Ian Wilson: LOD, Precip, Temperature and Atmospheric Angular Momentum

Posted: September 15, 2012 by tallbloke in atmosphere, climate, Cycles, general circulation, Ocean dynamics, Solar physics, solar system dynamics, Tides, weather

Reblogged from Ian Wilson’s excellent website.

The following discussion is based upon a WUWT post
that highlighted a paper called:

Persistence in California Weather Patterns
by Jim Goodridge – State Climatologist (Retired)

which can obtained from:
In this paper, Goodridge notes that the accumulated departure
from average of 47 Californian de-trended temperature records
(figure 1) shows a remarkable similarity with the accumulated
departure from the average Pacific Decadal Oscillation (PDO)
(figure 2).
Figure 1:
Figure 2:
Goodridge notes that link between the PDO and Californian
land surface temperatures is provided by the prevailing coastal
wind directions on the Californian coast that are associated
with the rising and declining phases in the accumulated departure
from the average PDO.
The accumulated departure from average plot of the PDO 
index has a peak in about 1944 as well as during the current 
period of heating starting in 1975. The rising limb of this 
PDO index represents a warming period of SST on the 
West Coast coast, where as a declining trend represents 
a time of cooling. In general, cooling on the US Pacific 
Coast occurs when coastal North winds induce offshore 
coriolis force that result in off shore winds that lower tides 
that induce cold-water upwelling. This reflects the delicate 
hydrostatic balance of the oceans. Warming SST is associated 
with South winds that induce an onshore coriolis force with 
higher tides, which suppress cold-water upwelling.”
In addition, Goodridge notes that the variations in the Earth’s
Length-of-Day (LOD), a quantity that is inversely related
to the Earth rotation rate, appears to closely match the
observed changes in the accumulated departure from the
average PDO (compare figure3 with figures 1 & 2):
Figure 3:
The remarkable thing is that the changes in the LOD appear to
preceed those observed in the accumulated departure from the
average PDO [and the accumulated departure from average of
47 Californian de-trended temperature records] by about seven
to 10 years! This means that the latter are causally linked to the
Goodridge provides a possible explanation for this causal link:
“The PDO index is a measure of the East West sea surface 
temperature difference in the North Pacific Ocean. The 
AAM index [closley linked to the LOD] is a measure of the 
ratio of East West vs. North-South winds on the planet 
that affect the earth rotation rate.
  1. tallbloke says:

    Another remarkable thing is that longer term changes in LOD correlate with the motion of the sun and planets WRT the solar system centre of mass, as the first post on my blog showed. Subsequent posts have demonstrated a correlation between that motion and solar activity levels.

    Leif Svalgaard says:
    September 15, 2012 at 9:17 pm
    RACookPE1978 says:
    September 15, 2012 at 7:41 pm
    if (big if there) 10Be ratios relate to solar energy that we believe are related to TSI levels, when did that change in solar energy occur, and when did the changes in fusion that caused the original change in solar energy occur?
    99.9% of TSI comes from the fusion in the core [which does not change on time scales for which we have data], the remaining [variable] 0.1% comes from changes to the surface magnetic field.

    cut – paste – save.

    Thanks Leif. I’ll quote this back to you the next time you use the argument that it’s not possible that the planets are affecting the sun contemporaneously because it takes ever so long for energy to get from the core to the surface.

    All systems with feedback oscillate. The solar system is such a system. The longer term oscillations in the suns core might easily exhibit a 0.1% variability over a few hundred years since the nadir of the little ice age and the Maunder Minimum in solar activity.

    It is estimated that global average surface temperature may have risen around 1.5C since then. If so, this is around 0.5% of the Earth’s absolute temperature in Kelvin. Prof Nir Shaviv identified an amplification of solar variation of around 5-7 times in the climate system by using the oceans as a calorimeter. This was likely caused by a reduction in cloud albedo, which is empirically found by the new Spanish and Chinese studies to be contemporaneous with the above averagely active sun of the late C20th.

    It appears then that the Sun can account for most or all of the climate variation we have observed and reconstructed from proxies, given various lags and leads associated with natural internal variability from, for example, oceanic oscillations.

  2. Ninderthana says:


    Thank you for highlighting one of my attempts at highlighting one of Anthony Watt’s WUWT’s posts. The last little quote in the article is the most revealing:

    “The PDO index is a measure of the East West sea surface temperature difference in the North Pacific Ocean. The AAM index [closley linked to the LOD] is a measure of the ratio of East West vs. North-South winds on the planet that affect the earth rotation rate.”

    The logic here is that the relative strength of the zonal (east-west) winds compared to the meridional (north-south) winds are linked to changes in the Earth’s rotation rate as well as
    the patterns of (east-west) sea surface temperature differences in the North Pacific (also known as the POD).

    What is really telling is that:

    a) long-term changes in the PDO appear to be linked to long-term deviations in the Earth’s rotation rate [with the latter preceding the former by about 8 years).

    How does the pattern in sea surface temperatures in the North Pacific know about the motion of the Sun about the Solar System’s Barycentre?


    b) both long-term changes in the PDO and long-term deviations in the Earth’s rotation rate
    appear to be synchronized with the Solar Inertial Motion (SIM) about the Barycentre of the
    Solar System.

    The Planetary Lunar Climate Connection
    Page 19, Figure 11

    Can we predict when the PDO will turn positive again?

    The synchronization between the Solar Inertial Motion (SIM) and the Lunar Orbit

  3. tallbloke says:

    I wonder if the ‘big tide’ in 1974 has anything to do with the reversal in LOD trend around that time. And indeed ‘the great climate shift’ of 1976.

    Fascinating findings Ian.

  4. Paul Vaughan says:

    There’s no regional climate index that does not relate to LOD.

    In a crude oversimplification (in an attempt to speed up communication), regional contributions a, b, c, d, & e have some degree of freedom from one another but are constrained globally by a+b+c+d+e = global constraint.

    Tomas Milanovic explained this patiently at Climate Etc. I made an introductory attempt to loosely convey it visually to a lay audience using observational data (WUWT article on interannual variations). We both failed to simplify a narrative that could reach more than a tiny (if even that) fraction of a general audience. If there’s a way to teach it efficiently, it evades me for now.

    What I’m doing in the following is simply peeling off the interannual & inter-regional degrees of freedom & spatiotemporal phase mixing to see what’s left as a global decadal constraint:

    1. terrestrial polar motion (wobble) signal in decadal-extent cross-ENSO annual-grain LOD (interhemispheric angular momentum imbalance) anomalies (from decadal Gaussian climatology)

    2. solar signal in decadal-extent semi-annual-grain LOD (hemispherically alternating mid-latitude westerly wind jet) anomalies (from decadal Gaussian climatology)

    There are dozens of ways to isolate these patterns. Pattern stability is robust across methods. (This is totally unsurprising given the beautifully tight constraints afforded by LCAM, CLT, & TWR.)

    Jean Dickey (NASA JPL) published the same patterns in a different format in 1997.

    There are liberating exploratory implications on several fronts.

    LCAM = Law of Conservation of Angular Momentum
    CLT = Central Limit Theorem
    TWR = thermal wind relation