Antarctica gained about 695 billion tons of ice between 2021 and 2023, the largest increase recorded by the Gravity Recovery and Climate Experiment, GRACE, satellite missions. Researchers traced the increase to heavy snowfall over East Antarctica, driven by warmer ocean conditions thousands of miles away.
The finding showed how distant parts of the climate system interact, while also explaining why a few years of growth cannot label Antarctica as recovering.
The process began in the tropical warm pool, where the western Pacific meets the eastern Indian Ocean. Sustained warming there changed atmospheric circulation through a Rossby wave train, a series of large atmospheric waves that carried the disturbance toward Antarctica.
This helped create unusually low pressure south of Australia, and high pressure along the East Antarctic coast.
Together, these pressure changes redirected moist air from the Indian Ocean toward the continent. More atmospheric rivers, narrow corridors carrying large amounts of water vapor, reached East Antarctica.
In the cold Antarctic environment, that moisture fell as snow, producing substantial accumulation across Queen Mary Land and Wilkes Land.
Global warming elsewhere can therefore increase Antarctic snowfall by changing where moisture travels.
However, researchers found that the general increase in atmospheric moisture associated with human-caused warming explained only about 9% of the snowfall increase.
The specific circulation pattern connected to tropical ocean warming was the main driver. This distinction matters because simply saying that warmer air holds more moisture leaves out how the extra snowfall reached Antarctica. The study connected the tropical conditions to the Antarctic response using observations and computer experiments.
Measuring an entire continent requires more than checking snowfall at a few research stations. The GRACE satellite missions detect changes in Earth’s gravity caused by shifts in mass.
As Antarctica gains or loses ice, its gravitational pull changes slightly, allowing scientists to estimate changes across broad regions. Researchers combined these satellite measurements with snow accumulation records preserved in ice cores.
They also used atmospheric models and water-vapor tracking simulations to investigate where the moisture originated and how it moved. These different methods helped connect the measured ice gain to the weather patterns responsible for it.
The temporary increase does not overturn long-term expectations of Antarctic ice loss and rising sea levels. Over the past two decades, Antarctica has lost an estimated average of 140.5 billion tons annually. West Antarctica continues losing mass, while warm ocean water melts some East Antarctic ice shelves from below and contributes to faster glacier flow.
Extra snowfall can temporarily offset losses without removing the processes causing them. Scientists can use this finding to improve predictions of changes over several years, however, it provides no basis for declaring a long term solution. Furthermore, they said that focusing only on the record gain would hide the longer history, like judging an entire season from a brief cold spell.
The study demonstrated why climate records need both a wide geographic view and enough years to separate temporary fluctuations from lasting change.
