UK weather: High anxiety among jet stream watchers

 

It travels around the world at up to 200mph, at altitudes of between five and seven miles. It controls Britain's weather and can make or break a summer holiday. But something is happening to the jet stream that could explain why Britain has experienced a conveyor belt of storms dumping huge amounts of rain onto flood-battered parts of the country.

Scientists are increasingly convinced that the jet stream is stuck in a position that has thrown warm, moisture-laden air from the Atlantic over Britain for weeks at a time. Some climate researchers believe it is affected by warmer-than-usual conditions in the Arctic. The result is that the ribbon of air is blocked in a "standing wave", causing temperatures to plunge in the US and storms to wreak havoc in the UK.

"The jet stream is what generates our weather, steers our weather... it basically controls the weather all around the mid-latitude areas except the tropics," Professor Jennifer Francis of Rutgers University in Brunswick, New Jersey, told the American Association for the Advancement of Science.

"It's been in a very persistent pattern shooting pretty straight across the Atlantic bringing a lot of moisture, a lot of energy and a lot of storms directly into the UK."

The jet stream flows from west to east around the northern hemisphere and is driven by the temperature difference between intensely cold Arctic air and relatively warmer air at lower latitudes. But when this temperature difference is less marked, the jet stream becomes slower and tends to wander off course, Professor Francis explained.

"The temperature difference between the Arctic and lower latitudes is one of the main sources of fuel for the jet stream. It's what drives the winds, and because the Arctic is warming so fast, that temperature difference is getting smaller, and so the fuel for the jet stream is getting weaker," she said. "When it gets into this pattern those big waves tend to stay in the same place for some time. The pattern we've seen in December and January has been one of these very wavy patterns.

"It doesn't mean that every year the UK is going to be in a stormy pattern," Professor Francis added. "Next year you could have very dry conditions, and for that to be persistent." What was unusual, she said, was the persistence of a pattern for a long time.

"You can't say that flooding is going to happen more often. Next year may be dry, but whatever you get is going to last longer."

Britain is not the only place to feel this effect. Alaska this winter has experienced some of the warmest temperatures on record and, for the first time, rain rather than snow has fallen on the northern slopes of the Alaskan mountains in December, she said.

At the same time, the jet stream has dipped southwards over California, causing a blocking effect that has prevented storms from moving in from the Pacific. The result is a severe winter drought, Professor Francis explained.

"It's consistent with our hypothesis about what's been happening over the past couple of decades with the Arctic warming so rapidly," she said.

Temperature records show that the Arctic is one of the fastest warming regions on Earth, experiencing average temperature increases of more than 4C over the past 30 years. The volume of sea ice in the Arctic is currently at one of the lowest levels ever for this time of year. Although several factors can affect the jet stream, the only one that appears to be changing dramatically is the temperature difference between the Arctic and more southerly latitudes. The observations fit in with the computer predictions of what can happen to the jet stream, Professor Francis said.

"I can't say at this point that it is the most likely explanation. It's still such a brand new line of research. I think it's certainly one of the most likely explanations," she said.

Start your day with The Independent, sign up for daily news emails
News
news
News
peopleIt seems you can't silence Katie Hopkins, even on Christmas Day...
Arts and Entertainment
tvChristmas special reviewed
Arts and Entertainment
Wolf (Nathan McMullen), Ian (Dan Starky), The Doctor (Peter Capaldi), Clara (Jenna Coleman), Santa Claus (Nick Frost) in the Doctor Who Christmas Special (BBC/Photographer: David Venni)
tvOur review of the Doctor Who Christmas Special
PROMOTED VIDEO
News
i100
Arts and Entertainment
Jenna Coleman as Clara Oswald in the Doctor Who Christmas special
tvForget the rumours that Clara Oswald would be quitting the Tardis
Arts and Entertainment
Japanese artist Megumi Igarashi showing a small mascot shaped like a vagina
art
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Life and Style
fashion
Arts and Entertainment
Left to right: Stanley Tucci, Sophie Grabol and Christopher Eccleston in ‘Fortitude’
tvSo Sky Atlantic arrived in Iceland to film their new and supposedly snow-bound series 'Fortitude'...
Arts and Entertainment
tv
News
The Queen delivers her Christmas message
newsTwitter reacts to Her Majesty's Christmas Message
Sport
sport
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Ashdown Group: Senior Marketing Executive- City of London, Old Street

£40000 - £43000 per annum + benefits: Ashdown Group: Senior Marketing Executiv...

Ashdown Group: Marketing Manager

£40000 - £43000 per annum + benefits: Ashdown Group: An international organisa...

Ashdown Group: Internal Recruiter -Rugby, Warwickshire

£25000 - £30000 per annum: Ashdown Group: Internal Recruiter -Rugby, Warwicksh...

Ashdown Group: Marketing Manager/Marketing Controller (Financial Services)

£70000 - £75000 per annum + benefits: Ashdown Group: Marketing Manager/Marketi...

Day In a Page

A Christmas without hope: Fears grow in Gaza that the conflict with Israel will soon reignite

Christmas without hope

Gaza fears grow that conflict with Israel will soon reignite
After 150 years, you can finally visit the grisliest museum in the country

The 'Black Museum'

After 150 years, you can finally visit Britain's grisliest museum
No ho-ho-hos with Nick Frost's badass Santa

No ho-ho-hos with Nick Frost's badass Santa

Doctor Who Christmas Special TV review
Chilly Christmas: Swimmers take festive dip for charity

Chilly Christmas

Swimmers dive into freezing British waters for charity
Veterans' hostel 'overwhelmed by kindness' for festive dinner

Homeless Veterans appeal

In 2010, Sgt Gary Jamieson stepped on an IED in Afghanistan and lost his legs and an arm. He reveals what, and who, helped him to make a remarkable recovery
Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

Yazidi girls killing themselves to escape rape and imprisonment
Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

Ed Balls interview

'If I think about the deficit when I'm playing the piano, it all goes wrong'
He's behind you, dude!

US stars in UK panto

From David Hasselhoff to Jerry Hall
Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

Grace Dent's Christmas Quiz

What are you – a festive curmudgeon or top of the tree?
Nasa planning to build cloud cities in airships above Venus

Nasa planning to build cloud cities in airships above Venus

Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect
Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

Clocks, rifles, swords, frogmen’s uniforms

Surrounded by high-rise flats is a little house filled with Lebanon’s history
Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

Four months after the bombardment, Gaza’s wounds are yet to heal

Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
Gastric surgery: Is it really the answer to the UK's obesity epidemic?

Is gastric surgery really the answer to the UK's obesity epidemic?

Critics argue that it’s crazy to operate on healthy people just to stop them eating
Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

Homeless Veterans appeal: Christmas charity auction

Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
Pantomime rings the changes to welcome autistic theatre-goers

Autism-friendly theatre

Pantomime leads the pack in quest to welcome all