A new study has found that Greenland ice sheet due to climate change is rapidly losing the ability to buffer its contribution to the rising sea levelS.
Research undertaken by scholars at the York University researchers has found that an extreme melt that occurred in 2012 caused a layer of solid ice, several meters thick, to form on top of the porous firn in the low elevation areas of the ice sheet.
Professor William Colgan, the study’s co-author, said that meltwater couldn’t penetrate vertically through the solid ice layer in subsequent years and instead drained along the ice sheet surface toward the ocean.
Researchers also towed a radar unit behind their skidoos to gather profiles between core sites along a 100-kilometre path from the low elevation ice sheet margin into the high elevation ice sheet interior.
They analysed the firn cores on the spot by cutting them into small sections to quantify their properties, such as their density, so they could compare them with samples collected the following year.
Using unmanned aerial vehicles, Colgan also plans to begin surveying the changes in ice sheet surface reflectance caused by the development of massive ice layers associated with firn cap-off.
There are preliminary indications that firn cap-off is also occurring in the ice caps of the Canadian High Arctic.
The study is published in the Journal Nature Climate Change.