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 GEUS. Photo 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)
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2 comments:
In the photo showing the crevasses that are filled in / bridged over by snow, do you have an estimate of the width of the crevasses? I'm trying to determine what sort of scale I'm seeing in the photo. I am an artist whose work explores our relationship with nature. A new project I'm exploring is to create a number of paintings that would be painted at a given scale relative to the scene being depicted (with all of the images being from the arctic and antarctic). By using images that have an abstract quality, and no way to determine scale, the image will serve as a metaphor for how abstract the scale of clime change is to most people. Because they haven't been seriously impacted, they don't really grasp that it is happening. ANd that the changes of enormous (which is why at least one of the painting in this project will be enormous!). Thanks for any info you can provide!!
Best wishes,
Aaron Lish
http://www.aaronlish.com
http://aaronlishart.tumblr.com
https://www.facebook.com/pages/Aaron-Lish/474945359278321
http://www.saatchiart.com/aaronlish
Try jboxgreenland@gmail.com
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