UM scientists land grant to study Greenland ice sheet

A core taken from Greenland’s snow layer shows that meltwater has penetrated and refrozen into solid ice. (Courtesy of the University of Montana)

By Missoula Current

The Greenland ice holds secrets to the past and may lend insight to the future.

A new $1.54 million grant from the National Science Foundation will fund a team of University of Montana scientists looking to study the deep layer of compacted snow covering most of island’s ice sheet.

Lead investigator Joel Harper and co-investigator Toby Meierbachtol, both from UM’s Department of Geosciences, received $760,000 for the research, along with $400,000 to charter aircraft.

A collaborator at the University of Wyoming also received $380,000 for the project.

The study will research the development of the snow layer covering Greenland as it melts during the summer months. Meltwater percolates into the underlying snow and refreezes to form deep layers of ice. The melting absorbs heat from the atmosphere, and the refreezing releases heat into the ice sheet.

According to Harper, the icy snow builds up over years to form a layer of dense, compact snow called firn, which can reach up to 90 meters thick. The firn is a key component of the ice sheet and, as its porous structure absorbs meltwater, it changes ice sheet elevation through compaction.

That, Harper said, influences the heat exchanged between the ice sheet and the climate system.

Little is known about the firn layer’s structure, temperature or thickness, and two contrasting theories explain how it has developed over time. One suggests the layer still has the ability to absorb more meltwater while the other suggesting it does not.

Harper said research is critical to understanding whether future melt will percolate downward and refreeze in the empty pore space or be routed off the ice sheet, which has implications for sea level rise and heat transfer from the atmosphere to the ice sheet.

“The mixture of cold snow with scattered pockets of wet snow makes challenging drilling conditions because the cold drill tends to freeze to the wet snow,” Harper said. “That’s why there is so little known about this area.”

The researchers have designed a new type of drill they hope will solve this problem, and they will use the data collected in the holes to guide computer modeling.

The team will visit the ice sheet six times in three years. A modified DC-3 airplane with skis and powerful engines will deliver the researchers near the top of the ice sheet, and from there they will make two long traverses with their equipment.

The project will involve both graduate and undergraduate students.