Atmospheric phenomenon could intensify upcoming Arctic melts

According to a new study, the fate of sea ice may be in the hands of a phenomenon that controls the quantity of warm water flowing into the Arctic Ocean region.

In the vast freezing cold expanses of the Arctic, a weather phenomenon has been captivating climatologists for decades.

The Arctic dipole is a meteorological mystery that has baffled top minds in the field. But new results show that the phenomenon has a greater impact on the Arctic region than previously believed, and that we may soon face unexpected changes in the Arctic.

The dipole phenomenon in some ways resembles our own binary relationship with El Niño and La Niña. In the Northern Hemisphere the rather longer wind patterns of the dipole influence the quantity of the Atlantic’s relatively warm water that will flow northwards into the Arctic Ocean. Currently, the winds appear to be usefully slowing the loss of sea ice, even as atmospheric temperatures rise.

But the new study indicates that the wind conditions could change within a few years, and the Arctic Ocean might then experience rapid sea-ice loss.

The study has attempted to map the wind patterns of the Arctic dipole for the years before it had even been identified. They found that from 1979 to 2006, the Arctic dipole sent massive quantities of relatively warm water from the Atlantic to the Arctic. This led to a dramatic loss of summer sea ice – some one million square kilometres per decade, according to researchers.

Then in 2007 the winds changed, the researchers finding a decreased flow going east of Greenland into the Arctic, the Atlantic waters instead ‘taking a right’ into the Barents Sea north of Russia. The reduced influx of warm Atlantic water slowed the loss of Arctic sea ice to around 70,000km2 per decade.

The researchers have identified an approximately 15-year cycle to this ‘Atlantification’ of the Arctic Ocean, and warn that the system is probably reaching the end of the present cycle.

“The gentle phase has lasted for about 15 years.” says Igor Polyakov from the University of Alaska Fairbanks. “Now it may be coming to an end, if we compare the situation to previous dipole periods.”

If the wind patterns do change, we may be heading for a sudden increase in Arctic ice melting, along with feedback loops in which the larger open areas of water encourage still more ice melt.