Oh l see you are referring to climate shift trends( Interdecadal l think they call it)
I thought you meant annual variation
Well there's a few theories going around as you would know..
The first hurdle to overcome is deciding how much of the climate shift is overlayered harmonic cycles ( destructive /constructive interference) and how much is the chaos theory..
Myself l believe in harmonics, cycles and order.. When there are multiple frequencies involved and they overlay. The overall pattern looks chaotic
The challenge is to, identify the frequencies,separate each of the frequencies and determine their period.
Overlay them all and it would be evident that at some points in time the signal overlap or the amplitude increases ( constructive interference) and sometimes the frequency opposes and can cancel each other out to some extent or to all extent
It is a large task to separate each and understand how they interact with each other
However l agree with what you say in that a la nina , cool Pdo and declining solar activity together are 3 frequencies that produce a constructive effect and causes amplification of that wet cool signal
You would imagine that whilst the SAM remains in mean positive anomaly
and if the polar vortex remains strong etc we will not tend to cool wet
To be cold and wet we would really on the polar and sub polar patterns l would have thought..
Antartica sea ice is increasing maybe this has something to do with position of westerly belt?
Also the temperature gradient between the Nth and south pole is increasing
and the temp gradient between the stratosphere and the troposphere is increasing
Spatial pattern of temp across the globe both vertically and horizontally would have a lot to do with it l would imagine.
What do you think is the cause atm?
Oh by the way . I have been mapping the global synoptics lately
Take what you want from this if at all
I did notice the polar high pressure belt appears to be anonymously south atm
and check out that incursion of low pressure drooping down from Asia which is completely out of place for JULY. accounting for low pressure and moisture high dew points in the dry season up north.
and the high anomaly south of India probably affecting their monsoon
and the nth atlantic high is very west and equatorial atm for july and the low above it is emerging early...
Not sure if those anonalies are annual or a shift associated with 2000 climate shift.
It would take a lot of study and sleepless nights to work that out.
cheers