“We might possibly see the kind of weather pattern that’s been causing our big freeze moment becoming a bit more of a frequent event,” said Dr John King at the British Antarctic Survey (BAS), which also conducts Arctic research.
A disturbance in the polar vortex and the jet stream, that normally blows west to east, is pushing cold air further south than normal and drawing warm air further north.
“We’re seeing this huge meander in the jet stream, which has been bringing the cold Arctic air down towards the UK. On the other side of the meander it’s been bringing relatively warm air up towards Greenland and into the Arctic and that’s that’s why we’ve been seeing these really unusual conditions in the Arctic in that sector,” King said.
A long-term shrinking of sea ice on the Arctic Ocean, linked to global warming, exposes warmer water below that releases more heat into the atmosphere. That in turn may be disrupting the high altitude jet stream.
“There is now much less sea ice in the Arctic than there was previously and we can only account for this if we take human induced warming into account. Now there’s also been some changes in the sea ice covering the Arctic Ocean during the winter and there’s some evidence that if the sea ice cover changes in some sectors of the Arctic during the winter then that can promote the kind of weather pattern that we’re seeing at the moment,” said King, the Science Leader for Atmosphere, Ice and Climate at BAS.
Europe is experiencing some of the worst weather it’s seen for thirty years, forcing Britain to call in the army to rescue hundreds of drivers stuck in the snow and to transport National Health Service workers. Roads were closed, schools shut and flights cancelled across Britain.
The World Meteorological Organization said the chill in Europe was caused by a “Sudden Stratospheric Warming” above the North Pole that led to a split in the polar vortex, a cold area of air above the Arctic that spilled cold south.
“We’re becoming increasingly aware of the central role that the polar regions play in controlling global climate and regional weather and if we’re to understand how these extremes may change into the future clearly we’ve still got a lot of work to do and in understanding how how what’s going on in the Arctic can affect what’s going on over the UK and Western Europe,” said King.
Under the 2015 Paris climate agreement, almost 200 nations agreed to limit a rise in temperatures to “well below” 2 degrees Celsius (3.5 Fahrenheit) above pre-industrial times, while pursuing efforts to limit it to 1.5C (2.7F).