LOD Revisited for CSALT

One of the most questioned aspects of the CSALT model of global temperature is the LOD to Temperature factor. This creates a multi-decadal variation in temperature useful for optimizing a multiple-linear regression AGW model dependent on CO2 and other factors.

Lunisolar tides impact variations in Length-of-Day (LOD). So does ENSO and QBO. There is a recursive aspect to these relationships as well, since both LOD and ENSO have the same Chandler wobble match in apparent forcing periodicity. This is what I believe generates a 6-year signal that gets identified routinely in the LOD time-series, such as the latest finding in ref [1] below.

From ref [1], the 6-year signal in LOD series. Counting cycles this is close to an average 6.25 year period, close to the 6.4 year Chandler wobble angular momentum variation.

Its a mystery why the LOD may be considered deterministic/periodic based on how well the lunisolar tides resolve the features, but ENSO is only considered quasi-periodic or nearly chaotic (the latter according to Tsonis), even though they likely arise from common mechanisms. Above all, these phenomena all have that curious tie-in to the seasonally aliased Draconic-monthly lunar cycle.

Now we can add this paper by Marcus [2] to the mix. This is a very detailed look at the correlation between long-range LOD variations (longer than the 6-year variation of Ref [1]) and global surface temperature. His application of a 5-year running mean is essentially similar to a 5-year lag that works as a best fit in the CSALT model. Marcus stops short of assigning a source cause for the LOD-to-Temperature correlation, but the general idea is that angular momentum variations are the forcing terms that slosh the sources of heat to the surface -- "via core-induced rotational and/or related global-scale processes".  (I also have to note that Marcus is an independent researcher, who at one time had an affiliation with NASA JPL.)

From Marcus [2], correlation of LOD against various temperature indices.

All these observations of LOD, ENSO, QBO, Chandler Wobble, Flood Return periods have a strong sense of self-consistency (IMO ultimately tied to lunisolar forcing), but the problem is that the discussions are scattered among different research groups. And even on this blog, the discussions reside in scattered postings (and over at Azimuth Project, also see another lunar connection).  Eventually I will write a longer manuscript to tie it all together much like I did with The Oil Conundrum and my old fossil-fuel depletion blog.

References

[1] Duan, Pengshuo, Genyou Liu, Lintao Liu, Xiaogang Hu, Xiaoguang Hao, Yong Huang, Zhimin Zhang, and Binbin Wang. 2015. “Recovery of the 6-Year Signal in Length of Day and Its Long-Term Decreasing Trend.” Earth, Planets and Space 67 (1): 1.

[2] Marcus, Steven L. 2015. “Does an Intrinsic Source Generate a Shared Low-Frequency Signature in Earth’s Climate and Rotation Rate?” Earth Interactions 20 (4): 1–14. doi:10.1175/EI-D-15-0014.1.