I had grown accustomed to writing Barentsz Sea without the Z, as everyone does. But I've decided to no longer scorn my Dutch roots. The Barentsz Sea has been named after Willem Barentszoon, a Dutch explorer and cartographer who died looking for an open Northeast Passage (now known as the Northern Sea Route) towards the end of the 16th century. At that time family names weren't used universally yet, and many people went through life with just a patronym, just like in Russian classic literature. Hence Willem was known as Barentsz., short for 'Barents zoon', the son of Barent.
The Barentsz Sea and its neighbour the Kara Sea are giving us an exciting prelude this year, as we await the melting season to start in about a month and a half from now. Large swathes of sea water that ought to be frozen by now, are still open or have opened up in the past fortnight.
According to the Norwegian Meteorological Institute this is what an average January (1976-2006) looked like in the region:
And this is how it looks now, one week into February:
The difference is quite marked, but that has a lot to do with the 30 year baseline that comprises many years that had even more ice cover than shown on the map with the average from 1976 to 2006. And so, as usual, I have downloaded Uni Bremen sea ice concentration maps from years of the recent new Arctic regime (2005-now), and cropped them, so they can be compared to the current situation:
I have been looking at the Arctic sea ice from up close for about two years now, but this is definitely one of the most spectacular things I have seen so far. Two weeks ago 2012 somewhat looked like 2006 and 2008 (although there already was more open water around Svalbard and Novaya Zemlya), but where the ice cover grew in those two years, it just keeps on getting smaller this year. It's almost as if the melting season has already started in the Barentsz and Kara Seas, two months earlier than normal.
What could be causing such an early retreat of sea ice cover? The answer is probably manifold. First and foremost is the big high-pressure system over Northern Siberia that formed about 10 days ago and is helping Ded Moroz to hold Europe in a late frosty grip. At the same time this high draws in winds from the west, pushing the ice back in the Barentsz and Kara Seas. These winds also bring warm air and rain from the North Atlantic. Take for instance this data from the weather station at Svalbard for the latest 30 days:
Average temperature was -3.3 °C, 12.2 °C above the normal. Highest temperature was 4.8 °C (29 January), and the lowest was -15.0 °C (25 January). The total precipitation was 61.3 mm. Highest daily precipitation was 25.9 mm (30 January).
And of course the winds probably take the warm waters from the North Atlantic Current some further still into the Arctic, to places where the sea water that was already exceptionally warm last melting season never really cooled down enough (relatively speaking) for some proper ice formation:
One last factor that is not exerting a great influence right now, is sunshine. Solar radiation melts ice directly and indirectly by warming up sea water. Due to the Earth's axial tilt the Arctic receives very little of it during winter, but slowly the Sun's rays creep northward every day, reaching more and more of the frozen land and sea surface.
To give an idea, here's a sun chart from the University of Oregon that shows the angle of the Sun over Kara Strait (70N, 57E), the channel of water between the southern tip of Novaya Zemlya and northern Russia that connects the Barentsz Sea with the Kara Sea:
The Sun is barely rising over the horizon right now and remains visible for only a couple of hours. But this will soon change and it won't be long before there is enough light for us to start gazing at the MODIS satellite images. Whether the sea ice will retreat even more in the meantime or whether we will see a late freeze-up in the Barentsz and Kara Seas, remains to be seen. But as things currently stand, the Atlantic side of the Arctic looks spectacular. Spectacular and ominous.