"Decadal variations" refers to changes or patterns that occur over a period of 10 years. It refers to fluctuations, shifts, or trends that are observed in various aspects such as climate, economy, or population over a decade.
Full definition
Chen & Tung claim that changes in salinity in the North Atlantic is the driver of
decadal variation in ocean mixing, rather than the IPO.
Zhang, Y. - C., W.B. Rossow, P.W. Stackhouse, A. Romanou, and B.A. Wielicki, 2007:
Decadal variations of global energy and ocean heat budget and meridional energy transports inferred from recent global data sets.
The references you gave for variance of insolation reaching the ground in this post are
for decadal variations, in particular mid-century dimming (1950's -1980's), the well known cooling associated with high aerosols, and in fact discussed on SkS.
Are there good overviews as to how much annual /
decadal variation there is in world ocean currents and could unexpected aspects of «trends» in their coupling explain where all the additional trapped energy is going?
The paper... offers a useful framework for
which decadal variations in the global (or northern hemisphere) may be explained via large scale modes of oceanic variability.
On the contrary, irrespective of the framing chosen by their authors, all articles on the pause have reinforced the reality of global warming from greenhouse gas emissions, and this body of work has yielded more knowledge of the processes
underlying decadal variation.
Tropical origins of North and South Pacific decadal variability by Jeremy D. Shakun and Jeffrey Shaman makes some very interesting findings suggesting that both the northern and southern Pacific Ocean has evidence of the Pacific
Decadal Variation PDV being...
Relationship
between decadal variations in temperatures in the Pacific and the tropopause identified From the HELMHOLTZ CENTRE FOR OCEAN RESEARCH KIEL (GEOMAR) Water plays a major role for our planet not only in its liquid form at the surface.
So, the most common and by far the largest forcing at any given time is
multi decadal variations in energy emissions from the oceans.
Discussion of
decadal variation seems not to exist while the likes of Goosse et al 2009 and Holland et al 2008 appear to be discussing annual variation (like 2007 & potentially 2012).
Let's look in more detail at the paper's key figure, the one that looks at past and (forecast) future global temperatures, «Hindcast /
forecast decadal variations in global mean temperature, as compared with observations and standard climate model projections» (click to enlarge)
Dr. Curry Paper
on decadal variation: We find that the strongest cross-correlation of the decadal fluctuations in land surface temperature is not with ENSO but with the AMO
Borehole reconstructions aren't able to give annual or
even decadal variation, yielding only century - scale trends.
And eventually, explains Dr. Johann Jungclaus, «the anthropogenic climate change and the
natural decadal variation will add leading to a much stronger temperature rise.»
No mention is made of ENSO or
Pacific decadal variations that dominate interannual and decadal variability in the real world, and which are a key to understanding the recent hiatus, and recent trends that are not representative of longer - term trends, although frequently interpreted as such.
The blue curve is a smoothed depiction to capture
the decadal variations.
The Pacific Ocean dominates
the decadal variations of global heat content during these two periods.