Antarctic ozone hole 'creating rainfall in subtropical region'

 

A A A

The ozone "hole" over Antarctica could be increasing the amount of rainfall as far away as the subtropical regions of the southern hemisphere, according to a study that highlights the global nature of climate changes.

For the first time scientists have found evidence to suggest the depletion of the thin ozone layer high above the South Pole can alter the wind patterns thousands of miles away that bring rain to the subtropics.

The researchers believe the thinning of the ozone layer in the polar stratosphere over the past few decades as a result of the build-up of man-made pollutants has caused a southern shift of the westerly jet stream, which has caused a corresponding migration of the climatic bands that result in dry or wet conditions south of the equator.

"The ozone hole is over Antarctica but it causes a moisturising trend over subtropical regions of the world, such as eastern Australia," said Sarah Kang of Columbia University in New York, who led the study published in Science.

"Previous work has shown the impact of the ozone hole on the circulating winds at higher latitudes nearer the poles, but this is the first work to link the thinning of the ozone layer with circulation patterns at lower latitudes nearer the equator," she said.

The ozone layer in the stratosphere shields the Earth from damaging ultraviolet radiation from the Sun. In the 1980s scientists found that over the South Pole the layer was thinning significantly as a result of the use of industrial chemicals, notably chlorofluorocarbons (CFCs) used as aerosols and refrigerants.

An 1989 international treaty banned CFCs but scientists believe it will take many decades before the ozone layer recovers completely. Nevertheless, Dr Kang and her colleagues believe rainfall changes in subtropical regions of the southern hemisphere between 1979 and 2000 can be explained, at least in part, by changes to the ozone layer.

The study, which used computerised climate modelling, suggested the circumpolar winds that swirl around the Antarctic continent have become more intense because of a cooling effect in the atmosphere above the South Pole caused by a thinner ozone layer.

"The ozone hole causes cooling in the stratosphere over the Antarctic and that cooling creates a larger temperature gradient, which causes the higher latitude circulating winds to shift further southward," Dr Kang said. "It's amazing the ozone hole, located so high up in the atmosphere over Antarctica can have an impact all the way to the tropics and affect rainfall there. It's just like a domino effect."

An implication of the finding is that scientists working for the Intergovernmental Panel on Climate Change (IPCC) will have to consider the impact of the ozone hole when they assess the man-made influence on the global climate, said Professor Lorenzo Polvani of the Lamont-Doherty Earth Observatory, who worked on the study.

"The ozone hole is not even mentioned in the summary for policymakers issued with the last IPCC report. We show in this study [it] has large and far-reaching impacts. The ozone hole is a big player in the climate system," Professor Polvani said. "While the ozone hole has been considered a solved problem we're now finding it has caused a great deal of the climate change that's been observed," he said.

Voices
The Sumatran tiger, endemic to the Indonesian island of Sumatra, is an endangered species
voicesJonathon Porritt: The wild tiger population is thought to have dropped by 97 per cent since 1900
Arts and Entertainment
Beast would strip to his underpants and take to the stage with a slogan scrawled on his bare chest whilst fans shouted “you fat bastard” at him
musicIndie music promoter was was a feature at Carter gigs
News
news
Arts and Entertainment
Story line: Susanoo slays the Yamata no Orochi serpent in the Japanese version of a myth dating back 40,000 years
arts + entsApplying the theory of evolution to the world's many mythologies
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
News
Performers dressed as Tunnocks chocolate teacakes, a renowned Scottish confectionary, perform during the opening ceremony of the 2014 Commonwealth Games at Celtic Park in Glasgow on July 23, 2014.
news
Life and Style
Popular plonk: Lambrusco is selling strong
Food + drinkNaff Seventies corner-shop staple is this year's Aperol Spritz
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
Shake down: Michelle and Barack Obama bump knuckles before an election night rally in Minnesota in 2008, the 'Washington Post' called it 'the fist bump heard round the world'
newsThe pound, a.k.a. the dap, greatly improves hygiene
Arts and Entertainment
La Roux
music
Arts and Entertainment
Graham Fellows as John Shuttleworth
comedySean O'Grady joins Graham Fellows down his local Spar
News
people
News
Ross Burden pictured in 2002
people
News
Elisabeth Murdoch: The 44-year-old said she felt a responsibility to 'stand up and be counted’'
media... says Rupert Murdoch
Arts and Entertainment
tv
Extras
indybest
Sport
Arsenal signing Calum Chambers
sportGunners complete £16m transfer of Southampton youngster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Junior / Graduate Application Support Engineer

£26000 per annum: Ashdown Group: A highly successful international media organ...

QA Manager - North Manchester - Nuclear & MOD - £40k+

£35000 - £41000 per annum + competitive: Progressive Recruitment: QA Manager -...

Property Finance Partner

Very Competitive Salary: Austen Lloyd: LONDON - BANKING / PROPERTY FINANCE - ...

Agile Tester

£28000 - £30000 per annum + competitive: Progressive Recruitment: An ambitious...

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