In
response to your question I would refer you to my comment above Dave Wendt (14:39:39): where I discuss the Rigor and Wallace paper of 2004 which demonstrated that the decline in sea
ice age and thickness began with a shift in state in Beaufort Gyre and the TransPolar
Drift in 1989 which resulted in multiyear
ice declining from over 80 % of the Arctic to 30 % in about one year and that the persistence of that pattern has been responsible for the continuing decline.