Arctic sea ice has not only declined over the past decade but has also become distinctly thinner and younger - mainly thin, first-year ice floes which are extensively covered with melt ponds in the summer months where once meter-thick, multi-year ice used to float.
Researchers have now measured the light transmission through the Arctic sea ice for the first time on a large scale, enabling them to quantify consequences of this change. They come to the conclusion that in places where melt water collects on the ice, far more sunlight and therefore energy is able to penetrate the ice than is the case for white ice without ponds.