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
Arts and Entertainment
Sheeran arrives at the 56th annual Grammy Awards earlier this year
musicYes, that would be Ed Sheeran, according to the BBC
Arts and Entertainment
AKB48 perform during one of their daily concerts at Tokyo’s Akihabara theatre
musicJapan's AKB48 are one of the world’s most-successful pop acts
News
Ian Thorpe has thanked his supporters after the athlete said in an interview that he is gay
people
News
The headstone of jazz great Miles Davis at Woodlawn Cemetery in New York
news
Arts and Entertainment
Brendan O'Carroll has brought out his female alter-ego Agnes Brown for Mrs Brown's Boys D'Movie
filmComedy holds its place at top of the UK box office
News
newsBear sweltering in zoo that reaches temperatures of 40 degrees
Arts and Entertainment
Professor Kathy Willis will showcase plants from the Royal Botanic Gardens at Kew
radioPlants: From Roots to Riches has been two years in the making
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Arts and Entertainment
TV The follow-up documentary that has got locals worried
Arts and Entertainment
Eminem's daughter Hailie has graduated from high school
music
Arts and Entertainment
Original Netflix series such as Orange Is The New Black are to benefit from a 'substantial' increase in investment
TVHoax announcement had caused outrage
Life and Style
Swimsuit, £245, by Agent Provocateur
fashion

Diving in at the deep end is no excuse for shirking the style stakes

News
One Direction star Harry Styles who says he has no plans to follow his pal Cara Delevingne down the catwalk.
peopleManagement confirms rumours singer is going it alone are false
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
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

Dynamics CRM Developer (C#, .NET, Dynamics CRM 2011/2013)

£40000 - £60000 per annum + Benefits + Bonus: Harrington Starr: Dynamics CRM D...

Web Developer (C#, ASP.NET, AJAX, JavaScript, MVC, HTML)

£40000 - £45000 per annum + Benefits + Bonus: Harrington Starr: Web Developer ...

C# R&D .NET Developer-Algorithms, WCF, WPF, Agile, ASP.NET,MVC

£50000 - £67000 per annum + Benefits + Bonus: Harrington Starr: C# R&D .NE...

C# Developer (Web, HTML5, CSS3, ASP.NET, JS, Visual Studios)

£40000 - £50000 per annum + Benefits + Bonus: Harrington Starr: C# Developer (...

Day In a Page

Super Mario crushes the Messi dream as Germany win the 2014 World Cup in Brazil

Super Mario crushes the Messi dream

Germany win the 2014 World Cup in Brazil
Saharan remains may be evidence of the first race war, 13,000 years ago

The first race war, 13,000 years ago?

Saharan remains may be evidence of oldest large-scale armed conflict
Scientists find early warning system for Alzheimer’s

Scientists find early warning system for Alzheimer’s

Researchers hope eye tests can spot ‘biomarkers’ of the disease
Sex, controversy and schoolgirl schtick

Meet Japan's AKB48

Pop, sex and schoolgirl schtick make for controversial success
Iraq crisis: How Saudi Arabia helped Isis take over the north of the country

How Saudi Arabia helped Isis take over northern Iraq

A speech by an ex-MI6 boss hints at a plan going back over a decade. In some areas, being Shia is akin to being a Jew in Nazi Germany, says Patrick Cockburn
The evolution of Andy Serkis: First Gollum, then King Kong - now the actor is swinging through the trees in Dawn of the Planet of the Apes

The evolution of Andy Serkis

First Gollum, then King Kong - now the actor is swinging through the trees in Dawn of the Planet of the Apes
You thought 'Benefits Street' was controversial: Follow-up documentary 'Immigrant Street' has got locals worried

You thought 'Benefits Street' was controversial...

Follow-up documentary 'Immigrant Street' has got locals worried
Refugee children from Central America let down by Washington's high ideals

Refugee children let down by Washington's high ideals

Democrats and Republicans refuse to set aside their differences to cope with the influx of desperate Central Americas, says Rupert Cornwell
Children's books are too white, says Laureate

Children's books are too white, says Laureate

Malorie Blackman appeals for a better ethnic mix of authors and characters and the illustrator Quentin Blake comes to the rescue
Blackest is the new black: Scientists have developed a material so dark that you can't see it...

Blackest is the new black

Scientists have developed a material so dark that you can't see it...
Matthew Barzun: America's diplomatic dude

Matthew Barzun: America's diplomatic dude

The US Ambassador to London holds 'jeans and beer' gigs at his official residence – it's all part of the job, he tells Chris Green
Meet the Quantified Selfers: From heart rates to happiness, there is little this fast-growing, self-tracking community won't monitor

Meet the 'Quantified Selfers'

From heart rates to happiness, there is little this fast-growing, self-tracking community won't monitor
Madani Younis: Five-star reviews are just the opening act for British theatre's first non-white artistic director

Five-star reviews are just the opening act for British theatre's first non-white artistic director

Madani Younis wants the neighbourhood to follow his work as closely as his audiences do
Mrs Brown and her boys: are they having a laugh?

Mrs Brown and her boys: are they having a laugh?

When it comes to national stereotyping, the Irish – among others – know it can pay to play up to outsiders' expectations, says DJ Taylor