Cold ocean water could slow island ice loss until 2050, after which warming and melting could acceleratePeer-reviewed publications
Federation of Geometry of the United States of America
American Geophysical Union
February 15, 2022
AGU issue number 22-11
For immediate release
This press release and accompanying multimedia are available online at: https://news.agu.org/press-release/blue-blob-near-iceland-could-slow-glacial-melting/
“Blue Blob” near Iceland could slow down thaw
Cold ocean water could slow island ice loss until 2050, after which warming and melting could accelerate
AGU Press Office:
Rebecca Dzombak, +1 (202) 777-7492, [email protected] (UTC-5 hours)
Contact information for researchers:
Brice Noël, University of Utrecht, [email protected] (UTC + 1 hour)
WASHINGTON – A cooling body of water in the North Atlantic near Iceland, nicknamed the “Blue Blob,” has likely slowed the melting of the island’s glaciers since 2011 and may continue to do so. ice loss until about 2050, according to a new study.
The origin and cause of the Blue Blob, located south of Iceland and Greenland, is still under investigation. The coldest wave was most prominent during the winter of 2014-2015 when the sea surface temperature was around 1.4 degrees Celsius (2.52 degrees Fahrenheit). colder than usual.
The new research used climate models and field observations to show that the cold water patch cooled the air over Iceland enough to slow ice loss starting in 2011. The model predicts cooler water will persist in North Atlantic, without using Iceland’s glaciers until around 2050. Ocean and air temperatures are projected to increase between 2050 and 2100, leading to a rapid increase in melting rates .
While cooler water in the North Atlantic provides a temporary respite for Iceland’s glaciers, the authors estimate that without steps to mitigate climate change, glaciers could lose one-third of the current ice mass by 2100 and disappear by 2300. If the country’s 3,400 cubic kilometers (about 816 cubic miles) of ice melted, sea levels would rise 9 millimeters (0.35 inches).
“Ultimately, the message remains clear,” says Brice Noël, a climate modeler specializing in ice sheets and glaciers at the University of Utrecht. “In the end, the message was clear. “The Arctic is warming rapidly. If we want to see glaciers in Iceland, then we have to curb warming.”
The article was published in the journal AGU . Geophysical research letter, which publishes high-impact, short-format reports with immediate impact on all disciplines of Earth and space sciences. Its findings could help scientists better understand the ocean’s indirect effects on glaciers.
“It is important to have an idea of the possible responses in the Arctic because this is an area that is changing very quickly,” says Noël. “It’s important to know what we can expect in a warmer climate in the future.”
The Arctic is warming
Nowhere on Earth is it warming as quickly as the Arctic. Recent studies report that this area is warm up four times faster compared to the global average. Iceland’s glaciers shrank steadily between 1995 and 2010, losing an average of 11 gigatons of ice per year. However, starting in 2011, Iceland’s melting rate slowed, resulting in about half the loss of ice, or about 5 gigatons per year. This trend was not seen in the larger, nearby glaciers across Greenland and Svalbard.
Noël and his colleagues investigated the cause of this slowdown by estimating the mass balance of the glaciers – they either grew or melted every year from 1958 to 2019. They used models High-resolution regional climate modeling works on a small scale of glaciers in Iceland to estimate how much snow glaciers receive in winter and how much ice is lost due to seasonal meltwater summer. The researchers found that cooler waters near the Blue Blob were associated with observations of lower air temperatures over Iceland’s glaciers and coincided with a slowdown in thaw since 2011 .
Some researchers have suggested that the Blue Blob is part of a normal Arctic sea surface temperature variation. Remarkable, especially the cold winter in 2014 and 2015 led to record coolingcausing deep, cold water to rise, even as ocean temperatures around the region warm due to climate change.
Prior to the Blue Blob, a long-term cooling trend in the same region, known as the Atlantic Warming Hole, had brought sea surface temperatures down. about 0.4 to 0.8 degrees Celsius (0.72 to 1.44 degrees Fahrenheit) in the last century and may continue to cool the region in the future. One possible explanation for the Warm Hole is that climate change has slowed down the Atlantic Meridian Cycle, an ocean current that carries warm water from the tropics to the North Pole, thereby reducing the heat transfer to the area.
The end of the glaciers in Iceland?
Noël predicted Iceland’s future climate by combining a similar regional climate model with a global climate model to predict how ocean temperatures in the North Atlantic would affect the number of of glaciers until 2100, under a rapid warming scenario. Models predict that the North Atlantic near Iceland will be in a state of cooling, slowing – and possibly even temporary halting – ice loss from glaciers by the mid-2050s.
The authors verified that the models accurately reproduced the mass of the glaciers using nearly 1,200 snow depth measurements collected between 1991 and 2019 by colleagues at the University of Iceland and Satellite measurements of the elevation and extent of the glaciers were made between 2002 and 2019 by fellow authors at Delft University of Technology.
“I think their analysis is very thorough,” said Fiamma Straneo, a physical oceanographer at the Scripps Institution of Oceanography who was not involved in the study. “They have a really modern regional atmospheric model to look at the variability of the glaciers.” Straneo thinks this approach could be used to understand changes in other glaciers that occur on land, such as in the Himalayas and Patagonia. “There’s a lot of active research on ending land-based glaciers because they’re one of the biggest contributors to sea level rise right now.”
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This study is published with open access and is freely available. Download a PDF copy of the article here. Neither the newspaper nor this press release are embargoed.
Newspaper headline:
“Cooling in the North Atlantic is reducing the mass loss of Iceland’s glaciers”
Author information:
- Brice Noël (corresponding author), Michiel R. van den Broeke, Utrecht Institute of Atmospheric and Marine Research, University of Utrecht, Utrecht, Netherlands,
- Guðfinna Aðalgeirsdóttir, Finnur Pálsson, Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland
- Bert Wouters, Utrecht Institute of Marine and Atmospheric Research, University of Utrecht, Utrecht; Department of Geosciences & Remote Sensing, Delft University of Technology, Delft, Netherlands
- Stef Lhermitte, Jan M. Haacker, Department of Geosciences & Remote Sensing, Delft University of Technology, Delft, Netherlands
JOURNEYS
Geophysical research letter
DOI
ARTICLE TITLE
Cooling in the North Atlantic is reducing the mass loss of Iceland’s glaciers
ARTICLE PUBLICATION DATE
January 24, 2022
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