Well, I am too ill due to a cold to continue the electronics work I have been doing, and ire has driven me to tackle an easy subject, the hubristic musings of Ron Clutz. So for a second time in a few days I am breaking my pause from sea ice blogging.
Ron Clutz has recently used MASIE data over a short period to claim that there is a rebound in Arctic sea ice. This has been repeated by that ang of dolts; the Global Warming Policy Foundation. Tamino has already ably dismissed the original claims of Clutz, in Clutz's response it is claimed that 'Nothing alarming is happening to Arctic ice'. The response utterly fails to deal with Tamino's points, just restates the same half arsed nonsense originally asserted.
Clutz is wrong and I will show so in one graph based on NSIDC Concentration data, no modelled data involved just satellite data.
Using Wipneus's calculation of extent and area, which like my own calculations using PIOMAS gridded data is based on Cryosphere Today's regions, it is possible to work out regional extent, area, and compactness. Compactness is a vital metric of sea ice state, it is defined as the ratio Area / Extent and gives a measure of dispersion of ice. One can gain a similar picture using PIOMAS Gice sub grid volume statistics, but to avoid diversionary bleating about models I prefer to concentrate on the compactness metric for this post.
A critical region in the Arctic is the composite region of Beaufort, Chukchi, East Siberian, and Laptev Seas, this is a region I have called the Peripheral Seas (of the Arctic Ocean Basin). The region is shown in red in the following graphic.
This is a critical region because in order to open up late summer inroads into the Central Arctic (green centre of the above map), early melt out of the peripheral seas is needed. Over the coming decades as the Arctic Ocean continues its 'slow transition' to a seasonally sea ice free state, early melt in the peripheral seas is crucial for the Central Arctic to melt out by September. So ice state in the Peripheral Seas region is a critical metric in determining whether the Arctic Ocean's ice pack is indeed stabilising or recovering.
Here is a plot of compactness for late summer in the Peripheral Seas from 1979 to 2015, where late summer is the seven day average centred on 31 August.
If one takes the extent as determining the ice edge, extent being the region with more than 15% ice cover, then in the Peripheral Seas, as their transition towards a seasonally ice free state proceeds, ice cover within the ice edge at the end of summer has dropped from around 60% to 70% early in the series down to around 40% in recent years. 2015 was on the long term trend.
Claims that there is no ongoing deterioration in Arctic sea ice are totally unfounded, and it is safe to ignore those making such claims as being unreliable due to their lack of grasp of the subject.