A tropical warming event helped drive record snowfall and a temporary 695-billion-ton ice gain in East Antarctica without reversing long-term Antarctic ice loss.
Between 2021 and 2023, the Antarctic Ice Sheet gained about 695 billion tons of mass, the largest increase recorded by the GRACE satellites. New research traces much of that unusual gain to sustained warming thousands of miles away in the tropical western Pacific and eastern Indian Ocean, which altered atmospheric circulation and sent more moisture toward East Antarctica.
The finding stands out against Antarctica’s longer trend. Over the past two decades, the ice sheet has lost mass at an average rate of about 140.5 billion tons per year, making its future contribution to global sea-level rise a major source of uncertainty. The temporary gain did not reverse that decline, but it revealed how conditions in the tropics can influence Antarctic snowfall over several years.
The study was published in Nature.
Researchers led by the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) combined gravity-satellite observations, ice-core snow-accumulation records, water-vapor tracking, and atmospheric circulation simulations to investigate what caused the 2021–23 event.
Tropical warming redirected moisture south
During those years, the tropical warm pool where the western Pacific meets the eastern Indian Ocean remained unusually warm. According to the study, that sustained warming triggered a Rossby wave train that propagated toward high southern latitudes and reshaped atmospheric circulation over East Antarctica.
Eddy-mean flow feedbacks strengthened and maintained the pattern, producing a north–south dipole with low-pressure anomalies south of Australia and high-pressure anomalies along the East Antarctic coast. The resulting circulation redirected moisture from the midlatitude Indian Ocean toward Antarctica and increased the number of atmospheric rivers reaching the continent.
Water-vapor tracking simulations showed that this influx of moist air produced persistent heavy snowfall across the Queen Mary Land–Wilkes Land region, adding mass to the ice sheet.
Atmospheric circulation experiments identified the tropical warm pool as the direct driver of the circulation and snowfall response. By comparison, the increase in regional snowfall attributed to anthropogenic forcing amounted to only 9% of the observed snowfall anomaly, indicating that atmospheric moistening associated with global warming was not the primary cause of the event.
The researchers also found that similar periods of sustained tropical warm-pool warming occur roughly once a decade. This recurring connection suggests that conditions in the tropical ocean can influence multiyear changes in snowfall and ice mass across East Antarctica.
The ice gain does not reverse losses
Despite the temporary increase, Antarctica remains on a long-term trajectory of ice-sheet mass loss. The West Antarctic Ice Sheet continues to lose ice, while some outlet glaciers in East Antarctica face basal melting of their ice shelves and faster ice flow driven by warm ocean waters.
The study identifies the north–south dipole circulation over East Antarctica as a key link between tropical warming and changes in Antarctic ice mass, providing a mechanism for how distant ocean conditions can alter snowfall across the continent.
“We found a previously underrecognized ‘tropical warm pool–East Antarctic Ice Sheet’ teleconnection pathway,” said Yunhe Wang from IOCAS, first author of the study. “Our research provides a theoretical basis for understanding Antarctic ice-sheet mass changes and conducting future research on the East Antarctic climate.”
Reference: “Multiyear tropical warm pool warming drives slowdown in Antarctic mass loss” by Yunhe Wang, Qinghua Ding, Xiaofeng Li, Thomas J. Ballinger, Yoshihiro Nakayama, Dániel Topál and Eric J. Steig, 19 August 2026, Nature.
DOI: 10.1038/s41586-026-10912-x
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