Antarctica gained 695 billion tons of ice after tropical ocean warming altered snowfall patterns
Antarctica has been losing ice for decades — roughly 140 billion tons a year, on average. So when satellites recorded a net gain of 695 billion tons across the continent between 2021 and 2023, researchers took notice. It was the largest Antarctic mass increase ever captured by the GRACE satellite missions, arriving at a moment when few scientists were looking for good news from the ice sheet.
What caused it wasn’t obvious — and the answer turned out to be thousands of miles away.
A record that defied expectations
Between 2021 and 2023, the Antarctic Ice Sheet gained approximately 695 billion tons of mass. Set against the continent’s long-term average loss of roughly 140.5 billion tons per year over the past two decades, that number becomes almost paradoxical. This wasn’t a modest fluctuation. It was the largest Antarctic mass gain ever recorded by the GRACE satellite missions — instruments designed to detect subtle changes in Earth’s gravitational field caused by shifting ice and water.
Steig. Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss. Nature, 2026; 656 (8129): 897 DOI: 10.1038/s41586-026-10912-x
The gain was concentrated in East Antarctica, particularly in the Queen Mary Land–Wilkes Land region. Researchers from the Institute of Oceanology of the Chinese Academy of Sciences drew on gravity satellite data, snow accumulation records from ice cores, and atmospheric circulation simulations to trace the moisture backward and find its source.
A signal born in the tropics
The trail led somewhere unexpected. The team traced the anomaly to the tropical warm pool — the stretch of ocean where the tropical western Pacific meets the eastern Indian Ocean, home to some of the warmest surface waters on the planet. Between 2021 and 2023, that region experienced sustained, above-normal warming that set off a chain of atmospheric changes eventually reaching Antarctica.
The mechanism was a Rossby wave train. When unusual ocean heat disturbs the atmosphere, it propagates that energy outward in a rippling wave pattern — like a stone dropped in still water. These waves can travel thousands of miles, carrying the atmospheric “memory” of a tropical disturbance all the way into polar regions. A process called eddy mean flow feedback then made the effect more durable, amplifying and extending the resulting circulation pattern and turning what might have been a brief atmospheric hiccup into a persistent reorganization of weather systems around Antarctica.
How the atmosphere delivered the moisture
As the Rossby wave reached high southern latitudes, it established a striking pressure pattern: unusual low pressure south of Australia paired with unusual high pressure along the East Antarctic coast. Scientists call this a north-south dipole.
That configuration mattered enormously for moisture movement. Atmospheric rivers — narrow, high-altitude corridors carrying enormous quantities of water vapor — were redirected away from their usual midlatitude paths and funneled toward East Antarctica instead. Water vapor tracking simulations confirmed this pathway. Moist air from the midlatitude Indian Ocean was channeled onto the continent, where colder temperatures converted it into snow — enough to add hundreds of billions of tons to the ice sheet over two years.
Not a human fingerprint — but not random either
One of the study’s more striking findings concerns what didn’t cause the ice gain. Researchers tested how much of the snowfall increase could be attributed to anthropogenic climate forcing — the background warming and moistening of the atmosphere driven by human emissions. The answer: roughly 9%. A real contribution, but a minor one.
The dominant driver was natural variability in tropical ocean temperatures. That distinction matters. This event wasn’t primarily a product of climate change — but it also wasn’t purely random noise. The tropical warm pool experiences sustained warming episodes approximately once per decade, according to the researchers, which makes this type of Antarctic ice gain a recurring, if infrequent, phenomenon tied to recognizable tropical ocean cycles.
The team describes the tropical warm pool as a remote “regulator” of East Antarctic snowfall and ice mass on multi-year timescales — a framing that could reshape how scientists think about ice sheet variability going forward.
A temporary pause in a long decline
None of this alters the broader trajectory. The researchers are direct: the 2021–2023 gain was temporary. It doesn’t reverse Antarctica’s long-term ice loss or offset the decades of decline that came before it. West Antarctica continues to shed mass, and outlet glaciers in parts of East Antarctica remain vulnerable to warm ocean water eroding ice shelves from below.
What the study does clarify is the system’s complexity. By identifying what the authors call a previously unrecognized “tropical warm pool–East Antarctic Ice Sheet” teleconnection pathway, the research points toward a missing variable in climate models — one that could affect projections of future sea-level rise. A patch of warm ocean halfway around the world quietly reshaped the ice sheet for two years, and researchers only understood why after the fact.
It’s a reminder that Earth’s climate system is deeply interconnected in ways that still surprise us — and that our models, however sophisticated, are still catching up.
You can discovery more about this study here: Yunhe Wang, Qinghua Ding, Xiaofeng Li, Thomas J. Ballinger, Yoshihiro Nakayama, Dániel Topál, Eric J. Steig. Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss. Nature, 2026; 656 (8129): 897 DOI: 10.1038/s41586-026-10912-x
Daniel García is an Editor-in-Chief with strong expertise in structural work and engineering principles. He combines this technical foundation with deep knowledge of energy, spatial design, and emerging technologies, bringing a forward-thinking and analytical approach to editorial leadership.
