

Giant hole the size of ME reopens in Antarctica's Weddell Sea

Mysterious giant hole opens up in Antarctica Mysterious giant hole opens up in Antarctica
Theresa Hayes | 12 October, 2017, 14:08

Scientists have discovered a hole as big as the state of ME or Lake Superior in the frozen ice of Antarctica's Weddell Sea, according to a report in the National Geographic. Scientists measured that the huge sea ice hole or polynya is nearly 80,000 square kilometers at its peak- a little bigger than New Brunswick and a bit smaller than the island of Newfoundland.

"At that time, the scientific community had just launched the first satellites that provided images of the sea-ice cover from space", said Torge Martin, a meteorologist and climate modeler, as quoted by Phys.org.

A "polynya" is a large ice-free area that develops in an otherwise frozen sea; the features are commonly seen in both the Arctic and Antarctic sea ice. With a bit of push from nature (ocean currents), the warmer water rises upwards melting the blankets of the surface ice.

'It looks like you just punched a hole in the ice, ' atmospheric physicist Kent Moore, a professor at the University of Toronto Mississauga, told Motherboard. Did the Weddell polynya occur before 1970, and we are looking at a periodic process that shows itself about every 40 years?

At its peak, the Weddell Polynya measured a staggering 80,000 square kilometers (roughly 31,000 square miles). The polynya's occurrence confirms what scientists had previously calculated, and they want to know what made the hole reopen for two years in a row after four decades of not being there.

Scientists believe the polynya is formed because of the deep water in the Southern Ocean being warmer and saltier than the surface water.

It's not clear at this point if the ice hole is influenced in any way by climate change. Then it reheats in deeper areas, allowing the cycle to continue.

Simulated temperature development in the area of the polynya is illustrated above.

The Weddell Sea polynya went away for four decades, until it reopened a year ago for a few weeks.

The latest hole is way bigger than the last discovered and was spotted by scientists from the University of Toronto and the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) group.

'Global warming is not a linear process and happens on top of internal variability inherent to the climate system, ' Latif says. A more thorough and prolonged research would reveal the real reason behind the huge hole.

"We don't really understand the long-term impacts this polynya will have", he says.