The extent of sea ice in summer Antarctica reached a record minimum on February 8 of this year. The previous low of February 24 last year was thus undercut several weeks before the end of the summer melting period. At that time, according to the Alfred Wegener Institute (AWI), a sea ice extent of 2.27 million square kilometers was recorded on the southern ocean around Antarctica. The melting period is expected to last into the second half of February.
According to the AWI, which worked together with researchers from the University of Bremen in its analysis, the sea ice cover in the Antarctic was at a historically low level throughout January. It was therefore the eighth year in a row that the mean sea ice cover in the Southern Ocean in January was below the long-term trend.
"The rapid decrease in sea ice over the past six years is very astonishing because the ice cover had hardly changed in the previous 35 years," explained AWI sea ice physicist Christian Haas. "It is unclear whether this is the beginning of a rapid end to summer sea ice in Antarctica, or whether it is just a new phase of reduced but still stable summer sea ice coverage," he added.
It's summer in the southern hemisphere right now. Around the Antarctic, the sea ice then melts completely in some regions. In winter, new sea ice forms quickly due to the extreme cold, until it reaches a maximum extent of around 18 to 20 million square kilometers.
One possible reason for the strong current melt is unusually warm air temperatures in parts of Antarctica. However, complex interactions between air pressure, wind circulation and ocean currents also played a role. This also affects the ice retreat.
Franziska Saalmann from the environmental organization Greenpeace explains in this context: "The new record low shows us that the climate crisis is escalating - Antarctica seems far away, but the effects affect us all." It is a scandal that new fossil projects are still being planned worldwide.
Comparable seasonal changes in sea ice cover also occur in the seas around the Arctic. According to the AWI, however, the natural seasonal fluctuations are much more pronounced in the Antarctic. Changes in sea ice cover do not affect global sea level because the ice is already floating in the water. This is different with mainland ice. When that melts, additional water enters the oceans.
Sources: Greenpeace, AWI, DPA, AFP