I worked on something similar, but more more simplified, thing to yourself for my undergraduate dissertation last year.
Related to the dipole, I created an index around the Fram Strait using NCEP/NCAR reanalysis data SLP for two pairs of points, seen in the image below.
I figured that to enhance sea ice export, you need the air flowing towards Fram, and from the strait itself toward the Greenland sea, helping to reduce summer sea ice extent (my understanding has come along some way since then!).
Anyway, the index worked off the monthly data, and whereby if the pressure on the western points are higher (lower) than the east, you'd get enhanced (subdued) summer export and reduced (increased) extent. So basically a pressure difference index.
Here's what I got for the Summer timeseries.
The 2007-2012 period had the highest 6 year mean for the index for June also, with this year being the first below average June since 2005.
I suspect it would be closely related to the pressure pattern your working on.
EDIT: Also, I think you'd find it hard to differentiate your pattern from the NAO loading pattern http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao_loading.html