Will Loss of Arctic Sea Ice Cause More ‘Snow on Ice’ in Greenland?

Nicolàs Young collects a surface rock sample from a glacial erratic in Greenland. Erratics sitting unshielded on the Greenland bedrock are selected for sampling. Using a multi-cosmogenic technique, isotopes beryllium-10 (half life of 1,387,000 years) and aluminum-26 (half life of 720,000 years) are used in tandem to calculate the time of rock exposure and thus when the Greenland Ice sheet retreated from this position. (Photo: Margie Turrin)

Nicolàs Young, an assistant professor at Columbia’s Lamont-Doherty Earth Observatory, Jason Briner, a professor at the University of Buffalo, and an assortment of fellow scientists and graduate students are gearing up to spend a third summer camping along the Greenland ice margin.

As part of an ambitious multi-institutional and cross-disciplinary project, NSF-funded Snow on Ice, Young and Briner are collecting lake sediment, rock, water and plant samples that will be used to tease apart linkages between sea ice on the Arctic Ocean, atmospheric uptake through increased evaporation and changes in snowfall on the Greenland Ice Sheet. The fieldwork will be centered in southwest Greenland where climate sensitivity during past interglacials was the greatest. The resulting data will be combined with new isotopic ice core work and updated subglacial topography, for delivery to two sets of modelers on the project team to feed into a set of nested models.

The project goal is to look at the last 8000 years in Western Greenland, spanning back into the last Thermal Maximum when temperatures were approximated at 1-2°C warmer than today and the ice sheet was smaller. It is difficult to constrain the dimensions of an ice sheet that is smaller than present as the traditional markers that are used for evidence are covered over but we will tackle it with the multiple instrument approach described above. The data will be used as a proxy for what might happen in Greenland’s future, addressing with increased certainty whether reductions in Arctic sea ice in the past triggered a feedback loop that caused increased precipitation falling as snow, and resulted in stabilizing the Greenland ice Sheet even in a warming climate.

Explore a project photo essay on State of the Planet and visit the Snow On Ice website to learn more about this project.

— Margie Turrin, Earth Institute

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