Thanks pj!

Here's a link to the entire study:

http://advances.sciencemag.org/content/4/8/eaat6773

It's been interesting that the global warming of just over 1 deg. C in the past 150 years has been most concentrated at the highest latitudes of the Northern Hemisphere. Near the North Pole it's something like +3 deg. C

The greatest warm temperature anomalies by far have been in the Arctic Winters. This makes sense if there more open water vs ice.  There isn't much sunshine in the Winter and temperatures usually just keep getting gradually colder. Having a snow/ice covered surface would trap any ocean heat from getting into the atmosphere. If the surface, instead is open water, then heat can be released into the atmosphere.

More comments later when I get the chance