Arctic Freshwater Dome Could Freeze Europe

The water may spill into the north Atlantic Ocean

  Envisat radar image mosaic covering the Arctic Ocean. The sea ice extent highlighted in blue corresponds to the areas where more than 80 percent of the sea is covered by ice
Sea surface in a particular area of the Arctic Ocean has increased by as much as 15 centimeters (6 inches) over the past 15 years, leading to the formation of a large bulge of freshwater. It is estimated that this region of the ocean contains as much as 8,000 cubic kilometers (1,919 cubic miles) of water.

Sea surface in a particular area of the Arctic Ocean has increased by as much as 15 centimeters (6 inches) over the past 15 years, leading to the formation of a large bulge of freshwater. It is estimated that this region of the ocean contains as much as 8,000 cubic kilometers (1,919 cubic miles) of water.

According to the results of a new study, which appears in the latest online issue of the top journal Nature Geoscience, it would appear that the bulge is being caused by an acceleration of the Beaufort Gyre, an oceanic circulation pattern driven by Arctic winds.

What this implies is that a change in this wind could allow this dome to fall apart, and all the freshwater it contains to spill in the northern sectors of the Atlantic Ocean. This is where the North Atlantic Drift – one of the five major oceanic currents – releases heat from the water

That heat is then moved eastwards by prevailing winds, heating up the majority of the European continent. Last time the current was blocked – back when the sea that contained all the Great Lakes poured into the Arctic Ocean – glaciers moved as far south as the shores of the Mediterranean Sea.

Using data from the European Space Agency's (ESA) ERS-2 and Envisat satellites, experts at the University College London (UCL) Center for Polar Observation and Modeling (CPOM) and colleagues at the National Oceanography Center, both in the UK, managed to discover the bulge in new studies.

Since 2002, researchers explain, the amount of water in the bulge has grown to accumulate as much as 10 percent of all freshwater in the Arctic. This amount is sufficient to affect north Atlantic currents, as well as the Gulf Stream circulation.

“When we looked at our data on a year-to-year basis, we noticed that the changes in the sea surface height did not always follow what the wind was doing, so we thought about reasons why this might happen,” CPOM research fellow Katharine Giles explains.

“One idea is that sea ice forms a barrier between the atmosphere and the ocean. So as the sea ice cover changes, the effect of the wind on the ocean might also change,” adds the scientist, who was also the lead author of the study

As the situation in the Arctic Ocean develops, ESA will continue to use its spacecraft to keep an eye on sea levels. In the near future, this responsibility will be passed on to the Sentinel constellation of satellites. ESA is developing this project as part of its Global Monitoring for Environment and Security (GMES) program.

Comments

By    23 Jan 2012, 10:59 GMT