I wrote this nine days ago :
June 28, 2010 at 10:16 pm
In three days, the slope of the Arctic extent graph will begin to drop off.
Mark it on your calendar.
Anyone who doubts the correctness of the PIPS based methodology I have been using, should take a look for themselves.
Close up below :
The modified NSIDC map below shows ice loss since the first of the month in red. Where’s Waldo?
The decline in the slope of the area graph is even more dramatic. Area is a better indicator of melt, because it is not affected as much by wind shifting the ice around.
The graph below of average ice thickness shows that 2010 is starting to follow a path more like 2006 than 2007. In 2006 the ice thinned vertically, but did not compress much horizontally. In 2007 the winds compressed the ice horizontally, which led to lots of incorrect news coverage (to this day) that the Arctic was having a meltdown. The average ice thickness actually increased through the summer of 2007.
The video below shows how the winds have changed since earlier in the summer. The ice is no longer being compressed inwards, it is now being stretched outwards by cold northerly winds.
The NCEP forecast for the next two weeks is shown below. Temperatures generally running well below normal in the Arctic. Note – I color shifted the images and scale to make them easier to differentiate. This does not change their data in any way, it just makes it easier to understand.
Temperatures in the high Arctic have been below normal this summer, and in a few days will start their decline towards winter. In 50 days, they will drop below freezing, and remain there.
Meltwater ponds at the North Pole are starting to freeze over.
Julienne from NSIDC wrote this yesterday :
I am not surprised that the rate of decline has slowed a bit during the last week. In the Beaufort and Chukchi seas, the ice has essentially melted back to the lobe of old ice that was transported there over the winter (under the negative AO phase). Thus, this is slowing the ice loss in this region. In the Kara Sea, temperatures have been colder than normal and the winds are causing ice divergence (also helping to slow loss of ice extent in that region).
This is the same point I raised questioning PIOMAS back in April.
The computer model is predicting that 3+ year old ice (which is probably in excess of 10 feet thick) is going to melt by early August. That seems rather far fetched. Below is an overlay of the NSIDC map and the U of W simulation for August 18. Note all the multi-year ice that needs to melt.
Like myself, Julienne has forecast 5.5 million km² for the summer minimum.
Not everyone at NSIDC agrees. Mark Serreze has been quoted as predicting a possible record low, like he does almost every year.
Conclusion : There is nothing going on in the Arctic which hints of a repeat of 2007, other than the highly suspect PIOMAS graph.