“We’re still trying to figure out what’s going on.”
By Kate Lunau
A hole as large as Lake Superior or the state of Maine has opened up in Antarctica, and scientists aren’t sure why it’s there.
The gigantic, mysterious hole “is quite remarkable,” atmospheric physicist Kent Moore, a professor at the University of Toronto’s Mississauga campus, told me over the phone. “It looks like you just punched a hole in the ice.”
Areas of open water surrounded by sea ice, such as this one, are known as polynias. They form in coastal regions of Antarctica, Moore told me. What’s strange here, though, is that this polynia is “deep in the ice pack,” he said, and must have formed through other processes that aren’t understood.
“This is hundreds of kilometres from the ice edge. If we didn’t have a satellite, we wouldn’t know it was there.” (It measured 80,000 k㎡ at its peak.)
A polynia was observed in the same location, in Antarctica’s Weddell Sea, in the 1970s, according to Moore, who’s been working with the Southern Ocean Carbon and Climate Observations and Modelling (SOCCOM) group, based at Princeton University, to analyze what’s going on. Back then, scientists’ observation tools weren’t nearly as good, so that hole remained largely unstudied. Then it went away for four decades, until last year, when it reopened for a few weeks. Now it’s back again.
“This is now the second year in a row it’s opened after 40 years of not being there,” Moore said. (It opened around September 9.) “We’re still trying to figure out what’s going on.”
It’s tempting to blame this strange hole on climate change, which is reshaping so much of the world, including Antarctica. But Moore said that’s “premature.” Scientists can say with certainty, though, that the polynia will have a wider impact on the oceans.
“Once the sea ice melts back, you have this huge temperature contrast between the ocean and the atmosphere,” Moore explained. “It can start driving convection.” Denser, colder water sinks to the bottom of the ocean, while warmer water comes to the surface, “which can keep the polynia open once it starts,” he said.
Using observations from satellites and deep sea robots, Moore and his collaborators are working on as-yet-unpublished research that aims to answer some of these questions. “Compared to 40 years ago, the amount of data we have is amazing,” he said.
Antarctica is undergoing massive changes right now, and figuring out why a gaping hole could suddenly open up will be key to understanding larger systems at play.
This article (A Giant, Mysterious Hole Has Opened Up in Antarctica) was originally published on Motherboard and syndicated by The Event Chronicle.
Continues from The Independent…
A giant hole has opened up in Antarctica as scientists look to find out what is to blame
‘It looks like you just punched a hole in the ice’
A hole larger than the Netherlands has opened up in Antarctica, and scientists are working to deepen their understanding of how it formed.
The hole in the ice is “quite remarkable,” University of Toronto Mississauga professor Kent Moore told Motherboard.
“It looks like you just punched a hole in the ice,” he said.
Areas of open water surrounded by ice are known by the Russian word “polynya”. They occur regularly in the Antarctic and Arctic, but typically in coastal regions.
This polynya was first observed by satellites in the 1970’s in the Weddell Sea, east of the Antarctic Peninsula.
The hole reopened again this year, marking “the second year in a row it’s opened up after 40 years of not being there,” Mr Moore said.
Back then, scientist had a limited ability to study the phenomenon.
“At that time, the scientific community had just launched the first satellites that provided images of the sea-ice cover from space,” Torge Martin, a meteorologist and climate modeller, told Phys.org.
“On-site measurements in the Southern Ocean still require enormous efforts, so they are quite limited.”
But the Weddell Polynya is reasonably well understood.
Professor Mojib Latif told the site: The Southern Ocean is strongly stratified. A very cold but relatively fresh water layer covers a much warmer and saltier water mass, thus acting as an insulating layer.”
Certain conditions cause the warm water on the lower layers to reach the surface and melt the ice.
“This is like opening a pressure relief valve – the ocean then releases a surplus of heat to the atmosphere for several consecutive winters until the heat reservoir is exhausted,” Mr Latif added.
Now, scientists are working to understand how often the polynya occurs and whether it is influenced by climate change.
However, Mr Moore told Broadly blaming climate change was “premature,” while other climate scientists said they were keen to differentiate between manmade global warming and natural changes to the climate system.
Scientists have said the polynya will have a wider impact on the oceans as the temperature contrast between the ocean and atmosphere drives convection.
This article (A giant hole has opened up in Antarctica as scientists look to find out what is to blame) was originally published on The Independent and syndicated by The Event Chronicle.