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.

PROMOTED VIDEO
Sport
Ojo Onaolapo celebrates winning the bronze medal
commonwealth games
Arts and Entertainment
Rock band Led Zeppelin in the early 1970s
musicLed Zeppelin to release alternative Stairway To Heaven after 43 years
News
i100
News
Prince Harry is clearing enjoying the Commonwealth Games judging by this photo
people(a real one this time)
Extras
indybest
News
Richard Norris in GQ
mediaGQ features photo shoot with man who underwent full face transplant
Sport
Lionel Messi looks on at the end of the final
football
News
ebookA unique anthology of reporting and analysis of a crucial period of history
News
Gardai wait for the naked man, who had gone for a skinny dip in Belfast Lough
newsTwo skinny dippers threatened with inclusion on sex offenders’ register as naturists criminalised
News
Your picture is everything in the shallow world of online dating
i100
News
The Swiss Re tower or 'Gherkin' was at one time the UK’s most expensive office when German bank IVG and private equity firm Evans Randall bought it
news
Life and Style
Attractive women on the Internet: not a myth
techOkCupid boasts about Facebook-style experiments on users
Sport
Van Gaal said that his challenge in taking over Bobby Robson's Barcelona team in 1993 has been easier than the task of resurrecting the current United side
football
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
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

Accounts Receivable / Accounts Payable Assistant - Central Lond

£27000 - £30000 per annum: Ashdown Group: Accounts Receivable / Accounts Payab...

Account Manager, Spanish, London Bridge

£30,000 + 20K Commssion: Charter Selection: This rapidly expanding organisatio...

.Net/ C# Developer/ Analyst Programmer - West London

£45000 - £50000 per annum + competitive: Progressive Recruitment: .NET/ C# .Pr...

Account Manager, Spanish, London Bridge

£30,000 + 20K Commssion: Charter Selection: This rapidly expanding organisatio...

Day In a Page

The children were playing in the street with toy guns. The air strikes were tragically real

The air strikes were tragically real

The children were playing in the street with toy guns
Boozy, ignorant, intolerant, but very polite – The British, as others see us

Britain as others see us

Boozy, ignorant, intolerant, but very polite
Countries that don’t survey their tigers risk losing them altogether

Countries that don’t survey their tigers risk losing them

Jonathon Porritt sounds the alarm
How did our legends really begin?

How did our legends really begin?

Applying the theory of evolution to the world's many mythologies
Watch out: Lambrusco is back on the menu

Lambrusco is back on the menu

Naff Seventies corner-shop staple is this year's Aperol Spritz
A new Russian revolution: Cracks start to appear in Putin’s Kremlin power bloc

A new Russian revolution

Cracks start to appear in Putin’s Kremlin power bloc
Eugene de Kock: Apartheid’s sadistic killer that his country cannot forgive

Apartheid’s sadistic killer that his country cannot forgive

The debate rages in South Africa over whether Eugene de Kock should ever be released from jail
Standing my ground: If sitting is bad for your health, what happens when you stay on your feet for a whole month?

Standing my ground

If sitting is bad for your health, what happens when you stay on your feet for a whole month?
Commonwealth Games 2014: Dai Greene prays for chance to rebuild after injury agony

Greene prays for chance to rebuild after injury agony

Welsh hurdler was World, European and Commonwealth champion, but then the injuries crept in
Israel-Gaza conflict: Secret report helps Israelis to hide facts

Patrick Cockburn: Secret report helps Israel to hide facts

The slickness of Israel's spokesmen is rooted in directions set down by pollster Frank Luntz
The man who dared to go on holiday

The man who dared to go on holiday

New York's mayor has taken a vacation - in a nation that has still to enforce paid leave, it caused quite a stir, reports Rupert Cornwell
Best comedians: How the professionals go about their funny business, from Sarah Millican to Marcus Brigstocke

Best comedians: How the professionals go about their funny business

For all those wanting to know how stand-ups keep standing, here are some of the best moments
The Guest List 2014: Forget the Man Booker longlist, Literary Editor Katy Guest offers her alternative picks

The Guest List 2014

Forget the Man Booker longlist, Literary Editor Katy Guest offers her alternative picks
Jokes on Hollywood: 'With comedy film audiences shrinking, it’s time to move on'

Jokes on Hollywood

With comedy film audiences shrinking, it’s time to move on