Ole Humlum’s excellent site, Climate4you, has just published the latest Ocean Heat Content data, now up to March 2016. They show some interesting things happening in the North Atlantic.
First, let’s look at the area highlighted below:
Map showing the North Atlantic area within 60-0W and 30-65N, for which the heat content within the uppermost 700 m is shown in the two diagrams below.
Global monthly heat content anomaly (GJ/m2) in the uppermost 700 m of the North Atlantic (60-0W, 30-65N) ocean since January 1955. The thin line indicate monthly values, and the thick line represents the simple running 37 month (c. 3 year) average. Data source: National Oceanographic Data Center (NODC). Last period shown: January-March 2016. Last diagram update 7 June 2016.
We have become familiar with the cold blob, which has developed at the ocean surface in the northern part of the North Atlantic during the last couple of years, but it is evident that it has been getting much colder below the surface as well, down at least to 700 m. Temperatures are now back down to where they were in the early 1990s.
(It is also worth noting that the 1970s marked the coldest period in the record). Unfortunately we don’t have data for the warm 1930s and 40s.