In that vein, relocating this post I made from elsewhere.
plinius Today at 12:59:56 PM
: jdallen July 13, 2015, 04:49:27 PM
It's optimal melting conditions for sure, combined with some drift; modest surface winds have been shoving the pack from the Northern Laptev towards exits to the Kara and Barents around Franz Josef and to a lesser degree towards the Fram
/end jdallen
Fully agreed, but the main question was why this position is open frequently. Wind pattern/drift certainly plays a role, but after all the fact that it happens downwind from the New Siberian islands, which produce a trough in the ice thickness north of them if the transarctic drift is on, should not be neglected.
/end plinius
Watching patterns in Climate Reanalyzer, I've found it useful to track the flow of moisture.
Pretty persistently, we have a "dry" side - towards Greenland - and a "wet" side, along the Siberian coast. Now mind, it's not persistent or pervasive, but during the last two weeks of following the changing forecasts and looking at current conditions, I see three major flows of moisture feeding into the Arctic.
The strongest is is from the Pacific side, along the East Asian margin, which breaks against the "RRR" SE of the Gulf of Alaska and then by that gets redirected north - either through the Bering or across the Canadian Rockies and then splitting with part heading east and south and part heading due north into the southern Beaufort.
The second is a flow from SE Asia around the eastern margins of the Himalayas and Gobi, north across Siberia, and dumps into the Eastern Laptev and ESS.
The last is a flow from the eastern Europe that hits the western Kara and merges with Atlantic flow following the gulf stream.
There seem to be two primary outlets of Arctic air displaced - one is across extreme eastern Siberia, which isn't as consistent as the one which runs most typically out across Svalbard-Franz Josef breaking out slantwise down into the Greenland sea.
It seems a reasonably persistent pattern, at weekly scales, and how it seems to be running fits what I'd expect with the heat exchanges and ice melt we've been seeing - Kara getting smashed by flows out of Europe, Bering/Beaufort/Chukchi by flows across out of the Pacific, ice backing up against Svalbard and Franz Josef and somewhat cooler conditions in the CAB.
I'm interested to get others take on it.