Maybe someone with more knowledge of sea salinity/temperature will provide a more accurate scientific explanation but my very basic understanding so far is that the Atlantic ice front could be a long subduction zone where, in calm weather, warm salty water would normally sink beneath the cold fresh meltwater. Stormy weather running along the ice front will cause mixing and may delay freeze.
Mercator 0m salinity, sea temperature, anomaly and concentration for sep21.(400KB)
Very small windy wave update, sep22-oct1(1.2MB)