Flights to get bumpier as turbulence to double

Flying is to become a far less comfortable experience according to a study of how levels of turbulence are set to change over the next 40 years. Trans Atlantic flights will encounter up to twice as much turbulence while enroute, the research has shown.

Using atmospheric computer models, the scientists behind the work were able to simulate how changes in the climate will impact on the invisible patches of mixing air that cause turbulence.

Dr Paul Williams, a Royal Society research fellow at the University of Reading, said the results suggest air passengers will have less comfortable journeys in the future.

It could also have far more serious implications than a few more spilt drinks and more time staring at the illuminated seat belt sign.

"Turbulence injures hundreds of passengers and crew every year," said Dr Williams. "The total cost to society is about £100 million globally each year.

Trans Atlantic flights will encounter up to twice as much turbulence while enroute, the research has shown.

Using atmospheric computer models, the scientists behind the work were able to simulate how changes in the climate will impact on the invisible patches of mixing air that cause turbulence.

Dr Paul Williams, a Royal Society research fellow at the University of Reading, said the results suggest air passengers will have less comfortable journeys in the future.

It could also have far more serious implications than a few more spilt drinks and more time staring at the illuminated seat belt sign.

"Turbulence injures hundreds of passengers and crew every year," said Dr Williams. "The total cost to society is about £100 million globally each year.

"Planes are designed to withstand this kind of turbulence, but if they suffer any damage it will disrupt flights.

"The main impact will be that flights will become less comfortable and the seat belt sign will need to be on twice as much as it currently is."

Dr Williams and Dr Manoj Joshi from the University of East Anglia, analysed supercomputer simulations of the atmospheric jet stream over the North Atlantic Ocean.

The study, which is published in the journal Nature Climate Change, showed that by the middle of this century, the amount of airspace containing significant clear air turblence is most likely to double.

The average strength of the turbulence will also increase by between 10 per cent and 40 per cent.

The aviation industry is often blamed for contributing to climate change, but the new study has shown that it will also be affected by any changes that take place in the atmosphere.

Dr Williams said: "Thirty thousand feet above our heads, the jet stream is being accelerated, which is having a destabilising effect that is making air turbulence more likely to form.

"There are 600 transatlantic crossings every day, so a lot of fights will be affected by this." More

 

Jet stream changes take rap for Britain's icy weather Save

Britain's weather is excelling itself.

It produced an Easter Sunday that was the coldest on record in the UK.

Temperatures stuck below zero in many regions, freezing conditions continued to disrupt transport and experts warned of increasing threats to animals and birds already struggling to survive loss of habitat and climate change.

The start of British Summer Time was marked in Braemar, Scotland, by temperatures that fell to minus 11C. For good measure, an unappetising April for the UK looks likely to follow.

The persistence of the northern spring's grim weather is striking, for it comes after a series of other extreme meteorological events in recent years. Last winter, a severe drought triggered stern warnings by the UK's Environment Agency that water rationing and hosepipe bans would soon have to be introduced - until several months of torrential rain produced widespread flooding.

Britain's weather is now fluctuating on a grand scale.

"There is no doubt that the recent weather has been highly changeable - on both sides of the Atlantic," said meteorologist Nicholas Klingaman, of Reading University.

The problem lies with the jet stream, a narrow band of strong winds that sweep around the planet between the tropics and the Arctic.

"Its behaviour has changed dramatically in the past few years and has produced these lengthy bouts of extreme weather.

"The real question, of course, is an obvious one: why has the jet stream changed its behaviour?"

The jet stream gets its name because it circulates at an altitude of around 10km to 15km, the height at which most jets fly. It runs from west to east, which can give aircraft significant boosts on eastbound flights across the Atlantic and Pacific.

However, this giant river of air has begun to meander and to slow down, trapping regions of high or low pressure over the same part of the globe, including the freezing air that has hung over Britain for the past six weeks. As to the reason for this change, more meteorologists point to global warming. In particular, they pinpoint the warming of the Arctic as the most likely culprit for the destabilising weather patterns.

"The Arctic is warming faster than any other place on Earth," said meteorologist Jennifer Francis, of Rutgers University, New Jersey.

"Arctic temperatures have increased at more than twice the global rate. You can see this in the sea ice in summer there. In just the three decades, it has declined by 40 per cent. More to the point, that warming is now changing weather patterns across the Northern Hemisphere."

How the warming of the Arctic affects our weather has much to do with the origins of the jet stream.

Air in the tropics is warmer than the Arctic and it rises. As a result, the atmosphere there is higher than it is over the Arctic. "A gradient is created and air slides down this atmospheric hill towards the Arctic," said Francis.

"This flow of air, high up in the atmosphere, from the tropics to the Arctic, is the crucial ingredient in the creation of the jet stream.

"The world rotates from west to east, however, and that rotation whips up this northward flow of air that descends over higher latitudes and sends it flying east round the globe as the jet stream.

"Earth rotates from west to east and that is what drives the jet stream in the same direction."

Until recently, this air flew around the planet in a slightly wavy path, between 30 and 60 degrees north.

"The trouble is that the gradient between the atmosphere in the lower latitudes and in the Arctic is being disrupted by global warming," said Francis. "It is becoming less of a stream and is behaving more like a sluggish estuary that is meandering across the upper atmosphere at middle latitudes." More

 

Killer Heat Waves and Floods Linked to Climate Change

UXBRIDGE, Canada, Feb 27 2013 (IPS) - Killer heat waves, floods and storms are increasingly caused by climate change, new research reveals.

Scientists in Germany say they have found how greenhouse gases from burning fossil fuels are helping to trap the jet stream, resulting in extraordinary weather such as the 2010 Pakistan flood and the 2011 heat wave in the United States.

Human-driven climate change repeatedly disturbs the flow of atmospheric waves around the globe’s Northern hemisphere, said lead author Vladimir Petoukhov of the Potsdam Institute for Climate Impact Research (PIK) in Germany.

Giant atmospheric waves called Rossby waves are meanders in the strong, high-altitude winds known as jet streams and have a major influence on weather. These wave movements are caused by the difference in temperatures between the cold air from the Arctic and hot air from the tropics.

When the waves shift north, they suck warm air from the tropics to Europe, Russia, or the U.S., and when they swing down, they do the same thing with cold air from the Arctic, said Petoukhov.

“During several recent extreme weather events, these planetary waves almost freeze in their tracks for weeks,” he said. “So instead of bringing in cool air after having brought warm air in before, the heat just stays.”

This unnatural pattern is due to human heating of the climate through emissions of greenhouse gases that result from burning fossil fuels, according to the study published this week in Proceedings of the National Academy of Sciences.

However, this heating of the atmosphere is wildly uneven. The Arctic is warming two to three times faster than the global temperature rise of 0.8C and that affects the Rossby waves and is slowing the jet stream.

“(Our research) complements previous research that already linked such phenomena to climate change,” said Hans Joachim Schellnhuber, a co-author of the study.

IPS previously reported research showing the dramatic loss of Arctic sea ice and rapid warming of the region was affecting weather patterns in the northern hemisphere.

The unprecedented expanse of ice-free Arctic Ocean has been absorbing the 24-hour sun over the short polar summer. The heat in the water must be released into the atmosphere if the ice is to re-form in the autumn.

“This is like a new energy source for the atmosphere,” Jennifer Francis, a researcher at Rutgers University, told the Guardian.

Major declines of Arctic summer sea ice as in 2011 and 2007 have been linked to colder winters in the UK and northern Europe, Francis said. The record ice loss in 2012 has been followed by a cold and stormy winter over much of Europe.

“The jet stream is clearly weaker,” said Francis. That means weather systems, be it rain or dry conditions, are slow to move on and last longer. Ultimately, this can result in “blocking” events, such as the conditions that produced the terrible heatwave in western Russia during the summer of 2010 and floods in Pakistan, she said.

Last summer, Greenland experienced a similar blocking anti-cyclone, resulting in a record surface melting of its ice sheet. “Blocks act like a traffic jam, slowing down weather patterns elsewhere,” Francis said.

Scientists are surprised by how extreme these changes have been with a relatively small amount of warming. That has prompted some to speak out politically to urge emission reductions. On Monday, a group of Canadian and U.S. scientists pleaded with the Canadian government to stop the expansion of the Alberta tar sands oil projects and take real steps to reduce carbon emissions. More