Tuesday, January 29, 2013

A MEADOW OF FROST 'FLOWERS' IN THE OCEAN


Graduate student Jeff Bowman first saw these ‘flowers’ between 3 and 4am from the deck of a ship returning from the North Pole. The temperature had just dropped and when dawn broke he was able to see them much more clearly and for much farther. They appeared to be growing in the cold and dry air all across the surface of the water. He was told they were frost flowers.

Frost flowers are like ice sculptures and they grow on the border between the sea and air. Bowman’s colleague Matthias Wietz took this image on September 2, 2009 when the air was extremely cold and dry; colder than the surface of the ocean. When the conditions in the air are that different from that of the sea, the dryness in the air ‘pulls’ moisture from bumps in the ice which then vaporises. The air gets humid for a little while and the cold makes the water vapour heavy. As the air needs to release the excess weight, the air turns the vapour back into ice, crystal by crystal, creating ‘frost flowers’ up to 7 centimetres high.

The ‘flowers’ themselves suck up seawater and concentrate the salt within; they contain three times the salinity of the ocean. Bowman and his colleagues took a frozen flower and let it melt. Only one to two millilitres of water resulted, though each frost flower hosted about one million bacteria.

As the poles warm, there may be more and more of these frost flower meadows as there will be more open sea turning to thin ice in winter.


http://www.npr.org/blogs/krulwich/2012/12/17/167469845/suddenly-theres-a-meadow-in-the-ocean-with-flowers-everywhere

Image Credit: Matthias Wietz



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