The possible stratosphere link is very interesting. Not really SSWs,
but it stops me wondering where the research was!

Again, TY.

Well the teleconnection from the Tropical Pacific to Europe in late
winter appears to be facilitated by
a stratospheric pathway - which is dependent on a frequency modulation
of SSW events. There are a few more papers on the ENSO-Stratosphere
pathway
in the literature which show that it is changes in stratospheric
variability (SSWs) which are important for the cold European response.