A little over six weeks have passed since I wrote the last blog post on the Northwest Passage (NWP): Still chock-full of ice. Since that post the NWP was hidden most of the time by clouds, no telling really what was going on down there. In the last couple of days I noticed on the sea ice concentration maps as put out by the University of Bremen that ice concentration in most of the NWP was very low. This has now been confirmed by satellite images:
I don't think it will be declared open officially yet. There is still some ice rubble here and there in Parry Strait and Lancaster Sound, and ice in the Beaufort Sea is still blocking McClure Strait for now. But the rubble will clear and the ice will pull back, making the NWP navigable for the fifth time in six years (previously in 2007, 2008, 2010 and 2011). With the Northern Sea Route almost open as well, we witness yet another summer in which both Arctic sea routes have opened up. This was a very rare occurence in the past, but has already become almost normal in current times.
This year's opening up of the NWP is quite early for the time of year, which is surprising, because the passage was still full of fast ice only one month and a half ago. However, as mentioned at the time the concentration of multi-year ice in the region was well below the historical average and although seasonal first-year ice had thickened a bit more than usual because of an anomalously cold winter, it would likely clear during the melt season.
Temperatures have been about 3 °C above average in the past six weeks over most of the passage and that doesn't help either: