"Sea-ice cover in the Barents Sea (from January to March as well in the Kara Sea) again was unusually low, combined with a high pressure area over and in the vicinity of this region. A similar situation has developed over the Labrador Sea, specifically in the second half of March,” Petoukhov says. "As a result, there were inflows of cold air from the northeast to Europe, like we described it in our paper. In addition to that, huge ice-free water surfaces in the north make inflowing air humid. That might be a reason why snowfall is heavy this winter over the above regions.”
Researchers from other institutes came to similar conclusions. Jennifer A. Francis and Stephen J. Vavrus write in Geophysical Research Letters about „Evidence linking Arctic amplification to extreme weather in mid-latitudes“, Ralf Jaiser, Klaus Dethloff et al in journal Tellus A about the „Impact of sea ice cover changes in the Northern Hemisphere atmospheric winter circulation“ and Jiping Liu et al in Proceedings of the National Academy of Sciences (PNAS) about the “Impact of declining Arctic sea ice on winter snowfall”.
More information on the study by Vladimir Petoukhov:
http://www.pik-potsdam.de/aktuelles/pressemitteilungen/archiv/2010/erderwaermung-koennte-winter-kaelter-werden-lassen.
An overview on the connection of ice melting and cold weather and the mechanism described by Petoukhov is also given in a blogpost (in German) by Stefan Rahmstorf, Chair of PIK research domain Earth Systeme Analysis:
http://www.scilogs.de/wblogs/blog/klimalounge/klimadaten/2013-03-19/winter-in-deutschland
