Like this one:
![britainAR[1]](http://wattsupwiththat.files.wordpress.com/2013/07/britainar1.png)
Image from NOAA ESRL
From the Institute of Physics
Atmospheric rivers set to increase UK winter flooding
The prolonged heat wave that has bathed the UK in sunshine over the past month has given the country an unexpected taste of summer that has seemed to be missing in recent years.
However, a new study published today, 24 July, in IOP Publishing’s Environmental Research Letters, has provided warnings that will chime with those accustomed to more typical British weather.
According to the study, winter flooding in the UK is set to get more severe and more frequent under the influence of climate change as a result of a change in the characteristics of atmospheric rivers (ARs).
ARs are narrow regions of intense moisture flows in the lower troposphere of the atmosphere that deliver sustained and heavy rainfall to mid-latitude regions such as the UK.
They are responsible for many of the largest winter floods in the mid-latitudes and can carry extremely large amounts of water: the AR responsible for flooding in the northwest of the UK in 2009 transported 4500 times more water than the average flow in the River Thames in London.
The researchers, from the University of Reading and University of Iowa, found that large parts of the projected changes in AR frequency and intensity would be down to thermodynamic changes in the atmosphere, rather than the natural variability of the climate, suggesting that it is a response to anthropogenic climate change.
To reach these conclusions, the researchers used simulations from five state-of-the-art climate models to investigate how the characteristics of ARs may change under future climate change scenarios.
Firstly, they used the climate models to see how accurately they could simulate the ARs that occurred between 1980 and 2005. The five models did this successfully and were deemed capable of projecting how future ARs will develop under different scenarios.
The models were then used to simulate future conditions under two scenarios – RCP4.5 and RCP8.5 – that represent different, yet equally plausible, scenarios for future increases in greenhouse gas concentrations in the atmosphere. They projected changes that would occur between 2074 and 2099.
Each of the five models simulated an increase in AR frequency. For the RCP8.5 projections, which represents stronger increases in greenhouse gas concentrations than RCP4.5, there was a striking level of consistency in the magnitude of change in AR frequency – all models showed an approximate doubling of the number of future ARs compared to the simulations for 1980 – 2005.
The models also projected an increase in intensity of the ARs, meaning an AR impacting the UK in the future is projected to deliver more moisture, potentially causing larger precipitation totals.
Lead author of the research, Dr David Lavers, said: “ARs could become stronger in terms of their moisture transport. In a warming world, atmospheric water vapour content is expected to rise due to an increase in saturation water vapour pressure with air temperature. This is likely to result in increased water vapour transport.
“The link between ARs and flooding is already well established, so an increase in AR frequency is likely to lead an increased number of heavy winter rainfall events and floods. More intense ARs are likely to lead to higher rainfall totals, and thus larger flood events.”
From Wednesday 24 July, this paper can be downloaded from http://iopscience.iop.org/1748-9326/8/3/034010/article
omnologos: thanks for the discussion of the MET. You had my wife rolling with laughter
According to the study, winter flooding in the UK is set to get more severe and more frequent under the influence of climate change as a result of a change in the characteristics of atmospheric rivers (ARs).
This part raised my eyebrows, but I decided to give them the benefit of the doubt, and continued reading. I figured maybe the basis for the forecasts are actual observations of ARs.
To reach these conclusions, the researchers used simulations from five state-of-the-art climate models,/b> to investigate how the characteristics of ARs may change under future climate change scenarios.
I stopped reading at this point since they’re talking about Worlds of Make-Believe.
NOAA, that bastion of indelible facts, has a very interesting web site dedicated to AR study that is worth a read. But follow the axiom that that which is not BS can be educational. ARs are not the jet stream, for example, and ARs are verifiable. Somewhere is an animated all-world view of ARs and if you watch it several times it validates Willis’ tropical heat engine ideas. And it supports an idea of mine that tremendous amounts of energy are pumped out of the tropics as water vapor.
http://www.esrl.noaa.gov/psd/atmrivers/
Yet another “dry lab”, devoid of any experiment or observation.
All the CMIP5 models were tuned in some way, almost certainly including to the TOA radiation flux, adjusting various parameters (aerosol forcing, e.g.) within some bounds until they got a statistically “skilled” hindcast. Then they were used to project the future.
Of course, there’s no way to know whether the tuned models actually got the underlying climate dynamics correct. That’s just assumed because, after all, the models got that lovely statistical hindcast.
Statistically skillful hindcast + incorrect dynamics = nonsensical non-physical forecast. That’s climate modeling today. But it gets headlines, and everyone has the deep satisfaction of making earth-shaking pronouncements. Who needs the Sibyls when oracular climate modelers abound?
lol Guess we’d better brace ourselves then.
Of course, when any flooding does arrive the BBC will take their cameras to the nearest location where houses have been built on a floodplain, and then blame it all on global warming. Dipsticks.
So, with simulations from five state-of-the-art climate models and much fiddling of the data, the Met has managed to predict the past
Models: Actually having used computer models for engineering design, project management, financial management, tax planning, financial planning and human resource management and other things since the 60’s, I have great faith in computer models. But they have to produce useable, testable, and verifiable results. Otherwise they are just wasting time and electricity. AR’s are real. In western North America we have all heard of the “Pinapple Express”. It’s worth developing forecasting models. But for some reason I am thinking one, two, five, and ten year time horizons that can be measured/verified would be a lot more useful than looking at something that will occur long after most of us are dead.
Or maybe that’s the point?
“To reach these conclusions, the researchers used simulations from five state-of-the-art climate models to investigate how the characteristics of ARs may change under future climate change scenarios.
Firstly, they used the climate models to see how accurately they could simulate the ARs that occurred between 1980 and 2005. The five models did this successfully and were deemed capable of projecting how future ARs will develop under different scenarios.”
Is that like “Pull my finger”?
Probably a Scam to enable the Insurance companies to offload All flood coverage onto the new scheme proposed by the Government, Who will argue about it, it has academic backing 🙂
“…To reach these conclusions, the researchers used simulations from five state-of-the-art climate models to investigate how the characteristics of ARs may change under future climate change scenarios….”
But first they tested all the climate models to find five that did what they wanted.
tom konerman says: “The UK put a boat out to sea in 1912 and proclaimed it to be unsinkable.”
Pshhh! It is now.
I see the UK branch of the Phil Pockets Institute has been going into overdrive again…
Luckily the Brits are now going to enjoy dry winter weather until the Met Office next predict dry winter weather. This could be built into a Larson of the Far Side cartoon.
This is right out of De. Seuss: “Ooblek, ooblek is our cry! More than that we know not why”. Courtessy “Bartholomew and the Oobleck”, a 1949 book by Dr. Seuss. Why aren’t these people ashamed of themselves? I guess grant dollars assuage a lot of grief.
Sorry UK guys, that ship was a technology disaster and bad judgment but Piltdown man was just the same kind of fraud 🙂 Mea Culpa, we in the Netherlands have recently had our Diederik Stapel affair, that was a big hit too 🙂
And while they’re patting themselves on the back, hearing the cheers of their co-modelers, collecting awards and signing up for grants, they are immune to the gales of laughter at their ridiculous claims.
Oh no, we the unbelieving wicked will see, oh yes we shall see, when it comes to pass, yea verily.
Meanwhile, I highly recommend examining the entrails of a sacrificed goat for a more accurate picture of the future.
Yes, this “study” is a load of crap. The very concept of forecasting such trends in any credible manner is ridiculous.
Firstly, they used the climate models to see how accurately they could simulate the ARs that occurred between 1980 and 2005.
Entirely based on models? The ones that can’t get anything else right and they don’t know why? Strike 1.
What happened to the data since 2005? No mention of getting things right after the hindcast period? Did we lose the data from 2006 on? What is the excuse for not comparing to actual data for the following 7 years? Strike 2.
Predictions so far out that they cannot be verified except by people who for the most part aren’t even born yet? Strike 3.
Wanna know the funny part? No one is even throwing balls at them! They are swinging at empty air, hoping nobody will notice.
“……the researchers used simulations from five state-of-the-art climate models……” They’ll come on in the same old way and Mother Nature will see them off in the same old way. It seems to me that GCM’s are the modern version of the philosopher’s stone – and sought after for much the same reasons. What was it that Einstein said about insanity?
They sound very like schoolchildren building fantasies from ignorance.
Streams of enhanced humidity are a routine occurrence in the approaches to Western Europe and result from humid air being drawn up from the tropics on the southern side of the jet stream.
When the globe is warming the streams of humidity move poleward and when it is cooling they shift equatorward.
Larger deposits of rainfall tend to occur when the globe is cooling because it is then that more frequent high pressure blocking cells tend to keep the flows static for longer periods of time.
Total global humidity doesn’t seem to be changing significantly.
This is just alarmist hype.
Atmospheric rivers and floods have been covered here at WUWT before although I could not find the post. This was when the USGS came out with the ArkStorm Scenario:
http://pubs.usgs.gov/of/2010/1312/
The hypothetical storm depicted here would strike the U.S. West Coast and be similar to the intense California winter storms of 1861 and 1862 that left the central valley of California impassible.
Wiki has an entry on the storm:
http://en.wikipedia.org/wiki/Great_Flood_of_1862
They say this:
“We show that North Atlantic ARs are projected to become stronger and more numerous in the future scenarios of multiple simulations from five state-of-the-art global climate models (GCMs) ”
which is just a recycling of the earlier proposition that AGW will result in a stronger zonal (west to east) flow of air in the middle latitudes. Previously AGW theory associated the faster more zonal flow with more poleward jets which would have put the flow more often north of the UK, hence the past expectations of a hotter, drier Mediterranean type climate in the UK.
In reality, since 2000 the flows have become more meridional and have sunk equatorward which is the opposite of the earlier expectation but which has caused more cool air and rainfall over the UK in summer and colder drier winters rather than their suggestion of wetter winters.
Their proposals have already been proved incorrect by real world events since 2000.
John F Hultquist:
http://wattsupwiththat.com/2011/02/12/atmospheric-rivers-key-to-extratropical-water-vapor-transport/
Why not 2014 to 2039?
That would be initially testable within the working lives of the researchers.
Don’t they want to know if they are right?
There’s a huge problem with their conclusion that it’s the result of man made global warming.
The climate has not warmed in 17 years, therefore if it’s temperature-related we should have experienced the same AR effects throughout this period. We haven’t, therefore it’s natural variability.
I do wish academics would look at history before making their pronouncements.
The UK is currently in a highly benign climatic period. The weather was FAR worse prior to 1850 and more especially in the LIA periods
1228 inundations of rivers in Dec Jan and Feb –in Worcester- such that no one then living had ever seen the like in their time
1229 severe winter ‘unusually bitter, waters so frozen horsemen could cross upon the ice, great snow afterwards earth covered for several days.’
1231 March to October hardly any rain anywhere in England-great drought
1233 wet summer from 23 March with great inundations of rain through the whole summer destroying warrens and washed away the ponds and mills throughout almost all England. Water formed into lakes in middle of the crops where the fishes of the rivers were seen to great astonishment and mills were standing in various places they had never before been seen.
1233-1234 severe frost from Christmas 1233 to Feb 2 1234 destroying roots of trees to four foot down then rest of year very unseasonable
1234 third unseasonable year
Wet weather in autumn choked the seed and loosened it.
1236 great floods in Jan, Feb and part of March that no one had seen the like before. Bridges submerged, fords impassable, mills and ponds overwhelmed and sown land meadows and marshes covered. Thames flooded palace of Westminster so small boat could be navigated in the midst of the forecourt. And folk went to their bed chambers on horseback
Followed by dry summer with intolerable heat that all lasted four months. Deep pools and ponds were dried up and water mils useless.
1237 great rains in February, fords and roads impassable for 8 successive days
Turbulent year stormy and unsettled
1238 great floods in many parts probably December
Cloudy and rainy in beginning until spring had passed then the drought and heat were beyond measure and custom in two or more of the summer months. Great deluge of rain in the autumn that straw and grain became rotten and an unnatural autumn which is held to be a cold and dry season gave rise to various fatal diseases.
1239 very wet weather continually from Jan to March, it has continued for four months without intermission.
tonyb