Wow, this is cool. H/t Felicity Barringer at the New York Times.
I find these sorts of papers delightful because they take a problem that has engaged many brilliant people -- Why is the Arctic melting faster than climate models suggest it should? -- and suggest a simple correction, backing up that intuition with data.
In this case, the powerfully simple idea is ice is not totally opaque. As anyone who has ever looked at a piece of ice knows, thin ice lets more light through, thicker less. So with the aid of sensors under the ice, the authors have shown that the thinning of the ice sheet, the melting and re-freezing, under global warming, results in more thin ice and less thick ice. Boom! Another positive feedback; more energy is absorbed, the Arctic warms fast and the ice melts faster.
Seems almost too basic, doesn't it? Elegant idea, elegant demonstration.