Study reveals Antarctic ice sheet experienced temporary mass gain

A recent international study shows that the Antarctic ice sheet experienced a mass gain of 695 billion metric tons during the period from 2021 to 2023.

This had the effect of slowing the long-term rate of ice loss on the continent amid the phenomenon of climate warming.

Researchers from China, the United States, Hungary and Japan found that the ice mass gain was the largest ever recorded in nearly two decades of satellite observation.

They believe that an atmospheric phenomenon occurring thousands of kilometres away was the cause of the gain, whereby warm tropical oceans triggered heavy snowfall on the world’s southernmost continent and offset ice loss from melting.

The Antarctic ice sheet is one of the main sources of uncertainty for global sea level rise. During the period from 2003 to 2024, the continent lost an average of around 140.5 billion metric tons of ice per year.

The lead author of the study, Wang Yunhe, an associate researcher at the Institute of Oceanology under the Chinese Academy of Sciences (CAS), said that the unusual ice mass gain was driven by warming in the tropical western Pacific Warm Pool, one of the warmest marine regions in the world and one of the largest sources of heat release to the atmosphere.

From 2021 to 2023, sea temperatures in that region experienced unusual and sustained warming, which ultimately altered atmospheric circulation patterns.

“Water vapour from the Indian Ocean at mid-latitudes was carried towards East Antarctica, bringing heavy snowfall to the region and causing the ice sheet mass to increase,” Wang said.

However, the research published in the journal Nature noted that similar warming events occur roughly once a decade, indicating that the ice mass gain is temporary and cannot reverse the long-term trend of ice loss.

Wang added that West Antarctica continues to lose ice, while ocean warming threatens a number of glaciers flowing into the sea in East Antarctica by melting the ice sheet from below and accelerating ice flow.

In a companion commentary also published in the journal Nature, Jonathan Wille, a researcher at the French National Centre for Scientific Research, wrote that researchers must take tropical climate variability into account in order to understand the future of Antarctica and the planet as a whole.