The linked reference indicates that the recent expansion of Antarctic sea ice extent is contributing to the recently observed salinity driven (surface freshening) stratification of the Southern Ocean; which by theory should be making a bigger contribution to Hansen et al (2016)'s positive ice-climate feedback mechanism, than previously thought:
F. Alexander Haumann, Nicolas Gruber, Matthias Münnich, Ivy Frenger & Stefan Kern (01 September 2016), "Sea-ice transport driving Southern Ocean salinity and its recent trends", Nature, Volume: 537, Pages: 89–92, doi:10.1038/nature19101http://www.nature.com/nature/journal/v537/n7618/full/nature19101.html
Abstract: "Recent salinity changes in the Southern Ocean are among the most prominent signals of climate change in the global ocean, yet their underlying causes have not been firmly established. Here we propose that trends in the northward transport of Antarctic sea ice are a major contributor to these changes. Using satellite observations supplemented by sea-ice reconstructions, we estimate that wind-driven northward freshwater transport by sea ice increased by 20 ± 10 per cent between 1982 and 2008. The strongest and most robust increase occurred in the Pacific sector, coinciding with the largest observed salinity changes4, 5. We estimate that the additional freshwater for the entire northern sea-ice edge entails a freshening rate of −0.02 ± 0.01 grams per kilogram per decade in the surface and intermediate waters of the open ocean, similar to the observed freshening. The enhanced rejection of salt near the coast of Antarctica associated with stronger sea-ice export counteracts the freshening of both continental shelf and newly formed bottom waters due to increases in glacial meltwater. Although the data sources underlying our results have substantial uncertainties, regional analyses and independent data from an atmospheric reanalysis support our conclusions. Our finding that northward sea-ice freshwater transport is also a key determinant of the mean salinity distribution in the Southern Ocean further underpins the importance of the sea-ice-induced freshwater flux. Through its influence on the density structure of the ocean, this process has critical consequences for the global climate by affecting the exchange of heat, carbon and nutrients between the deep ocean and surface waters."
Extract: "Now, a new study, published Wednesday in Nature, suggests that sea ice may be one of the major culprits. Using satellite data and models, the authors have shown that Antarctic sea ice has been moving farther and farther away from the continental coastline by strengthening winds in recent years, pouring fresh water farther out into the ocean as it melts.
A recent paper, led by Columbia professor and former NASA scientist James Hansen, suggested the stratification could help force the trapped warm water right up to the bases of marine-terminating glaciers on the Antarctic continent, melting them from the bottom up and leading to an even faster influx of fresh water into the ocean.
“Haumann and colleagues’ findings emphasize that Antarctic sea ice is not merely a passive indicator of climate change and variability, but also a driver of changes in the climate system,” wrote Maksym wrote in his comment. “…
ea ice might have a bigger role than previously thought.”"