A winter of strange weather and turbulent transatlantic flights in the northern hemisphere has scientists asking: Has a predicted climate imbalance of the jet stream begun?
The Arctic is warming faster than other parts of the world, and scientists believe that is having a dramatic impact on the jet stream, which may be responsible for the unusual weather and stronger upper atmospheric winds of late.
On January 8, thousands of Britons were left without electricity in the aftermath of the most violent storms to hit the isles in more than a century. British Airways Flight 114 carried by strong winds journeyed from New York to London in a record five hours and 16 minutes.
Several jetliners flying from Europe to North America in recent weeks faced powerful headwinds, which forced them to make unscheduled mid-flight stops to refuel.
The jet stream – a narrow, variable band of westerly air currents miles above the Earth – is strongest in winter, when boundaries between hot tropical and cold polar air masses are most pronounced.
Currents can be even more turbulent at high altitudes flown in by jetliners some 10 kilometres above the Earth, where winds can reach 300 kilometres per hour.
Since 2012, researcher Jennifer Francis of Rutgers University in New Jersey has been trying to develop new scientific tools to study these “very messy” changes in the jet stream.
“Last winter and this winter the jet stream has been unusually strong,” she told the Royal Society of Britain last year, adding that scientists expect more of the same in coming years.
But not every expert feels the same way.
Climate expert James Screen of the University of Exeter, who recently co-authored an as-yet unpublished paper on the impact of Arctic warming on the jet stream, is sceptical of any direct link between the dramatic retreat of Arctic sea ice and more turbulent air travel.
“I have not seen any evidence to suggest a trend in the speed of the jet stream over the past few decades,” he said in an email.
He added, however: “That is not to say that climate change may not impact the jet stream in the future.”
