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Tropical Warm Pool Linked to East Antarctic Snowfall Surge
Confirmed
In Short: Researchers have identified a previously underrecognized connection between the tropical warm pool and East Antarctic snowfall.
Researchers have identified a previously underrecognized connection between the tropical warm pool and East Antarctic snowfall.
The study, published in Scitechdaily, reveals that sustained warming in the tropical western Pacific and eastern Indian Ocean altered atmospheric circulation, resulting in record snowfall and a temporary 695-billion-ton ice gain in East Antarctica between 2021 and 2023.
According to Yunhe Wang from IOCAS, the first author of the study, 'We found a previously underrecognized ‘tropical warm pool–East Antarctic Ice Sheet’ teleconnection pathway.
The tropical warm pool, where the western Pacific meets the eastern Indian Ocean, remained unusually warm during this period, altering atmospheric circulation patterns.
These changes produced a north–south dipole with low-pressure anomalies south of Australia and high-pressure anomalies along the East Antarctic coast.
This pattern helped create unusually low pressure south of Australia and high pressure along the East Antarctic coast, leading to more atmospheric rivers reaching East Antarctica.
In the cold Antarctic environment, this moisture fell as snow, producing substantial accumulation across Queen Mary Land and Wilkes Land.
The study also 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 of the snowfall surge.
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.
This distinction is crucial because it clarifies how the extra snowfall reached Antarctica, rather than attributing it solely to warmer air holding more moisture.
What this adds
The research highlights the complex interplay between tropical ocean conditions and Antarctic snowfall, suggesting that similar warming events may recur roughly once a decade.
What's confirmed
- During those years, the tropical warm pool where the western Pacific meets the eastern Indian Ocean remained unusually warm.
What's still developing
- The temporary gain did not reverse that decline, but it revealed how conditions in the tropics can influence Antarctic snowfall over several years.
- Between 2021 and 2023, the Antarctic Ice Sheet gained about 695 billion tons of mass, the largest increase recorded by the GRACE satellites.
- It turns out this subsurface region measures about 200 to 400 degrees Celsius warmer than the rest of the mantle.
- That warm spot may contain information about heating inside the planet and how Mars has changed over its lifetime.
- Sustained warming there changed atmospheric circulation through a Rossby wave train, a series of large atmospheric waves that carried the disturbance toward Antarctica.
- 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.