Southern Ocean Waters Are Getting Warmer and Saltier, Study Warns

Researchers have discovered another unexpected shift in the Southern Ocean.

Surface water salinity is rising, and sea ice is in steep decline. The latest discovery came as Antarctica is deeply suffering from the consequences of climate change and global warming.

Since 2015, Antarctica has lost sea ice equal to the size of Greenland.

This proves that the Southern Ocean is also getting saltier, and this unexpected change is worsening the crisis.

For decades, the ocean's surface was less salty, helping sea ice grow. Now, scientists say that situation has sharply reversed.

Using European satellite data, research led by the University of Southampton has discovered a sudden rise in surface salinity south of 50° latitude.

This is parallel with a dramatic loss of sea ice around Antarctica and the re-emergence of the Maud Rise polynya in the Weddell Sea.

The findings have been published on 30 June in the Proceedings of the National Academy of Sciences.

Dr. Alessandro Silvano from the University of Southampton who led the research said, "Saltier surface water allows deep ocean heat to rise more easily, melting sea ice from below. It's a dangerous feedback loop: Less ice leads to more heat, which leads to even less ice.

"The return of the Maud Rise polynya signals just how unusual the current conditions are. If this salty, low-ice state continues, it could permanently reshape the Southern Ocean—and with it, the planet. The effects are already global: stronger storms, warmer oceans, and shrinking habitats for penguins and other iconic Antarctic wildlife."