It must be snowing.

[Vergent]

Talk about bad timing.

http://iopscience.io.../014007/article

The study would seem to be upended by this mild winter, which follows a warm Arctic. So what gives?

"The paper does not claim that every winter will be cold," says Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research, a for-profit weather service.

It turns out Eurasia snow cover in October was low. Why?

http://usnews.msnbc.msn.com/_news/2012/01/13/10141999-cold-winters-tied-to-arctic-summers-study-says

[donsutherland1]

Talk about bad timing.

http://iopscience.io.../014007/article

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http://usnews.msnbc....mers-study-says

Thanks for posting the paper. It will make for interesting reading. I suspect that the cooling witnessed during DJF in parts of the Northern Hemisphere might be linked to the cyclical decline in the AO (and there is a longer-term cycle with the AO). The AO is an important component for forecasting winter temperature anomalies. I don't believe the cyclical change in the AO debunks the long-term observed warming that has been underway in the Northern Hemisphere (annually), including the decades referenced by the paper.

[BethesdaWX]

I don't believe the cyclical change in the AO debunks the long-term observed warming that has been underway in the Northern Hemisphere (annually), including the decades referenced by the paper.

I agree, well at least it doesn't debunk it in this way. The -AO decreases cloud cover anomalies from the pole to about 40N, while clouds are increased from 30N to 0N. The AAO has the same effect, a +AO may lead to artificial atmospheric cooling in the NH due to the cold vortex and the knowingly variable temp anomalies at the higher lattitudes which skew reality of the change in true , but there will be more SW radiation incoming into the ocean waters in the tropical regions which was one of the reasons for the warming we saw.

So it's known a 1% change in low and/or mid level clouds in the tropics equates to about 1.1W/m^2 of RF change even when heat trapping by the clouds preventing LW escape is taken into account. The AO can cause significant variation in the total atmospheric albedo.

[donsutherland1]

It was an interesting paper. As I suspected, the paper points to the AO as being responsible for December/January/February (DJF) pattern in the Northern Hemisphere since 1988. It links above average Eurasian snowcover in October as a driver of the AO. It suggests that it is an open question as to whether the observed trend is "a consequence of internal variability or a response to changes in boundary forcings rusing from climate change." It further notes that internal variability does not entirely explain the trend. Finally, the paper also notes that the impact of the ENSO, PDO, AMO, and solar activity was tested and that the direct impact of those factors was "negligible" in explaining the observed trend in the DJF pattern in the Northern Hemisphere since 1988.

[BethesdaWX]

Finally, the paper also notes that the impact of the ENSO, PDO, AMO, and solar activity was tested and that the direct impact of those factors was "negligible" in explaining the observed trend in the DJF pattern in the Northern Hemisphere since 1988.

Thats because they're not correlating those aspects correctly, the Sunspot cycle is irrelavent. The Sun's magnetic poles, Interplanetary Magnetic Field, and Solar Wind are the factors that lead to the true correlation which runs on a 3 year lag [see my thread for peer reviewed evidence].