A huge hole has opened up in Antarctic ice pack, reason unknown


According to scientists, the formation of huge holes in the ice layer on the sea surface can lead to significant climate changes as a result of the circulation of sea water, and further analysis of the data will help to more accurately assess the possible consequences of these processes for the terrestrial climate. Some American scientists think that this polynya will never re-appear, as melting ice and more precipitation in the air separates the surface ice sheet from deeper layers of water. According to NASA Earth Observatory, scientists had observed a similar polynya and that too in the same area in 1974.

Scientists first spotted it via satellite in the early '70s, when it opened up for three consecutive winters. This is the second year that a polynya formed, though last year's hole was not as big.

After closing back up, and remaining that way for roughly 40 years, it has re-opened.

It's been open for four months so far in 2017 "and my guess is it will stay open for the rest of winter", Moore added. "Its recurrence supports our hypothesis... that the Weddell Polynya was not a one-time event but possibly occurred regularly in the past". In an otherwise thick layer of sea ice, still frozen from the Antarctic winter, the hole is an aberration. "It's a couple of hundred kilometres away from the coast", Moore said.

What is not fully known, however, is how climate change might affect this process.

Researchers, including a group at the GEOMAR Helmholtz Center for Ocean Research Kiel, have been closely monitoring the polynya since it first reappeared in the satellite data.

An elephant seal lounges in the South Shetland Islands, Antarctica, on March 6, 2016. But in 1976, the opening closed up seemingly for good.

The cooling of the warmer ocean water when it reaches the surface may also have a broader impact on the ocean's temperature, but Moore says outside of local weather effects, scientists aren't sure what this polynya will mean for Antarctica's oceans and climate, and whether it is related to climate change.

Scientists are now collecting as much data as they can.

And they plan to study the region for years to come. & Gnanadesikan, A. Global atmospheric teleconnections and multidecadal climate oscillations driven by Southern Ocean convection.