Topographic map of the Arctic Ocean and the surrounding islands
Scientists at University College London and the UK’s National Oceanography Centre have discovered that a large dome of water has been building up in the western Arctic Ocean over the past 15 years. And if a change in wind direction occurs, this could cause the water to spill into the north Atlantic, potentially cooling Europe as a result, according to the European Space Agency (ESA).
Scientists from the Centre for Polar Observation at University College London and at the UK’s National Oceanography Centre used satellites provided by the ESA for their research. Their findings have just been published in Nature Geoscience.
They say the freshwater stored in the western Arctic Ocean increased by 8,000 km3 between the mid-1990s and 2010.
They made the discovery by looking at changes in the sea surface height measured by the ESA’s satellites ERS-2 and Envisat.
The scientists have indicated that the dome of water could have amassed due to strong Arctic winds accelerating a large ocean circulation known as the Beaufort Gyre, causing the sea surface to bulge.
And a change in wind direction could lead to the release of this fresh water into the rest of the Arctic Ocean and perhaps even beyond that, they have revealed.
The ESA said it could slow a key ocean current, stemming from the Gulf Stream, and subsequently cool Europe.
Dr Katharine Giles from the UCL Centre for Polar Observation & Modelling, spoke about how temperatures in the Arctic get down to about -30°C in winter, while in summer they rest at about 0°C.
She said that when the scientists looked at their data on a year-to-year basis, they noticed that the changes in the sea surface height did not always follow what the wind was doing, so they then delved into reasons why this might happen.
“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,” said Giles. “Our next step is to look into how changes in the sea ice cover might affect the coupling between the atmosphere and the ocean in more detail to see if we can confirm this idea.”
The Arctic Ocean itself covers about 14m sq km.
