Antarctic Ice is Behaving in a Way That Has Never Been Seen Before and Has Changed its Regime

Since the 2016 Antarctic ice minimum, the regime has changed and scientists are investigating what is causing it, and how it will behave in the future.

Antarctic sea ice
Antarctic sea ice has flown weaker or has disappeared in some sectors, opening the door to a regime change since the minimum of 2016.

In some sectors, the Antarctic sea ice, which contains the large icy mass that remains on the continent, has weakened, or in some cases disappeared in recent years. During the Antarctic summer, the Sun does not descend from the horizon, but the temperature behavior must be such that the coastal ice mass maintains an acceptable volume.

"When any part of the climate system is pressed, domino effects occur that are felt all over the world, not necessarily immediately, but over many years," explains Ella Gilbert - Polar Climatologist.

What has been observed in recent decades is that in some areas that support has completely disappeared, or is diminished in such a way that its containment will be much less effective. In fact, in Meteored we had already told you that the glaciers melt in the ocean faster than imagined, according to a study.

Ella Gilbert, polar climatologist at the British Antarctic Survey, explains to Live Science that Antarctic ice "is a vital part of our climate system." Although Antarctica seems a bit distant to us, not only the global climate system depends on its stability, but also the behavior of the seas. Until recently, Antarctic sea ice fluctuated between relatively stable summer lows and winter highs. But after a record low in 2016, things began to change.

Change of regime

After the 2016 low, two record lows followed, including the smallest low in history in February 2023, with only 1.91 million square kilometers. In March of last year, scientists expected the ice sheet to recover. But that was far from happening, since the Antarctic ice experienced six months of historic lows. This happened in a year where the surface temperatures of the sea globally climbed to unthinkal levels.

Antarctic ice extent
Extension of the Antarctic ice of 2023 and the current 2024 compared to the average values of the 1981 -2010 series - Data: National Snow and Ice Data Center

At the height of winter, in July 2023, Antarctica was missing a piece of ice larger than the size of Western Europe. "We all thought that the minimum was the worst thing that was going to happen; it was 2023, not 2070," Ariaan Purich, an Antarctic climate researcher at Monash University in Australia, told Live Science. "So when winter came, we didn't give credit."

Now in 2024, the extent of the Antarctic sea ice has reached another almost record low with only 1,985 million square kilometers on February 20. Researchers observe that there has been a profound "regime change" in Antarctica, and now they are trying to understand what will happen next. When summer becomes winter in Antarctica, sea ice expands from its minimum of about 3 million square kilometers to 18 million square kilometers, covering 4% of the Earth's surface.

The process behind the Antarctic ice

Polar climate specialists explain that most of this sea ice grows in winter, during the weeks of polar night, over open water areas on the floating ice shelf that surrounds the continent. The seawater holes, or polynias, inside the floating ice shelf freeze when splashed by snow, building the layer piece by piece.

The coastal ice mosaic has several purposes, explains Live Science. First of all, this sea ice pit keeps the sea water warm away from the increasingly precarious terrestrial ice of the continent, protecting its hanging glaciers. The surface of sea ice also reflects part of the solar energy into space in a process known as the albedo effect.

But there is another very relevant process, which if lost or attenuated has implications at a higher level. These floating platforms also play a key role in the Antarctic ecosystem, since they provide a habitat for creatures such as penguins and krill. Krill feeds on photosynthetic algae that grow around the platforms, and its poop retains carbon dioxide that then falls to the bottom of the ocean.