The current Arctic cyclone has been quite intense. 968 vs 963 for the GAC. Looking at Canadian Analysis charts it covers only a fraction of the Arctic basin, compared to GAC covering the majority. However the squeeze against the high pressure towards the Siberia Sea looks to have produced tighter wind gradients and presumably stronger maximum winds than the GAC, but over a relatively small area.
What struck me with this cyclone is the intensity of the associated warm air mass over Siberia. After the central Arctic has generally been a little on the cooler side (compared to recent years, but still warm compared to longer term stats). Temperature contrast plays a big role in cyclogenesis. And while much has been said about Arctic amplification, and warm arctic cold continents, I think the situation may be reversed in summer. During summer, particularly early summer the Arctic is still dominated by ice. This pins the surface air temperature close to 0 and the basin is pretty similar to what it was several decades ago. The surrounding regions are getting warmer, thus we have warm continents, cold Arctic, and increasing frequency/intensity of Arctic cyclones.
And some seasons we see a transition from strong high pressure dominated weather early in the melting season to low pressure dominated weather. 2010 and 2011 really stood out as seasons that early on had severe melting weather, with some dramatic (at the time) early season stats, but then fell flat quite significantly as cyclone dominated weather took hold. 2013 was the year of the persistent arctic cyclone where the cyclones started early and just kept going. While the surface temperature may be pinned close to 0, the atmosphere above has been getting warmer (eg 925hp temps). But when we get a significant cyclone, mixing of the air column with the surface pinned at 0, plus clouds etc result in the relatively cool surface extending through a more significant portion of the atmosphere, thus increasing the warm continent cold arctic temperature contrast and making further cyclones more likely.
So negative feedback. But perhaps only sometimes. In 2012 we saw both early season cyclones that failed to establish a more persistent cyclone shield, but spread the ice and allowed intermittent high pressure weather to pump lots of heat into the mix of ice and open ocean, and then the very severe GAC. The GAC was of course followed by massive loss of ice, although there is an argument that the ice had already been set up to melt by previous conditions and the GAC played a relatively minor role.
