Oceanographer Virginia Hill's important research on Arctic bacteria

Causing positive feedback?

http://tinyurl.com/3fkd6ke

"In the last ten years, we've just seen massive ice melts every single year, and right now, 2007 was the greatest ice melt on record," explains Hill.

Other scientists have focused on the effect of warming air on the ice, but Hill believes that something within the water itself -- a special kind of bacteria -- is causing the water to absorb more sunlight and accelerate melting. She spent six weeks doing research in the Arctic, collecting core samples which may contain what she calls "color dissolved organic material."

Hill says this material acts as a dye that darkens the water and attracts sunlight, and the warmer water more rapidly melts the ice.

“You can also think of going out on a hot day wearing a white t-shirt," says Hill. "The white color is going to reflect a lot of light. Or going out and wearing a black t-shirt, and you’ll get much hotter if you wear that black t-shirt because that dark color will absorb the sunlight much more rapidly than the white one.”

Hill found that this dark substance in the water is produced by algae and stored in the ice. Because so much ice is melting, a lot of this dark substance is entering the water, which makes the water even more able to absorb sunlight and heat.