In the last twenty years, Ice loss from Greenland has increased due to increased surface melting, resulting in increased water distribution to the ocean. Now new research confirms that the ice sheet is melting much faster than previously thought, exacerbating sea level rise across the planet.
Researchers noted that: this trend could result in global sea level rise six times greater than current climate models predict at the end of the century. The study, published in the journal Nature, is based on an analysis of the Northeast Greenland Ice Stream (NEGIS). A large ice sheet covering about 80% of Greenland’s surface. It is the second largest ice sheet in the world after the Antarctic ice sheet. It covers an area of 1.71 million km² and has a length of approximately 2,400 kilometers from north to south and a maximum length of 1,100 kilometers from east to west.
New estimates show that The meltdown of this sector alone could raise sea level by as much as 1.5 centimeters by 2100.It is equivalent to the total contribution of the Greenland ice sheet over the last 50 years. To arrive at these findings, the international team combined satellite imagery and numerical modeling with GPS data collected over the past decade.
In 2012, the entry of warm ocean currents, The collapse of the floating extension of the Zachariae Isstrom Glacier. Due to this event, the ice flow accelerated, causing a rapid wave of ice thinning that spread upstream.
The researchers found that this thinning extends 200 to 300 km inland from the Greenland coast. Other Greenland glaciers may suffer the same fate.
“Many glaciers have been thinning near the boundary in recent years. GPS data has helped us pinpoint how inland these changes initiated near the coast. If this is true, The contribution of ice dynamics to the total mass loss in Greenland will be greater than what current models suggest.” stated study co-author Mathieu Morlighem, a professor of Earth Sciences at Dartmouth College, United States.
unexpected effect
Study, from 2011 to 2021 Northeast Greenland Ice Stream (NEGIS) dropped to 3 meters. This will continue at an accelerated pace throughout this century.
“The glaciers we studied shrank each year, and we predict this will continue for the next decades and centuries. Under current climate change, it is difficult to understand how this reversal can be stopped.The paper’s first author warned Shfaqat Abbas Khan of the Technical University of Denmark.
Although the winter of 2021 and the summer of 2022 were particularly cold, the NEGIS glaciers continued to recede. Northeast Greenland is an arctic desert where precipitation is less than 25 millimeters per year. some places. This means that not regenerating enough to compensate for the ice sheet melting.
However, it is not easy to estimate how much ice has melted and how deep the ice sheet has gone. The interior moves less than a meter per year.
“Models mostly fit observations in front of the ice sheet, where there is a lot of stuff that is easily accessible and visibly. Our data show us that what we see at the front has reached the heart of the ice sheet.Khan contributed.
As more precise observations are included in the models, the estimates of global sea level rise of 20 to 76 centimeters by 2100, projected by the UN Intergovernmental Panel on Climate Change, will likely need to be adjusted upwards.
“we foresee profound changes in global sea levels, more than current models predict. Data collected in the vast interiors of ice sheets, such as those described in our research, helps us better represent the physical processes involved in numerical models, and in turn provides more realistic estimates of global sea level rise.” Rignot, professor of Earth systems science at the University of California.
Reference work: https://www.nature.com/articles/s41586-022-05301-z
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