It is clear that the pattern of melt in the Arctic this year is different from last. It is not clear whether the ice area will be larger or smaller than last year. In any case there will be significantly less ice than in any year except for 2007.
One of the things that is happening is that it remains very warm on the Russian side of the Arctic, with temperatures exceeding 16 C (60F) in such wonderful beach towns as Pevek, (it was 20 C today), near 10 C (50 F) in Tiksi, and Dikson and forecast to be near 20 C in Murmansk. On the other side, things are colder in Barrow and Alert for example, with temperatures near or a bit below freezing.
So let us look at the contenders on August 20. You may have to click on ice maps to get more detail. First we have the official Rabett Run version as recommended by Alastair for which Bob Grumbine can take the blame. It is from NOAA/ National Weather Service National Centers for Environmental Prediction Environmental Modeling Center. Using passive microwave sensing it still shows both the Northwest Passage and the passage near the Russian shore to be blocked, although not by much in each case. This means that Bob gets to decide. . . . .
Next we have the map from the Polar Research Group at the University of Illinois Champaign Urbana, aka Cryosphere Today, which show less ice cover with only minimal blockages in the paths near the Canadian and Russian shores.
And finally from the University of Bremen, Germany, Institut fuer Umweltphysik we have ice area maps, and as a special feature closeups of the NW passage.
Meanwhile the sea ice anomaly is very close to 2 million sq km, and the sea ice coverage is within 0.5 million sq km of last year's record.
Thursday, August 21, 2008