A slush puddle nearly twice the size of California appeared in Antarctica in January of 2016, according to a new paper in Nature Communications that marks one of the first times scientists have documented the fact that Antarctica is actually melting from above because of warm air.
Researchers have known for years that warming ocean water is melting the coastal ice shelves of the West Antarctic Ice Sheet (WAIS). But surface melt is harder to track and understand. In this study, scientists found that warm air is also melting the WAIS from above.
"This is the first time that detailed measurements have been made available for what's going on in the atmosphere," said co-author David Bromwich, a research professor at Ohio State University, in a phone interview.
The melting that scientists saw in 2016 was likely caused by a super strong El Niño, a climate cycle when Pacific Ocean surface water warms up to unusual temperatures around the Equator. Other effects include warmer-than-average temperatures in parts of Canada and the US.
Last year El Niño was very intense, according to Bromwich, and in the future we could be seeing a lot more of extremely intense El Niño events.
As for Antarctica, talk about being attacked from all angles.
Using satellite-based melt data and other tools like laser radar to measure radiation from the Sun, researchers determined that an area of roughly 300,000 square miles, which is just about as large as the state of Texas, and affected a large portion of the Ross Ice Shelf within the WAIS, turned from solid ice to a slushy mix of snow and water.
According to Bromwich, extra-intense El Niño events are only expected to increase in frequency as a result of climate change, which doesn't bode well for the future of the massive Antarctic ice sheet. The researchers predicted that with more of these events will come more major melt events in the same area.
"In the future, we could be seeing melting from the top of the ice shelves," said Bromwich.
If it completely collapsed, sea levels would rise 11 feet, according to Bromwich, and miles upon miles of the southeast US coastline would flood.
Whether or not this singular event will have a small or great impact on the future melting of the ice sheet, it's becoming abundantly clear that the poles are greening, sea levels are rising and countries need to do more to prepare themselves for what's to come.
"This is a glimpse of what the future might bring," Bromwich said. "So rather than being a rare event it's possible that we could see a lot of this in the future."
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