Europe hammered by winter, is North America next?

Europe hammered by winter, is North America next?
This map shows temperature anomalies for Europe and western Russia from January 25 to February 1, 2012, compared to temperatures for the same dates from 2001 to 2011. The anomalies are based on land surface temperatures observed by the MODIS instrument on NASA’s Terra satellite.

For the first half of this year's winter, the big news was warm temperatures and lack of snow. Ski resorts were covered in bare dirt, while January temperatures in southern California topped July highs.

Then, out of the blue, Europe got clobbered: Over the past two weeks, temperatures in have nose-dived to -30 degrees Celsius (-22 ). Blizzards and the bone-chilling cold have resulted in the deaths of over 550 people so far, with rooftop-high snow drifts trapping tens of thousands of villagers in their homes and cutting off access to entire towns. It has even snowed as far south as North Africa.

NASA Bill Patzert of the Jet Propulsion Laboratory explains what happened: "A couple of weeks ago, Mother Nature did an about face. The tight that had bottled up the cold arctic air in the beginning of winter suddenly weakened. Cold air swept out of Siberia and invaded Europe and the Far East."

The "tight polar vortex" is caused by the Arctic Oscillation (AO), a see-sawing pressure difference between the Arctic and lower latitudes. When the pressure difference is high, a whirlpool of air forms around the . That’s what happened earlier this winter: the whirlpool was more forceful, corralling the cold air and keeping it nearer the pole.

Now the vortex is weakening. With "the AO Index going negative," as an expert or weather-nerd might put it, escapes from that whirlpool and heads southward, resulting in the killing extremes now plaguing the other half of the planet.

However, even the breakdown of the cannot completely account for the severity of the winter Europe is suddenly experiencing. As strange as it sounds, some climatologists, among them Judah Cohen of Atmospheric and Environmental Research in Massachusetts, attribute the unusual cold to global warming. Cohen contends that since sea ice is being melted by warmer temperatures in the Arctic, more moisture is available for the atmosphere to pick up – and drop as snow. As a result, Siberian snow cover has increased, and this snow cover has a cooling effect which reaches East Asia and Europe.

"Cohen's research is cutting edge and could bring important improvements to forecasting climate and weather over North America and Europe," says Patzert. "Cohen and others are on the threshold of understanding of how climate change affects the behavior of the Arctic Oscillation1."

Patzert adds, however, that this winter is just one of many severe winters that have changed European history. "Looking back, Mother Nature has taken us on some very wild rides."

He cites the winter of 1683/84, when the Thames River in England stayed frozen with a thick layer of ice for nearly two months, as an example.

"And let’s not forget the frigid winter of 1812, when Napoleon's Grande Armee was decimated by the extreme cold in Western Russia."

Patzert notes that European history would have been much different if Napoleon had had a good meteorologist on his staff and some satellites to warn him about what he was marching into.

"And the turning point of World War II occurred in 1941, when Germany’s forces were nearly frozen in place," he adds.

There are many other examples2, and climate change can't be blamed for all of them.

"There's always going to be some natural variability. Every episode of high temperatures or extreme cold isn't . Sometimes it's just weather!"

The weakening could soon bring a return of winter to North America as well, although Patzert doesn't expect it to be as severe as what's happening on the other side of the Atlantic.

Is there any relief in sight for Europe?

"The good news is that this crippling cold snap arrived mid-winter. With the vernal equinox less than six weeks away, this AO episode will become muted – hopefully."

Hang on till Spring."


Explore further

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Citation: Europe hammered by winter, is North America next? (2012, February 17) retrieved 20 June 2019 from https://phys.org/news/2012-02-europe-winter-north-america.html
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Feb 17, 2012
agreed, LB. one of the accepted hypotheses of GW is that Arctic ice melt will create a pool of freshwater which will float on top of the denser salt water, shutting down the Gulf Stream. Without the Gulf Stream, Europe and UK temps will drop to the level of Nfld/Labrador (same latitude). So if the Gulf Stream is stymied, the current still has to 'go somewhere'. It appears that the east coast of North America is benefiting from its warm waters giving us a more temperate winter in east coast america. It is possible that the 'freshwater dome' over the Arctic has caused this to happen, and the chill over UK and Europe may be permanent.

Xbw
Feb 17, 2012
Patzert notes that European history would have been much different if Napoleon had had a good meteorologist on his staff and some NASA satellites to warn him about what he was marching into.


Yeah it would have been much different if Napoleon had satellite technology. He would have just launched ICBMs :)

Feb 17, 2012
Why is this strange? Its a well known "theory" that global warming actually causes global cooling by melting the ice and slowing or stopping the ocean conveyer belt.

Oh boy. Would you please look up the difference between 'climate' and 'weather' before posting again on global warming issues? Thank you oh so very much.

Feb 18, 2012
I think everyone knows the whole frozen Europe is from a shift in the jetstream from global warming and excessive evaporation of water from the Pacific. Mix in the additional methane releases in the upper latitudes from the arctic peat bogs...

Yeap, a sure fire AGW effect if there ever was one.

Feb 18, 2012
If its an AGW event then why isnt the British Isles and Western Europe suffering, The fact that only the bulk landmass remote from ocean is predominantly suffering from the freeze, indicates that the Gulf stream is alive and well. As to what I think is the precursor I am forbidden to state because it is outside the mainstream thought regarding physics, and therefore branded pseudoscience.

Feb 18, 2012
"...Blizzards and the bone-chilling cold have resulted in the deaths of over 550 people so far,..."

More in just 2 weeks than in the extreme summer heat western Europe experienced several yrs ago.

So lets hope that AGW restarts soon!!

Mar 09, 2012
the average course or condition of the weather at a place usually over a period of years

Note the 'years' in that sentence? And all global warming scenarios predict more extreme winters. Global warming does NOT mean that all days will be warmer and that every place on earth will experience an equal amount of warming. Some will even cool down. But the AVERAGE global temperature will (and does) rise.
So weather will get more extreme (with ups AND downs) but climate will get warmer.

Arguing from a particularly cold winter ("Wal, I had me a big pile of snow dis year - global warming must be a hoax") in a part of the world against global warming is just stupid because it confuses weather with climate.

The world is a wee bit bigger that Europe (or the US). 70% of it isn't even land.

Mar 09, 2012
more moisture is available for the atmosphere to pick up and drop as snow.

There is a narrow temperature range where snow can occur.
More snow, more glaciers, higher albedo, ...ice age, again.

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