Eli has read the comments, thought about it a bit more and added another line to the Sea Ice Area graph, showing the maximum amount of new, first year ice formed, the red line above. This is simply the difference between the maximum amount of sea ice in a year less the minimum amount of sea ice area in the preceding Fall.
The amount of first year ice, if anything, is INCREASING. How could that be? To understand this we need to look at Jeff Condon's measure of ice south of 72o North
which is decreasing.
Taken together, a consistent story of sea ice in the Arctic emerges:
1. The area covered by more than one year old ice is decreasing significantly from about 5 million sq km in 1980 to about 3 million km2 now. That is a decrease of 40% in 32 years.
2. The total amount of first year ice south of 72o North has decreased by about 0.75 million km2 in the same period. Condon mentions that there is an average of about 4 million km2 that far south at maximum extent over the 32 years, so this is a decrease of about 20% (Eli is playing horseshoes here, looking for meaning not misleading statistics). Most of this decrease is in areas such a the Baltic, the Sea of Okhotsk and the Bering, Greenland and Barents Seas. So far Hudson's Bay freezes completely over.
3. The ~1.25 million km2 (Rabett eyeball) increase in total first year ice area is entirely from filling the Arctic basin.
4. Summers with major melting are followed by large increases in first year ice from this filling in.
5. The ice pack south of 72o North has both regions which are connected to the Arctic (Greenland, Bering and Barents Seas) and disjoint from it (Hudson's Bay, the Baltic, the Sea of Okhotsk). The former will contribute less in years following significant summer melt which reduces the size of the pack, the latter are sensitive only to local temperatures. A better analysis would exclude the disjoint areas. Eli will have a drink, thank you very much. With ice.