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Visiting and monitoring South Greenland dark ice

I’m spending a week flying out of Narsarsuaq, south Greenland, with colleague Dr. Robert Fausto, to maintain climate stations equipped to monitor surface ice melt in great detail. Part of the Danish PROMICE network, the stations obtain surface energy and mass budget closure. The closure means that calculated melt matches with observed melt.

coming in to land at a PROMICE climate station, one of 22 on Greenland ice operated by GEUSPhoto J. Box.

Flying across this vast space and on the ground, I’m is struck by how abundant snow algae and other light absorbing impurities can be. The low reflectivity impurities amplify the effects of the increasing melt season. Increased melt means a shorter duration of highly reflective snow cover. The prolonged exposure of an impurity-rich bare ice surface multiplies melt rates. I’ve calculated that without this albedo feedback, the increase in melt rates would amount to half of what’s observed. Some of this feedback is due to ice crystal rounding. Some is due to the impurities. Measuring the relative importance of metamorphic and impurity driven albedo reduction is a subject of our work.

boots on the ice offer a close look (and to sample) impurities concentrating at the surface. The fact is, much of this dark material is from cyanobacteria and blue-green algae. Photo J. Box.

puddles often form with this kind of algal slick’. Photo J. Box.

It’s exciting to be working with Dr. Marek Stibal who studies the microbial environment on Arctic ice. Together with his data, the surface energy exchange data from the PROMICE climate stations and Danish Meteorological Institute’s regional climate modeling (Follow @Greenlandsmb), we have a powerful approach to unravel more detail from the melt story in Greenland.

South Greenland Dark Ice. Photo J. Box.

Snow accumulates in crevasses forming snow bridges that one would rather fly over. In between, impurity-rich ice absorbs up to 80% of the Sun’s energy. Photo J. Box.

Surface melt water mingles with impurity rich Greenland ice. Photo J. Box.

Robert Fausto maintains a climate station equipped to measure downward and upward solar energy, among many other climate parameters as part of the Danish PROMICE network (Follow @PromiceGL). Photo J. Box. (Follow @Climate_Ice)

About the author Jason Box

Dr. Jason Box has been investigating Greenland ice sheet sensitivity to weather and climate as part of 23 expeditions to Greenland since 1994. His time camping on the inland ice exceeds 1 year. Year 2012 brought a deeper level of insight as the scientific perspective shifts to examine the interactions ice with atmospheric and ocean systems, including the role of fire in darkening the cryosphere. As part of his academic enterprise, Box has authored or co-authored 50+ peer-reviewed publications related to Greenland cryosphere-climate interactions. Box instructed climatology courses at The Ohio State University 2003-2012. Box is now a Professor at the Geological Survey of Denmark and Greenland (GEUS). Box was a contributing author to the Nobel Peace Prize-winning Intergovernmental Panel on Climate Change 2007 4th assessment report. Box is also the former Chair of the Cryosphere Focus Group of the American Geophysical Union.

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