Hi Chris,
Sure there is. It's called "Ekman pumping".
Why patronise me with graphics. Do you not think I know about Ekman pumping?
Once again. Here's the difference between PIOMAS monthly average volumes.
Year 2010 2011 2012
Jan 3.14 3.17 3.63
Feb 2.64 2.99 2.51
Mar 2.36 1.99 2.15
Apr 0.82 0.91 0.88
May -2.04 -1.59 -1.61
Jun -4.87 -4.54 -5.43
Jul -6.66 -6.73 -6.37
Aug -4.04 -3.85 -3.96
Sep -1.05 -0.85 -0.99
Oct 1.51 1.32 1.29
Nov 3.22 3.51 3.22
Dec 3.39 3.52 3.78
Maybe that's too complex. How about this.
From April to June there's about 7000km^3 loss.
Then from June to September there's about 11000km^3 loss.
To melt a large proportion of the June to Sept melt between April and June you'd need to melt something like
double the amount that usually melts from April to June. In terms of energy that's an extra 2,338,000,000,000,000,000,000 joules, approximately.
Given that melting peaks in the July minus June difference, this being the period containing the summer solstice, it is safe to conclude that the melt profile is driven by insolation.
Ekman pumping is neither here nor there, the Atlantic Water (AW) layer continues to be separated from the surface by around 100 to 200m. The water there is still cold, just not as cold. As the temperature difference between ice (0degC) and AW is of the order of 1 to 2 degC, the resultant energy flux caused by the temperature difference should the AW come into contact with the ice would simply not be able to deliver the sort of energy flux that insolation can.