Scientists believe that the more severe winters suffered by the UK over the past few years are a result of disappearing ice in the Arctic sea. A reduction in sea ice, they explain, could be the reason for the colder winters, which up until recently have been insulating temperature changes in the sea from the atmosphere.
However, as the ice has been decreasing, so too has its control over the temperature of the water it used to hide.
“Some climatologists believe the absence of sea ice north of Siberia last autumn allowed the warmer open ocean to heat the atmosphere, resulting in changed wind patterns and the development of a “blocking” atmospheric high pressure system over Siberia,” explains Dr Tom Rippeth of Bangor University. “This then results in cold air being channelled south from the Arctic, over northern Europe.”
On top of that, scientists have only recently discovered that the Arctic Ocean is not as tranquil as had previously been assumed by oceanographers. Yueng-Djern Lenn, Chris Old and Tom Rippeth of the Bangor University’s School of Ocean Sciences have taken new measurements that show occasional bursts of turbulence beneath the Arctic sea ice which helps to mix adjacent water layers together. Mixing of water layers like this can bring heat from the ocean interior to heat the underside of the sea ice covering it, whilst in open water mixing helps to take heat from the surface layers into the interior.
Their new findings suggest that, with no sea ice insulating the sea surface from the atmosphere, there could be a lot more mixing going on.
“These results are highly significant as they are helping us to understand the role of sea ice in the Arctic and in particular how it impacts heat exchange between the ocean interior and the atmosphere,” said Dr Tom Rippeth.
“They imply that the Arctic Ocean will become much more turbulent in a warming world. We are already seeing a big reduction in the extent of sea ice cover, particularly during the summer months, and so there is a lot more mixing going on. What we could be seeing is the Arctic coming out of hibernation, and the question we must consider is what impact this will have on our climate here in the UK.”