A massive hole appeared in the middle of Antarctica's sea ice in 2017, perplexing scientists because the phenomenon was known to occur in the 70s.
The hole, called a polynya, was spotted through satellite images of Antarctica. It appeared on the Lazarev Sea and was said to span hundreds of thousands square kilometers across.
Now, a team of researchers believes that they know what caused the mystery hole.
Antarctica Has A Hole
Around mid-September 2017, scientists spotted a 9,500-square-kilometer hole at the center of an ice pack over the Lazarev Sea. They named it Maud Rise Polynya because it was located on the ocean plateau Maud Rise. By October, the mysterious hole has grown to 800,000 square kilometers.
Scientists were surprised to see the polynya because the sea ice in Antarctica is at its thickest during the winter. The phenomenon was also known to occur in the 70s back when satellite observations of the frozen continent were just becoming more common.
Eventually, Maud Rise Polynya disappeared when the ice started to retreat during the summer months.
Cyclone Creates Polynya
A study led by research scientists Diana Francis from NYU Abu Dhabi investigated the four decade-year-old mystery of mid-sea polynya just like the one that appeared on the Lazarev Sea in 2017. They believe that a cyclone might have opened the ice.
"Once opened, the Polynya works like a window through the sea-ice, transferring huge amounts of energy during winter between the ocean and the atmosphere," explained Francis. "Because of their large size, mid-sea Polynyas are capable of impacting the climate regionally and globally as they modify the oceanic circulation."
The research scientist added that it is important to understand the phenomenon, the factors that triggered it, and how it affects the climate.
Francis also warned that similar-sized polynyas are likely to appear more often as the global temperature continues to rise. The are will be exposed to more intense cyclones caused by the changing climate.
" Previous studies have shown that under a warmer climate, polar cyclone activity will intensify and extratropical cyclones track will move toward Antarctica which could decrease the sea-ice extent and make Polynya areas, closer to the cyclones formation zone," she stated.
They published their findings in the American Geophysical Union's Journal of Geophysical Research: Atmospheres.