European Satellites detect abundance of fresh water in the Arctic
25 Jan 2012
European satellites show that a large dome of fresh water has been building up in the Arctic Ocean over the last 15 years.
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Arctic Ocean mean sea-surface with respect to the geoid for the past 15 years of satellite radar altimetry data. The Beaufort Gyre is the yellow/orange dome in the Western Arctic.
Credits: CPOM/UCL/ESA/Planetary Visions.
Researchers from the Centre for Polar Observation & Modelling (CPOM) at University College London, and the National Oceanography Centre (NOC), made their discovery using ESA’s ERS-2 and Envisat satellites. They measured sea-surface height over the western Arctic over a 15-year period, from 1995 to 2010.
The results are remarkable: since 2002, the sea surface in the studied area has risen by about 15 cm, and the volume of fresh water has increased by some 8000 cubic km – around 10% of all the fresh water in the Arctic Ocean.
If the wind changes direction, as happened between the mid-1980s and mid-1990s, the water could spill out into the rest of the Arctic and then perhaps even the north Atlantic. This could cool Europe by slowing down a key ocean current derived from the Gulf Stream, which keeps the continent relatively mild compared with countries at similar latitudes.
"Satellite data has shown us that a dome of fresh water has been building up in the western Arctic over the past 15 years, due to the wind. Our findings suggest that a reversal of the wind could result in the release of this fresh water to the rest of the Arctic Ocean and even beyond," said Dr Katharine Giles from CPOM, lead author of the study, published in Nature Geoscience.
"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," she added.
More information about UK involvement in Envisat and ERS2 is available in the missions section of the website.
