This is known to be of utmost importance. If the lower salinity lens on the surface is mixed away or exported, then there is much too much thermal energy in the Atlantic and Pacific warmer, saltier layers beneath for the central Arctic Basin to refreeze in winter. Data is scarce due to only one drift buoy still active this year.
Woods ITP97 has for nearly 500 days been transiting from near Bering towards the CAA across some of the deepest parts of the basin.
The Temperature and Salinity plots show some interesting incontinuities that seem to suggest to me areas of surface/depth mixing, where the Halocline has ruptured.
Perhaps even better illustrated by the Dissolved Oxygen plot.
The Copernicus salinity models are obviously not as fine a resolution as what the Buoys are measuring. The 5m Salinity fronts actually do not appear to have changed much 2012-2017. But the Thickness of the surface mixed zone appears to be increasing throughout the basin.
hope these animate if you click them. 1 colour bar is 25m on the Thickness plot so we have the CAB gone from less than 25m surface mixed layer to up around 75m in five years it seems: