(Image credit: Greenland Climate Research Center)
It’s getting hotter in the Arctic. In fact, the past few days have seen a pretty large temperature spike pushing values 5-9 degrees Celsius above average for much of the region.
Looking at atmosphere and heat maps, it appears that two large blocking patterns are beginning to form. One over eastern Siberia is responsible for a tongue of hot air moving northward into the Arctic. Another appears to be transporting abnormally warm air over Greenland.
(Image source: Earth Systems Research Laboratory)
You can see these temperature differentials setting up on the front side of blocking patterns over Eastern Siberia and Greenland respectively. And on the polar map below you can see a stream of warmer, moist air moving into the Arctic from Eastern Siberia as well. Note the white stream of clouds on the upper left corner of the map.
(Image source: Canadian Weather Office)
So long as this pattern exists, we can expect warmer air to continue flowing into the Arctic. In fact, it is this pattern that has resulted in rapidly climbing temperatures in the region. And a continuation of this pattern would probably result in extended and increased unseasonably warm conditions for most Arctic regions.
With the recent major crack up of Arctic sea ice, a warming pattern may bring on an early start to melt season. We’ll have to keep eyes on the weather. But spring/summer 2013 is already shaping up to be an Arctic melt season to watch.
A high pressure system is currently forming over the Beaufort Sea. According to weather models, this high is forecast to strengthen and move over the North Pole over the next few days, then drift south over Greenland. This forecast shows the high eventually pulling colder air now located over the continents into the central Arctic even as warm air continues to invade from the south over Eastern Siberia.
This is a similar weather pattern to that occurring during the massive sea ice melt event in the summer of 2007. Such a pattern setting up during early spring is not, generally, seen as a threat to sea ice. But the establishment of a strong influx of warm air at the ice edges near East Siberia and Greenland (via the blocking patterns mentioned above) may well encourage melt there. We’ll have to see.
There’s very little sunlight in the Arctic at the moment, so it is not expected that clear skies under this emerging high pressure will result in much melt. Cooler air directly beneath the high may have the opposite effect. Even so, ominous cracks running through the Arctic and a set up similar to what occurred during most of summer 2007 is not necessarily comforting.
Neven’s comment over at the Arctic Ice blog was that “a high like this during May or June would be a disaster.” Read Neven’s take on the developing high here: http://neven1.typepad.com/blog/2013/03/crack-is-bad-for-you-and-sea-ice.html#comments