A Monumental Storm Dropped 16 Billion Tons of Snow on Greenland, Slowing Soften of Ice Sheet

Greenland’s ice sheet is the second-largest ice cap on Earth, and due to the planet’s rising temperatures, it’s melting. Human-induced local weather change is intensifying atmospheric rivers, however new analysis suggests their affect on Greenland’s ice sheet is extra advanced than as soon as thought.

A analysis pair has investigated the latest affect of an intense atmospheric river—a channel of water vapor that brings moisture and warmth from hotter oceans to colder areas—on Greenland’s ice sheet. Unexpectedly, they discovered that this phenomenon deposited 16 billion tons of snow on Greenland, sufficient to briefly gradual its ice soften. As detailed in a study printed March 3 within the journal Geophysical Analysis Letters, atmospheric rivers might need a extra constructive affect than researchers had theorized.

“I used to be stunned by simply how a lot snow was dumped on the ice sheet over such a brief interval,” Alun Hubbard, a glaciologist on the Arctic College of Tromsø and examine co-author, mentioned in an American Geophysical Union (AGU) statement. “I believed it’d be a minute quantity, however it’s a gobsmacking contribution to Greenland’s annual ice mass.”

Global warming is melting Greenland’s ice sheets at unprecedented charges. In 2023, the ice sheet lost 80 gigatons of water—that’s roughly 660,430 gallons (2.5 million liters) of water per second. In 2024, it shrank for the 28th year in a row. If the complete ice sheet had been to soften, the ocean degree would rise by over 23 toes (7 meters). Local weather scientists predict that local weather change can even intensify atmospheric rivers, making them stronger and extra frequent, which might speed up ice loss in Greenland.

Nonetheless, an atmospheric river that occurred in March 2022 challenges this notion. On the time, lead writer Hannah Bailey, a geochemist on the College of Oulu, was in Svalbard. Because the atmospheric river pummeled the small Norwegian archipelago with intense rain, Bailey questioned what it was doing 1,245 miles (2,000 kilometers) away, in Greenland. A 12 months later, she and Hubbard traveled to southeastern Greenland to research the matter.

There, the 2 researchers collected a 49-foot (15-meter) core of firn—dense, compacted snow that step by step turns into glacial ice. Ice cores are nature’s report keepers, and this one documented virtually 10 years price of snow accumulation. By evaluating advanced analyses of the ice core to native climate knowledge, Bailey and Hubbard recognized the ice core part comparable to the 2022 atmospheric river.

“Utilizing high-elevation firn core sampling and isotopic evaluation allowed us to pinpoint the extraordinary snowfall from this atmospheric river,” Bailey defined. “It’s a uncommon alternative to straight hyperlink such an occasion to Greenland ice sheet floor mass stability and dynamics.”

The ice core part revealed that the atmospheric river had introduced 16 billion tons of snow to Greenland, single-handedly offsetting the ice sheet’s yearly ice loss by 8% in simply three days. As acknowledged within the AGU press launch:

The atmospheric river had had pelted Svalbard with rain, however 2,000 kilometers (1,245 miles) away in southeastern Greenland, it delivered snow — and plenty of it. On March 14, 11.6 billion tons of snow fell on the ice sheet, with a further 4.5 billion tons over the subsequent few days. One gigaton of snow roughly equates to at least one cubic kilometer of recent water, which might utterly fill the U.S. capitol constructing greater than 2,200 instances.

The occasion additionally lined the ice sheet with recent, reflective snow, rising the area’s albedo (its capacity to mirror daylight) and setting again seasonal ice soften by virtually two weeks—regardless of 2022’s abnormally heat spring temperatures.

“Sadly, the Greenland Ice Sheet received’t be saved by atmospheric rivers,” Hubbard mentioned. “However what we see on this new examine is that, opposite to prevailing opinions, underneath the precise circumstances, atmospheric rivers won’t be all dangerous information.”

If international temperatures proceed to rise, nonetheless, atmospheric rivers might sooner or later deliver rain as a substitute of snow to Greenland. In reality, Hubbard and Bailey emphasize that extra analysis is required to know each the present and future affect of atmospheric rivers on the Northern Hemisphere’s largest ice mass.

“Atmospheric rivers have a double-edged position in shaping Greenland’s—in addition to the broader Arctic’s—futures,” Bailey concluded.