Oceanographer's Arctic Research Featured in BBC Documentary
An Old Dominion University oceanographer was one of five scientists featured in a documentary that aired recently on Great Britain's BBC, offering insight into why summer sea ice is melting at such a rapid rate in the Arctic.
Victoria Hill, assistant research professor in the Department of Ocean, Earth and Atmospheric Sciences, was one of five scientists who spent six weeks in the barren, frozen landscape where temperatures fall to minus 40 degrees Fahrenheit.
"As a scientist, the reason I am prepared to come out here and be cold is because of the desire to learn and answer burning questions I have about what is going on up here, why the ice is melting as fast as it is," Hill told the "Earth Reporters" program.
Arctic summers are projected to be free of sea ice by the middle of the century, with some studies warning that it could occur in the next decade. Hill told the BBC that the Arctic played a key role in regulating the Earth's climate. "The Arctic drives global circulation and therefore our global climate."
Ocean currents transport vast volumes of water around the planet. They are known as "thermohaline" circulations because they are affected by variations in salinity and temperature. As warm water evaporates, the salinity increases and temperatures fall, resulting in a mass of denser water, which sinks and drives the current.
"If the Arctic gets a lot warmer, we will see a slowing down of the current," Hill said.
The team of five scientists set up camp 1,000 miles north of the Arctic Circle. The Catlin Arctic Survey, funded by the Catlin Insurance Group, funded the creation of the camp between March 1 and late April in the high Canadian Arctic.
The idea was to provide a resource for scientists to study climate change in the Arctic. Data from the early spring in the Arctic is rare, as it is a very difficult environment to survive in, let alone work in. "I had been trying to get some research funded since 2004 to look at the effects of absorption of solar radiation on surface heating and ice melt," Hill said.
Hill said her work focused on how the sun's energy is absorbed, accelerating the ice melt. Specifically, she is studying chromophoric dissolved organic material (CDOM) in Arctic surface waters, and its implications for solar heating.
"Our aim at the Catlin Ice Camp is to determine the sources and sinks of CDOM into and out of the surface mixed layer, and to quantify the impact of this material on solar heating, ice melt and thermal stratification," Hill said.
When plant matter dies and breaks down, some of the organic material that makes up the plant is released as dissolved organic material. A certain fraction of it has light-absorbing, or chromophoric, properties.
"You can think of this like making a cup of tea, the action of pouring hot water over your bag of dead tea leaves breaks down the cell walls, releasing CDOM and turning the water a brown reddish color," Hill said. "The reason that we are interested in CDOM is that it is a strong absorber of solar energy, especially in the UV and blue region of the visible spectrum. It can therefore be an important link between the penetration of sunlight and the warming of Arctic waters."
The documentary is a joint venture between the BBC and The Open University.
This article was posted on: May 25, 2011
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