Our simulations show that melt ponds start to form in May, a maximum extent of 18% is reached in the climatological mean at mid-July, and there are hardly any exposed ponds left by mid-August. The strong interannual variability and the positive trend are striking. Whereas in 1996, the year with the highest September ice extent since 1979, the maximum pond fraction reaches only 11%, in 2012, the year with the lowest September ice extent, up to 34% of the sea ice is covered by ponds.
[T]he melt-pond fraction in May seems to have the strongest impact on the sea-ice state in the subsequent September. Our results confirm that the early melt season is decisive for the strength of the summer ice retreat.(...)We conclude that the inclusion of a realistic melt-pond model will transform future forecast and climate models in the Arctic regions and beyond.
For September 2013 we forecast a mean ice extent of 5.55 0 ± 44 million km2, which is closer to the observed mean value of 5.35 million km2 than any of the 23 statistical,model and heuristic predictions presented at the Arctic Sea Ice Outlook webpage in July (median value of 4.0 million km2).
http://neven1.typepad.com/blog/2014/04/more-on-melt-ponds.htmlWhen Arctic melt ponds are sufficiently connected, as pictured here, they exhibit a property called universality that researchers believe is common to all complex, correlated systems.