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| The Coast Guard Cutter Healy breaks ice ahead of the Canadian Coast Guard Ship Louis S. St-Laurent during an Arctic expedition, in this August 24, 2009 [Credit: Reuters//U.S. Coast Guard/Patrick Kelley] |
The volume of fresh water has increased by about 10 percent of all the fresh water in the Arctic Ocean. The fresh water comes from melting ice and river run-off.
The rise could be due to strong Arctic winds increasing an ocean current called the Beaufort Gyre, making the sea surface bulge upwards.
The Beaufort Gyre is one of the least understood bodies of water on the planet. It is a slowly swirling body of ice and water north of Alaska, about 10 times bigger than Lake Michigan in the United States.
Some scientists believe the natural rhythms of the gyre could be affected by global warming, which could have serious implications for the ocean's circulation and rising sea levels.
The Beaufort Gyre is a great clockwise ocean circulation in the western Arctic Ocean. Accelerated by strong Arctic winds, the sea surface bulges upwards. Measurements from ESA’s ERS and Envisat missions show that, since 2002, the surface has risen by about 15 cm and the volume of fresh water has swollen by approximately 8000 cubic km - around 10% of all the fresh water in the Arctic Ocean [Credits: CPOM/UCL/ESA/Planetary Visions]
Climate models have suggested that wind blowing on the surface of the sea has formed a raised dome in the middle of the Beaufort Gyre, but there have been few in-depth studies to confirm this.
If the wind changes direction, which happened between the mid-1980s to mid-1990s, the pool of fresh water could spill out into the rest of the Arctic Ocean and even into the north Atlantic Ocean, the study said.
This could cool Europe by slowing down an ocean current coming from the Gulf Stream, which keeps Europe relatively mild compared with countries at similar latitudes.
"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 Katharine Giles at UCL's Center for Polar Observation and Modelling and lead author of the study, published in the journal Nature Geoscience.
The team plans to investigate further the relationship between sea-ice cover and wind changes.
Source: Reuters [January 22, 2012]