Researchers from the University of Cambridge managed to map the amount of snow in Antarctica on a large scale. They found that this form of precipitation accounts for 57% of all meltwater during the height of summer. The finding suggests that the liquid derived from the melt is 2.8 times greater than estimated in the past.
The ice shelves surrounding Antarctica act as barriers that prevent ice from inland glaciers from entering the oceans. As the climate warms with the arrival of summer, the volume of meltwater increases on the surface of these shelves. Previous work has studied the effects that fluid stored in surface ponds and lakes has on the fracture and collapse of these structures. However, the role played by snow water has not been thoroughly analyzed.
A new and worrying way of melting ice in Antarctica has been discovered
Glaciers located in East Antarctica are the most vulnerable to the newly discovered melting process.
Ian Willis, professor at the Scott Polar Research Institute (SPRI) in Cambridge and co-author of the research, says that “since snow water is more solid than meltwater, it will not cause hydrofractures in the same way that water does. of a lake, but it’s definitely something we need to consider when trying to predict if and how ice shelves will collapse.”
The new analysis published in the journal Nature Geoscience explains that soaked snow absorbs more heat than ice. The feature may have considerable implications for the stability of frozen plates and, eventually, sea level. The phenomenon has been little explored due to technical difficulties, according to Rebecca Dell, a doctor at SPRI and lead author of the study. “We can use satellite images to map meltwater lakes across much of Antarctica, but snowwater is difficult to map because when viewed from a satellite it looks like other things, like cloud shadows.”
Snow water and its role in melting ice
The research team used an artificial intelligence (AI)-based system to address the shortcoming. It used optical data collected between 2013 and 2021 by NASA’s Landsat 8 satellite to train a machine learning model. The system was trained to obtain monthly records of snow and meltwater lakes on 57 Antarctic ice sheets. The tool has the ability to work with more wavelengths of light than the human eye can see. The scientists were able to accurately determine the location and volume of wet snow masses. The resulting information was fed into the AI algorithm to locate all such formations on the continent.
The findings of the exercise indicate that at the peak of the Antarctic summer in January, 57% of the total meltwater from the Antarctic ice shelves It is found in the form of snow waterThe remaining 43% is stored in surface lakes.
“Snowwater has never been mapped on a large scale across all of Antarctica’s large ice shelves, so more than half of all surface meltwater has so far been ignored. This is potentially significant for the process of hydrofracturing, where the weight of meltwater can create or enlarge breaks in the ice,” Dell said.
The authors reiterate that snowwater has a large effect on melt rates that is not accounted for in existing climate models. They warn that projections about the disappearance of the Antarctic ice sheet and the stability of ice shelves could be underestimated.
“In the future, places in Antarctica that currently have no water or snowmelt are likely to begin to change. “As the climate continues to warm, more melting will occur, which could have consequences for ice stability and sea level rise,” Willis said.
The World Meteorological Organization estimates that more than 90% of the world’s oceans experienced heat waves at some point last year. The effects were especially visible in the global set of reference glaciers. The group suffered the largest ice loss ever recorded since 1950. “Antarctic sea ice extent was the lowest ever recorded, with a peak late-winter extent of one million square kilometers below the previous year’s record.” , says the organization.
