"Martin Rowley" "Waghorn" A 30-35 day oscillation has been reported in
the literature in
association with N Atlantic sector blocking and retrogression of the
jet,this may be a harmonic of a 70 day signal.
Causes may be an internal oscillation involving barotropic interaction
with topography,probably unlikely in the Atlantic,

................................. Your mention of topography had 'little
bells' ringing at the back of my mind of a study that was published
several years ago that directly linked the presence of Greenland with
distortions in the long-wave pattern, but after a search, I can't come up
with that particular entry.
.................................................. ............................................
Whilst searching, I also came upon a few links relating climatological
regime changes over Greenland (from Ice core evidence) and the Asian
monsoon - this implies quite complex and fundamental teleconnections
north-to-south as well as west-to-east: who'd be a climate scientist!



Martin.
Yes,I was precising old notes,but at the time I thought-'Wot about
Greenland?'.
I will look up the original reference and post further if it's illuminating.
There is a note about a possible relation to the Madden Julien Oscillation
as well,

--
regards,
David

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