A huge hole has been detected on the Antarctic sea ice deck. The scientific name of this opening is a polynia (an open space of water surrounded by ice). It is the largest that has been detected since the 1970s in the Weddell Sea. With about eighty thousand square kilometers, it has the approximate extension of Panama.
But its enormous size is not the strangest of this huge hole in the ice. Although pollinias are common in coastal ice regions, at the edge of ice sheets; this particular has occurred in the heart of the same, in an area called ice pack, where ice sheets extend beyond the continent.
Scientists from the SOCCOM project (Southern Ocean Carbon and Climate Observations and Modeling) were surprised to discover that a float in the Weddell Sea had emerged inside the polynia.
Ocean measurements are being analyzed as part of a study on the Weddell Sea Polynes. With these new observations arises the possibility that the secrets of this mysterious and enormous hole can, at last, be revealed.
How do pollinias form?
In recent studies, SOCCOM affiliated researchers have used climate models to explore why these pollinias form and how they affect oceanic and atmospheric patterns.
However, the difficulty of setting up Antarctic expeditions in winter means that few measurements of these rare events have been made.
Polynes, therefore, are frequent in coastal areas of ice sheets , but how is it possible for a frozen continental zone to sink to give rise to this huge ‘gap’ in the ice?
The SOCCOM project has a range of robotic profile floats that can collect ocean measurements throughout the year, including under sea ice. Scientists point out that the huge polynia has formed due to Weddell’s deep sea waters, warmer and saltier than surface waters; therefore, convection marine currents would have resulted in the destruction of the ice.
As the ice melts, more and more sea water is exposed to the cold atmosphere, where it cools and sinks. In doing so, it gives way to higher temperature waters, and the process repeats itself. All this hinders the formation of new ice sheets.
It is too early to say that climate change is responsible for this phenomenon, but it is necessary to study it in depth given its extraordinary character.