Greenland ice cap melt accelerating
August 2nd, 2010 by Jim JustA British research team studying the Greenland ice sheet has discovered evidence of a rapidly accelerating rate of melt: the ice sheet in the region they are studying has dropped six meters in just one month.
The shrinking of the glaciers is caused by surface melt, a vicious cycle in which melted ice brings about further thawing of the cap beneath it. Frozen ice has an “albedo”, or reflectivity, of around 80%, whereas open water reflects only around 20% of the sun’s rays. So as the ice melts and turns into water, its surface reflectivity decreases. It then absorbs even more of the heat from the sun, further accelerating the melting.
Black soot particles are also contributing, as shown in this photo in an article at Sky News.
Dr Hubbard shows how soot has pock-marked the iceDr. Alan Hubbard explains:
What you see in there is a bunch of particles of aeolian dust . . . and black soot and just particles that are in the air caused by industry or combustion engines. Because they are dark in color, compared to the ice that surrounds it, which is white, they absorb more of the sunlight and a lot more of its energy, which creates a positive feedback and so they effectively drill down into the surface of the ice sheet.