I saw this image in this answer to the question Noctilucent clouds and anthropogenic climate change which was listed as related to the question “New” cloud types: Can they be used as markers for climate change observations?.
The answer says:
In recent observations, reported in the NASA article Unexpected teleconnections in noctilucent clouds in 2014 found that the winter air temperature over the USA and Arctic stratospheric conditions have a direct link to the frequency of NLC over Antarctica (as per the image below from NASA):
At first glance I thought it was an illustration of coincidental correlations until I realized that it's arctic and not antarctic and so they are in the same hemisphere.
Question: But I'm curious, was this still a one-off 45 day coincidental correlation, or has this happened again in 2015 and 2016?