How did the Arctic ocean get covered in thousands of delicate ice flowers?S

On a research trip to the Arctic, biologist Jeff Bowman witnessed a bizarre scene. Overnight, surface of the ocean had sprouted thousands and thousands of what seemed to be delicate ice flowers. They floated on the surface, sparkling like improbable geophysical artifacts. What caused it?

NPR's Robert Krulwich reports:

They aren't flowers, of course. They are more like ice sculptures that grow on the border between the sea and air. On Sept. 2, 2009, the day Jeff's colleague Matthias Wietz took these pictures, the air was extremely cold and extremely dry, colder than the ocean surface. When the air gets that different from the sea, the dryness pulls moisture off little bumps in the ice, bits of ice vaporize, the air gets humid - but only for a while. The cold makes water vapor heavy. The air wants to release that excess weight, so crystal by crystal, air turns back into ice, creating delicate, feathery tendrils that reach sometimes two, three inches high, like giant snowflakes. The sea, literally, blossoms.

Read more on Krulwich's blog.