From the Institute of Physics
Cold winters caused by warmer summers, research suggests
Scientists have offered up a convincing explanation for the harsh winters recently experienced in the Northern Hemisphere; increasing temperatures and melting ice in the Arctic regions creating more snowfall in the autumn months at lower latitudes.
Their findings may throw light on specific weather incidents such as the extremely harsh Florida winter of 2010 which ended up killing a host of tropical creatures, as well as the chaos-causing snow that fell on the UK in December 2010.
Published today, Friday 13 January, in IOP Publishing’s journal Environmental Research Letters, this new research suggests that the trend of increasingly cold winters over the past two decades could be explained by warmer temperatures in the autumn having a marked effect on normal weather patterns, causing temperatures to plummet in the following winter.
The strongest winter cooling trends were observed in the eastern United States, southern Canada and much of northern Eurasia, which the researchers, based at Atmospheric and Environmental Research (AER), the University of Massachusetts and the University of Alaska Fairbanks, believe cannot be entirely explained by the natural variability of the climate system.
Their results showed strong warming throughout July, August and September in the Arctic, which continued through the autumn and, according to their observational data, appeared to enhance the melting of sea ice.
This warmer atmosphere, combined with melting sea ice, allows the Arctic atmosphere to hold more moisture and increases the likelihood of precipitation over more southern areas such as Eurasia, which, in the freezing temperatures, would fall as snow. Indeed, the researchers’ observations showed that the average snow coverage in Eurasia has increased over the past two decades.
They believe the increased snow cover has an intricate effect on the Arctic Oscillation – an atmospheric pressure pattern in the mid- to high-latitudes – causing it to remain in the “negative phase”.
In the “negative phase”, high pressure resides over the Arctic region, pushing colder air into mid-latitude regions, such as the United States and northern Canada, and giving the observed colder winters.
The lead author of the study, Judah Cohen, said: “In my mind there is no doubt that the globe is getting warmer and this will favour warmer temperatures in all seasons and in all locations; however, I do think that the increasing trend in snow cover has led to regional cooling as discussed in the paper and I see no reason why this won’t continue into the near future. Also if it continues to get much warmer in the fall, precipitation that currently falls as snow will fall as rain instead, eliminating the winter cooling.”
It is also deduced that one of the main reasons conventional climate models fail to pick up on this observed winter cooling is their failure to account for the variability of snow cover, which, as demonstrated in this study, can greatly improve the accuracy of seasonal, and lengthier, forecasts.
“We show in the paper how using the snow cover in a seasonal forecast can provide a more skilful or accurate forecast. Without correctly simulating the coupling of winter climate patterns and the variability of snow fall, the models currently used by Government centres miss an important influence on winter and will therefore continue to be deficient in predicting winter weather on seasonal time scales, and even longer decadal time scales,” continued Cohen.
“In my mind there is no doubt”. There speaks a true scientist with an inquisitive mind.
It’s so cold because it’s so warm.
If it keeps getting warmer, it will get even colder.
Then it will get so cold that it doesn’t get warm anymore, then it will get warmer for good.
I Я a klymut syunteest
That is typical warmist logic. If it cools, it must be because of warming. That is what you should expect from “scientists” with preconceived notions.
The strongest winter cooling trends were observed in the eastern United States, southern Canada and much of northern Eurasia, which the researchers, based at Atmospheric and Environmental Research (AER), the University of Massachusetts and the University of Alaska Fairbanks, believe cannot be entirely explained by the natural variability of the climate system.
The researchers, who swore that they have never in their lives heard of the Eemian interglacial, the Holocene Climatic Optimum, the Roman Climatic Optimum, the Medieval Warm Period, or the Little Ice Age, stated that until very recently every season was the same as the one before: predictable, benevolent, and loving. Only co2 could cause so much unpredictability, and so much raw hate, they say.
warm air causes more snow too…………
We’re going skiing in Miami this weekend
“the trend of increasingly cold winters over the past two decades could be explained by warmer temperatures in the autumn”
Sounds like a negative feedback to me …. I hate it when that happens :))
Reading between the lines, this press release reads like ” no matter what happens with the weather, we have a problem & we need to study it, so keep those grant dollars heading our way ….”
Am I being to cynical ???
So what has happened this year then. Not much snow yet after a very warm autumn!
Repeat after me.”correlation is not necessarily causation”.
I can refute this with one word – Scotland.
So ok can this be republished where they say “colder winters cause warmer summers which cause doomday”.
This paper seems like another “everything is global warming fault” from the propaganda machine.
More proof they know little or nothing about climate, climate mechanisms or climate research. The cause of the current pattern is changes in the Rossby Waves in the Circumpolar vortex from zonal, with few low amplitude Waves, to Meridional with more higher amplitude Waves and is related to a cooling world as the vortex expands. An article on this change as well as its relationship to ENSO and a possible mechanism will be posted to my web site later today.
http://drtimball.com/
I do think that the increasing trend in snow cover has led to regional cooling as discussed in the paper and I see no reason why this won’t continue into the near future.
Finally, climate science has found a positive climate feedback, although of the cooling variety.
Of interest, is that we don’t know why increasing snow cover doesn’t cause runaway cooling and a ‘snowball’ earth.
Do these people have no dignity?
The fact that it snows means that it’s COLD. And it’s not cold because it snows.
Mediaval science to hide the mediaval warming
Modern science to hide modern cooling
Postnormal science to create a postnormal society
I hope 2012 will bring the ratio back in science and politics. This is going nowhere.
Gee, another dumb study. Don’t these people have any better way to waste research grant money??
Now I know why the dinosaurs died out. It was so warm that time that they froze to death eventually.
And yes there were icecaps on Earth during the Eocene Optimum, because it was so warm. The winters must have been very severe during that period.
I think not. More mumbo jumbo in the peer-reviewed literature. It should never have gone through peer-review.
The Law of Parsimony has just been ravaged.
Well this winter hasn’t seemed very warm so far, at least not in the US.
But then again, such surprising weather that doesn’t follow “global warming -> colder winter” would not be unexpected because…well, because global warming itself causes surprising weather.
Large snowcover is cause of negative AO. What causes negative AO is Suns low activity. If polar vortex breaks early, like october, we have large snowcover in northern hemisphere in november.
So that paper has less value than toilet tissue.
Yet we have not had statistically significant warming since 1995, so…
Yes well. Talk about putting carts before horses.
Kindest Regards
As a result of the increase in population, the environmental movement has decided to give its full backing to the latest UN initiative. “DEFRAG” Defrag is part of the sustainable development policy and it involves the preservation of space on earth. It has been decided that space is becoming so scarce, that that which remains should be collected in special areas and preserved for future generations. GSMs (General Space Models) are already predicting that these areas will quickly be filled (with space) and future storage of space will reach a tipping point in the near future
.Makes about as much sense as the article I have just read.
Hasn’t the AO been positive to this point in the 2011-12 winter season thus far? I understand that a shift may be approaching/underway, however.
Tim Ball says
More proof they know little or nothing about climate, climate mechanisms or climate research.
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Ahhh more hyperbole and little regard for intellectual precision.
What it does prove is that they don’t know everything and they are constantly looking to expand their understanding and so now they know more than they did before.
Which is kind of different from the message that they have a preconceived position.
I know someone with not a doubt in her mind that the Americans are degrading her brain with beam weapons. I keep telling her it is global warming, but her absence of doubt persists!
Great, so take an absurd claim “Its colder because its warmer”, then ask a scientist to offer up conjecture on how this might occur, and call it a convincing study..
This is no different than a StarTrek episode where the authors have already written some horriblw story on time travel and then they ask scientist after the fact to try and add some smart words and conjecture on how it may work to the script to make it sound convincing.