Arctic and Southern Ocean air temperature

The graphs below are inspired by the temperature graphs that used to be available on Andrew Slater's  website, which was discontinued after Slater's early death in 2016.  

The graphs below use NCEP reanalysis data, both for surface temperature and for the temperature at the 925 millibars level.  The temperature is averaged (with proper area-weighting by latitude) over a region in the Arctic Ocean similar to the region Slater used.  The red parts in the image below show Slater's region.  The region that I use is an approximation of that one, but since NCEP reanalysis only has a resolution of 2.5 degrees for both longitude and latitude, the approximation is rather coarse at some places.  Grid cells that lie near the coastline are weighted by the percentage of ocean pixels they contain, i.e. land pixels have weight zero in the calculations.

Regional temperature at 925 mb

Southern Ocean 925mb temperature

The Southern Ocean is divided in 5 regions.  The northern edge of each region is defined at 66.25°S near the polar circle.