Hi Neven,
yes, that new wind asset is marvellous! If you hit 850hPa you will start seeing the contours of the main Polar Vortex over Foxe Basin. The cut-off ridge, while still over the Pole in the mid-troposphere, now has contributed to a high pressure system over the CAB close to the Chukchi/Beaufort sector.
As Wili posted, the tropopause slopes down from the mid-latitudes to the Pole. But that slope is complicated through the ever changing lobes formed by the Rossby waves. One of these, while based over eastern Europe, was exceptionally extended, creating the cut-off ridge. This propelled some large amounts of energy into the Arctic. Most vivid on 850Mb, 20dC temp anomaly three days ago.
To be fair, I haven’t seen an indication yet that 10Mb temps in the stratosphere are on the rise over the Arctic. But the process should be starting in mid-Asia, as I’ve seen announced on The Weather Centre.
What does keep me thinking and checking, is the slow pace to the same temp anomalies over the Arctic as filed in the ’07-’12 period. The cold fall is now nearly levelled by ‘warm’ December weather. The almost perfect round-up of vortex and cold over North America is striking, as goes too for large positive anomalies over Eurasia and the Arctic Ocean. And the wave patterns…
My thinking shifts from associations with the rapidly rising CO2-content, ocean-atmosphere coupling and maybe not that much pronounced contribution by large amounts of open water last fall. I don’t see a pause. I see the random, mosaic-like pattern in which AGW is shaping up and how our expectations go wrong each new season.
This isn’t a linear, logical process. But, OK, winter still has a long time to go.
