Greenland’s glaciers are melting 100 times faster than previously calculated, according to a new model that takes into account the unique interaction between ice and water in the island’s fjords.
New mathematical representation of glacial melting factors in the latest observations on how ice is eaten away from steep vertical faces at the ends of glaciers in Greenland. First, the scientists used a model developed in Antarctica (opens in new tab)Where glacial tongues float on top of seawater – a very different arrangement.
“For years, people took melting rate models for Antarctic floating glaciers and applied Greenland (opens in new tab)of vertical glacier fronts,” lead author Kirsten Schultz (opens in new tab)a research associate at the Oden Institute for Computational Engineering and Science at the University of Texas at Austin Statement (opens in new tab), “But there is more and more evidence that the conventional approach produces very low melt rates on Greenland’s vertical glacier fronts.”
The researchers published their findings in September in the journal Geophysical Research Papers (opens in new tab),
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The researchers already knew that their Antarctica-based understanding of Arctic glaciers was not a perfect match. But it is difficult to get close to the edges of Greenland’s glaciers, because they are located at the ends of fjords – long, narrow inlets of seawater surrounded by high cliffs – where warm water erodes the ice. According to the researchers, this dramatically leads to calving events, where chunks of ice fall into the water with little warning, creating mini-tsunamis.
Researchers led by physical oceanographer Rebecca Jackson (opens in new tab) Researchers at Rutgers University are using robotic boats to get close to these dangerous icebergs and take measurements. They have done so at the Leconte Glacier in Alaska as well as at the Kangerlussup Syrmia in Greenland. (An upcoming mission led by scientists at the University of Texas at Austin will send a robotic sub to the faces Three West Greenland Glaciers. (opens in new tab)) Jackon’s measurements show that Antarctica-based models largely underestimate the melting of Arctic glaciers. For example, it is disappearing 100 times faster than the LeConte model predicts.
The mixing of cold freshwater and warm seawater from glaciers causes ocean currents near the glaciers and far into the ocean, meaning the melting has far-reaching effects. The Greenland ice sheet is also important for sea level rise; Greenland’s ice holds enough water to raise sea level by 20 feet (6 m).
The new model uses the latest data from near-glacial missions, along with a more realistic understanding of how the glaciers’ steep, cliff-like faces affect ice loss. The results are consistent with Jackson’s findings, which show melting 100 times more than the old model predicted.
“The results of ocean climate models are highly relevant to mankind in predicting trends associated with climate change, so you really want to get them right,” Schulz said. “This was a very important step in improving climate models.”
Originally published on LiveScience.