Arctic Oscillation

[neufer]

[img]http://earthobservatory.nasa.gov/images/imagerecords/47000/47880/arcticlsta_amo_2010337_palette.png[/img]

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<<The first week of December was a chilly one for much of Europe and parts of the United States. This image shows the temperature of the land surface for December 3-10, 2010, compared to the average temperature for the same period between 2002 and 2009. The measurements are from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite.

Clearly, 2010 was cooler than average in northern Europe and the eastern United States. Greenland and parts of northern Canada, however, were exceptionally warm. This temperature pattern was caused by the Arctic Oscillation.

The Arctic Oscillation is a climate pattern that influences winter weather in the northern hemisphere. It describes the relationship between high pressure in the mid-latitudes and low pressure over the Arctic. When the pressure systems are weak, the difference between them is small, and air from the Arctic flows south, while warmer air seeps north. This is referred to as a negative Arctic Oscillation. Like December 2009, the Arctic Oscillation was negative in early December 2010. Cold air from the Arctic channeled south around a blocking system over Greenland, while Greenland and northern Canada heated up.

The unusual cold brought heavy snow to Northern Europe, stopping flights and trains early in December. Cold temperatures and snow also closed roads and schools in the eastern United States and Canada during the first week of December. The diagonal path of a powerful winter storm is visible as a streak of cold across the Upper Midwest of the United States.>>

[BMAONE23]

Sounds to me like a system that isn't driven by temperature variations but rather drives temperature variations through pressure gradients.

[neufer]

Sounds to me like a system that isn't driven by temperature variations but rather drives temperature variations through pressure gradients.

Sounds to me like a system that is driven by (global warming augmented)
ice free North Atlantic sea surface temperature anomalies:

[b][color=#FF0000]Sea Surface Temperature Anomalies[/color][/b] on Dec. 16, 2010

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[neufer]

Heavy snow in Europe causes travel chaos
Last Updated: Saturday, December 18, 2010 | 9:26 AM ET
CBC News

<<Travellers are being warned to expect severe travel disruptions all day Saturday across Europe because of heavy snow and freezing temperatures. London's Heathrow and Gatwick airports have closed because of snow and ice, and British Airways has suspended all domestic and European flights. At Gatwick, dozens of snowplows were deployed Friday in an effort to clear the airport's runway before operations were shut down. Simon Calder, a travel writer for The Independent newspaper, said Heathrow usually handles more international travellers than any other airport in the world. 'That means just from [British Airways] alone, we are certainly going to see 20,000 or so people booked on long-haul flights who won't be travelling out of London. And everywhere from Nairobi to Entebbe to Cape Town to Los Angeles people who are stranded, trying to get back to Britain won't be travelling either," he said. The airline said it expected flights would remain grounded for much of the day.

Hundreds of flights have been cancelled at airports in Switzerland, Germany, Denmark, France and the Netherlands. In Poland, cold weather is hampering train service. To the south, in Bulgaria, nearly a metre of snow was reported on Friday. The main highway and airport in Varna was closed for several hours.>>

[jaksichj]

I am not skeptical of global warming --as I am-- still attempting to understand it's repercussions in the near future--

My question would be --would it be safe to assume that the current climatic changes will eventually produce much higher temperatures in the intermediate future?

[neufer]

I am not skeptical of global warming --as I am-- still attempting to understand it's repercussions in the near future--

My question would be --would it be safe to assume that the current climatic changes will eventually produce much higher temperatures in the intermediate future?

The main problem is with Arctic Ocean sea ice melting and its influence upon Northern Hemisphere weather.

[rstevenson]

Also worrisome... the warming of Arctic land masses and shallower waters, leading to the melting of areas now in perma frost or under extremely cold water even when there's no ice, said warming leading to the release of large amounts of methane currently trapped.

Rob