New data on the melting of frozen masses provide even more reason to worry about the future of the planet. this Ice loss from the Greater Greenland basin is happening much faster and could contribute to sea level rise up to six times a year 2100 More so than climate models currently reflect, according to a study led by researchers at Dartmouth College, the University of California, and the Technical University of Denmark (DTU) in the United States.
Publishing their work in the journal ‘Nature’, the authors discovered that the Northeast Greenland Ice Current (NEGIS) could add more than a centimeter of water to sea level by the end of this century. equal to the contribution of the entire Greenland ice sheet over the last 50 years.
The study combined data from satellites and digital models with GPS data. collected in the harsh interior of Greenland over the last decade. in 2012 entry of warm ocean currents caused the floating expanse to collapse of NEGIS, which accelerated the ice flow and triggered a rapid wave of ice thinning that spread upstream. The researchers found that this thinning extends 200-300 kilometers inland from the Greenland coast, and that other Greenland glaciers may suffer the same fate.
“GPS data helped us detect how far these changes spread inward Co-author Mathieu Morlighem, Evans Family Distinguished Professor of Earth Sciences at Dartmouth, led the development of numerical models for the study that simulates the flow of ice from within the ice sheet to the shore. .
Global mass loss in Greenland will be greater
“The Greenland ice sheet is not necessarily more unstable than we thought, but it may be more sensitive to changes in the coastal environment,” explains Morlighem. “If this is true, the contribution of ice dynamics ice to global mass loss in Greenland will be larger than current models suggest“.
The study is based on data collected by a team led by first author Shfaqat Abbas Khan, Professor at DTU Space, using a network of GPS stations extending behind the Nioghalvfjerdsfjord Gletscher and Zachariae glaciers to NEGIS. and away from the world.
Morlighem and co-author Youngmin Choi, now a former graduate student in Morlighem’s research group at UC Irvine NASA Jet Propulsion Laboratorycompared GPS data collected from the ice sheet with numerical models they had developed to capture the dynamic response of NEGIS following the collapse of the floating stretch of the Zachariae Isstrom Glacier in 2012.
They tested their model with various friction laws until their results matched the ice sheet data. They then ran the model into the future and found that NEGIS could lose six times more ice than current climate models predict.
Whole basin inspects
“We can see that the entire basin is thinning and the surface velocity is increasing. The glaciers we study have retreated inland each year, and we predict this will continue for decades to come,” Khan said. Under the current climate forcing, it’s hard to envision how this retreat could be stopped.”
Although the winter of 2021 and the summer of 2022 were particularly cold, the glaciers in NEGİS continued to retreat. Northeast Greenland is an arctic desert in which precipitation in some places they reach 25 millimeters per year. This means that the ice sheet does not regenerate enough to compensate for the melting.
However, estimating the amount of ice lost and the depth of the process is not easy. Moving less than a meter per year, the interior of the ice sheet is difficult to control, limiting its ability to project accurately.
“The models fit the observations mostly to the front of the ice sheet, which is easily accessible and where there is a lot of visibly much. Our data shows us that what we see in the front is reaching the front of the ice sheet,” Khan said.
Deep changes in global sea level
Co-author Eric Rignot, professor of Earth systems science at the University of California at Irvine, said it is likely because more precise observations of the change in ice velocity are included in the models. global sea level rise forecasts need to be adjusted upwardsl, like the 22-98 centimeters predicted for 2100 by the UN Intergovernmental Panel on Climate Change.
“We expect more profound changes in global sea level than currently predicted by current models. Rignot points. Data collected in the vast interiors of ice sheets, such as those described in our research, help us better represent the physical processes involved in numerical models, and in turn provide more realistic estimates of sea level rise worldwide.”
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Contact information of the environment department: crisisclimatica@prensaiberica.es
Source: Informacion
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