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Sea ice and clouds blanket the Weddell Sea around Antarctica in this satellite image from September 25, 2017. A SOCCOM float surfaced within the 60,000 km2 polynya (center) at the location marked in yellow. Image credit: MODIS-Aqua via NASA Worldview; sea ice contours from AMSR2 ASI via University of Bremen.

Science

Scientists affiliated with the Southern Ocean Carbon and Climate Observations and Modeling project (SOCCOM) have discovered a mysterious hole the size of Lake Superior opening up in Antarctica. Known as a polynya, this mysterious 80,000 square-kilometer opening is the largest observed in the Weddell Sea since the 1970s, but researchers caution that it would be “premature” to blame it on climate change.

Kent Moore, professor of atmospheric physics at U of T Mississauga, told Vice that the hole will have a large impact on the oceans. Moore has been working with SOCCOM at Princeton University to monitor the area with satellite technology. They're also using robotic floats that are capable of operating under sea ice.

In recent studies, SOCCOM-affiliated researchers have used climate models to explore why these polynyas form and how they affect ocean and atmospheric circulation patterns. However, the difficulty of mounting Antarctic expeditions in winter means that few actual measurements have been made of these rare events.

With the array of robotic profiling floats deployed as part of the SOCCOM project, an impromptu Antarctic expedition may not be necessary. Floats can collect ocean measurements year-round, even underneath sea ice. Last month, SOCCOM scientists were astonished to discover that a float in the Weddell Sea had surfaced inside the polynya, making contact with satellites in the dead of winter. Its new ocean measurements, transmitted when it surfaced, are being analyzed as part of a study in preparation on Weddell Sea polynyas. With these new observations comes the possibility that the polynya’s secrets may finally be revealed.

Researchers say that with new ocean measurements, the space-based images and climate models, they're hoping to finally unravel the polynyas’ secrets and their impacts on the climate.

The holes form in coastal regions of Antarctica, but what's unusual here is that this polynya is “deep in the ice pack,” Moore says.

Scientists believe the polynya is formed because of the deep water in the Southern Ocean being warmer and saltier than the surface water. Ocean convection occurs in the polynya by bringing warmer water to the surface, which then melts the sea ice and prevents new ice from forming.

SOCCOM is an NSF-sponsored program.

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