UK Storms Caused By Slow/Fast Jet Stream (Delete as appropriate)

By Paul Homewood

 

A lorry overturned on the M74

 

According to the BBC, yesterday’s storms in Scotland, and to a lesser extent the rest of Britain, have been triggered by a very strong jet stream:

 

The Met Office’s chief forecaster said a depression had been developing over the Atlantic in association with a very strong jet stream. It is said to have been triggered by sub-zero temperatures in the US hitting warmer air.

 

This is no secret, as the Guardian warned us earlier in the week:

 

Britain is braced for a night of gale-force winds stirred up by a 250mph jet stream, to be followed by snow…..

 

The ferocious gales have been whipped up by an extra-powerful jet stream triggered by plunging temperatures in the US hitting warmer air in the south. Forecasters said the 250mph jet stream would bring two vigorous depressions to the UK over the coming days.

 

This situation is in fact not dissimilar to last winter’s storms.

But weren’t we told by by “climate experts” that the opposite would occur? Queue No1 scamster, Dr Jennifer Francis:

 

 

http://www.newscientist.com/article/dn26278-crazy-weather-traced-to-arctics-impact-on-jet-stream.html#.VLA8O3vLL5z

 

The rapid retreat of Arctic sea ice caused by climate change may be to blame for more frequent prolonged spells of extreme weather in Europe, Asia and North America, such as heat waves, freezing temperatures or storms.

These are relatively short-term periods of bizarre weather, like the cold snap that paralysed North America earlier this year, rather than longer-term rises in temperature.

They are related to "stuck" weather patterns, Jennifer Francis of Rutgers University in New Brunswick, New Jersey, told a conference on Arctic sea ice reduction in London on 23 September. "Is it global warming? I think it’s safe to answer yes," she told the meeting.

Francis said a growing number of studies, including her own, suggest that the melting Arctic is having knock-on effects on the jet stream, the river of air that snakes around the northern hemisphere at an altitude of around 5 to 6 kilometres, and which has a profound impact on the world’s weather.

The jet stream is driven by the flow of air between the cold Arctic pole and warmer air that moves upwards from nearer the equator. As the warmer air advances polewards, it is swung eastwards by the Coriolis force which comes from Earth’s spin, creating a snake-like stream. "It’s a fast-moving river of air, a very messy creature," says Francis.

 

The strength of the jet stream depends on the temperature gradient between the regions of cold and warm air – the wider the difference, the faster and stronger the jet stream. 

The Arctic is warming twice as fast as the rest of the planet, an effect enhanced when the sea ice that normally cools the Arctic air melts away. Because of this, the air currents that come from that region are getting disproportionately warmer too, narrowing the temperature difference between the Arctic and southerly winds, and thereby weakening the jet stream itself. "The winds have weakened by 10 per cent over the past three decades in the west-to-east wind of the jet stream," says Francis.

Francis thinks that, as the cool air of the Arctic becomes warmer, the jet stream is slowing down, almost to the point of stopping trapping weather systems in one place for prolonged periods. Instead of swirling round the world, winds reverberate back and forth in the same place, creating what she calls "extreme waves".

Her research shows that these extreme waves are becoming much more common, helping to explain the increase in prolonged extreme weather events. Between 1995 and 2013 – the period when the Arctic began warming disproportionately fast – extreme waves over North America became 49 per cent more common during the North American summer and 41 per cent more common in the autumn than they were between 1979 and 1994, before the disproportionate Arctic warming.

http://www.newscientist.com/article/dn26278-crazy-weather-traced-to-arctics-impact-on-jet-stream.html#.VLA8O3vLL5z

 

Then, inevitably, we have Katharine Hayhoe, who understandably has books to sell, who jumps on on the bandwagon:

 

Remember the polar vortex, the huge mass of Arctic air that can plunge much of the U.S. into the deep freeze? You might have to get used to it.

A new study says that as the world gets warmer, parts of North America, Europe and Asia could see more frequent and stronger visits of that cold air. Researchers say that’s because of shrinking ice in the seas off Russia.

Normally, the polar vortex is penned in the Arctic. But at times it escapes and wanders south, bringing with it a bit of Arctic super chill.

That can happen for several reasons, and the new study suggests that one of them occurs when ice in northern seas shrinks, leaving more water uncovered.

Normally, sea ice keeps heat energy from escaping the ocean and entering the atmosphere. When there’s less ice, more energy gets into the atmosphere and weakens the jet stream, the high-altitude river of air that usually keeps Arctic air from wandering south, said study co-author Jin-Ho Yoon of the Pacific Northwest National Laboratory in Richland, Washington. So the cold air escapes instead.

That happened relatively infrequently in the 1990s, but since 2000 it has happened nearly every year, according to a study published Tuesday in the journal Nature Communications. A team of scientists from South Korea and United States found that many such cold outbreaks happened a few months after unusually low sea ice levels in the Barents and Kara seas, off Russia.

The study observed historical data and then conducted computer simulations. Both approaches showed the same strong link between shrinking sea ice and cold outbreaks, according to lead author Baek-Min Kim, a research scientist at the Korea Polar Research Institute. A large portion of sea ice melting is driven by man-made climate change from the burning of fossil fuels, Kim wrote in an email.

The study was praised by several other scientists who said it does more than show that sea ice melt affects worldwide weather, but demonstrates how it happens, with a specific mechanism.

Katharine Hayhoe, a Texas Tech climate scientist in Lubbock, said the study "provides important insight into the cascading nature of the effects human activities are having on the planet."

[This was despite the fact that she herself had previously and continually forecast that milder winters would result from global warming.

 

We have also had the Liar in Chief’s “Scientific Expert”, John Holdren, trying to persuade us about the same.

 

 

 

The reality is, of course, the opposite of what the scamsters would have us believe, as Hubert Lamb succinctly explained in his book, “Historic Storms of the North Sea”, which described why storms were far worse during the Little Ice Age:

 

“it is likely that the increased intensity of storms in the Little Ice Age had to do with the source of potential energy in the, at that time, enhanced thermal gradient between the colder ocean surface in the seas about Iceland and the ocean south of 50-55N and the Bay of Biscay.”

 

It appears that climatology is the only branch of science that has gone backwards in the 21stC.