Length of day correlated to cosmic rays and sunspots

From techno-science.net This tip came in on our tip & notes page, and at first I was quite surprised because I could not see a possible mechanism for it. Then as I read the translation (from French) it started to make more sense. I’ll point out my friend Jim Goodridge published an essay on WUWT about correlation of the PDO and  rainfall with LOD: California Climate, PDO, LOD, and Sunspot Departure

Here’s the graph from the current article of interest:

And here’s some excerpts describing possible mechanisms:

Some authors, notably Bourget et al (1992), had begun to reveal correlations between solar activity and the length of day, and more recently, Abarca del Rio et al (2003) and Winkelnkemper (2008) in his thesis noted that the amplitude of the component semi-annual (6 months period) of the length of day and atmospheric angular momentum were anti-correlated with changes in the same period of the ” solar constant (the solar constant expresses the amount of solar energy (actually a lighting power) which would be one …) “.

What could be the link between certain changes in day length, the zonal winds and solar activity? To help answer this question, The Mouël and colleagues analyzed a series of 48 years (from 1962 to 2009) of daily measurements of the length of day, the service provided by the International Earth Rotation and systems reference located at the Observatoire de Paris. They have extracted the component of period 6 months and showed significant variations in the amplitude of this component, about 30%, they compared the one hand the number of sunspots (the Wolf number, a traditional indicator of solar activity measured for several centuries) and also the flux of galactic cosmic ray.

The authors show a good correlation between these three parameters, more precisely (Figure), it is the evolution of cosmic rays and the amplitude of the semi-annual day length are correlated (correlation coefficient the order of 0.7), and are in phase. The correlation is improved when we remove the curve (In geometry, the word curve or curved line designates certain subsets of the plan, the usual space. ,…) example of day length linear trend which could be related to phenomena occurring in the nucleus. It is established also that variations in cosmic rays are out of phase with sunspots and shifted about a year (this is attributed to the mechanism of modulation of galactic cosmic rays by the solar wind (solar wind is a stream plasma consisting essentially of ions and electrons are ejected from the high …) and its magnetic field).

How the speed of rotation of the Earth can it be sensitive to the modulation of cosmic rays?

The answer is in the system of winds. Those who contribute most to the seasonal variations of angular momentum are the winds of relatively low altitude (Altitude is the vertical elevation of a place or object relative to a baseline.) below 30km . Taking an average over a year (A year is a unit expressing the duration of time between two occurrences of an event linked to the revolution …), the difference between radiation (Radiation is energy transfer under form of waves or particles, which can occur by radiation …) received from the Sun ((weight percent)) and one that is emitted by the Earth outward into the great length of wave (A wave is the propagation of a disturbance occurring on its passage a reversible variation of properties …) (IR) is positive towards the equator and negative beyond 40 degrees latitude (Latitude is an angular value, expression north-south position of a point on Earth (or another …).

This latitude gradient must be balanced by a flow of energy (in the common sense energy means anything that allows a work, making the heat, …) from the equator to the poles: the transportation (transport, from the Latin trans, beyond, and portare wearing is wearing something, or someone one, a place …) is provided by the Southern movements (that is to say along the geographic meridians) of the atmosphere, averaged in longitude (Longitude is an angular value, expressing the position east-west from a point on Earth (or another …), and eddies. The zonal winds are the result of this transport because of conservation of angular momentum: going to the poles is approached the axis of rotation of the Earth and changes in this distance must be compensated by changes in speed. The seasonal variations in insolation lead to variations of the same period of the carriage along the meridians and, from there, the mean zonal winds.

There is another route by which clouds can be affected: the atmosphere is indeed penetrated by a vertical electric current of a few nano-Ampere per square meter (the meter (the meter (symbol m, the Greek metron, measure) is the basic unit of length in the International System. … It is defined) square (a square is a regular polygon with four sides is a quadrilateral that is both a rectangle (it a. ..) ( symbol m) is the unit area of the international system.), which fluctuates with the ionospheric currents and therefore the solar activity. These vertical currents electrically charged clouds and, again, change their micro-physical state. Both mechanisms can indeed co-exist. What characterizes them is that those variations induced by solar activity is measured in tenths of a percent and not in parts per thousand. That’s where the important niche amplification (We are talking about force amplifier for a whole range of systems that amplify the efforts: mechanics ,…) of the phenomenon.

Thus, the Earth (specifically the mantle), the rotation is accelerated or slowed according to the fluctuations of cosmic rays under the influence of solar activity through the zonal winds, provide a wonderful device integration variations in atmospheric angular momentum and zonal wind circulation that it is difficult to measure directly.

Full article and translation here

h/t to WUWT reader Steward

What could be the link between certain changes in day length, the zonal winds and solar activity?

Pour tenter de répondre à cette question, Le Mouël et ses collègues ont analysé une série de 48 années (de 1962 à 2009) de mesures journalières de la longueur du jour, fournies par le service international de la rotation de la Terre et des systèmes de référence situé à l’Observatoire de Paris. To help answer this question, The Mouël and colleagues analyzed a series of 48 years (from 1962 to 2009) of daily measurements of the length of day, the service provided by the International Earth Rotation and systems reference located at the Observatoire de Paris. Ils en ont extrait la composante de période 6 mois et ont mis en évidence de fortes variations de l’amplitude de cette composante, de l’ordre de 30%, qu’ils ont comparé d’une part au nombre de taches solaires (le nombre de Wolf, un indicateur traditionnel de l’activité solaire mesuré depuis plusieurs siècles) et d’autre part au flux de rayon cosmiques galactiques. They have extracted the component of period 6 months and showed significant variations in the amplitude of this component, about 30%, they compared the one hand the number of sunspots (the Wolf number, a traditional indicator of solar activity measured for several centuries) and also the flux of galactic cosmic ray.

Les auteurs mettent en évidence une bonne corrélation entre ces trois paramètres, plus précisément (Figure), ce sont les évolutions des rayons cosmiques et de l’amplitude de la composante semi-annuelle de la longueur du jour qui sont corrélées (coefficient de corrélation de l’ordre de 0,7), et qui sont en phase. The authors show a good correlation between these three parameters, more precisely (Figure), it is the evolution of cosmic rays and the amplitude of the semi-annual day length are correlated (correlation coefficient the order of 0.7), and are in phase. La corrélation est améliorée quand on retire à la courbe de la longueur du jour une tendance linéaire, qui pourrait être liée à des phénomènes se produisant dans le noyau. The correlation is improved when we remove the curve (In geometry, the word curve or curved line designates certain subsets of the plan, the usual space. ,…) example of day length linear trend which could be related to phenomena occurring in the nucleus. Il est établi par ailleurs que les variations des rayons cosmiques sont en opposition de phase avec les taches solaires et décalées d’environ un an (ceci est attribué au mécanisme de modulation des rayons cosmiques galactiques par le vent solaire et son champ magnétique). It is established also that variations in cosmic rays are out of phase with sunspots and shifted about a year (this is attributed to the mechanism of modulation of galactic cosmic rays by the solar wind (solar wind is a stream plasma consisting essentially of ions and electrons are ejected from the high …) and its magnetic field).

Comment la vitesse de rotation de la Terre peut-elle donc être sensible à la modulation des rayons cosmiques ? How the speed of rotation of the Earth can it be sensitive to the modulation of cosmic rays?

La réponse est dans le système des vents. The answer is in the system of winds. Ceux qui contribuent le plus aux variations saisonnières du moment angulaire sont les vents de relativement basse altitude , en dessous de 30km. Those who contribute most to the seasonal variations of angular momentum are the winds of relatively low altitude (Altitude is the vertical elevation of a place or object relative to a baseline.) below 30km . Prise en moyenne sur une année , la différence entre le rayonnement reçu du Soleil et celui qui est réémis par la Terre vers l’extérieur dans les grandes longueur d’ onde (infra-rouge) est positif vers l’équateur et négatif au delà de 40° de latitude . Ce gradient en latitude doit être équilibré par un flux d’ énergie de l’équateur vers les pôles: ce transport est assuré par les mouvements méridionaux (c’est-à-dire le long des méridiens géographiques) de l’atmosphère, moyennés en longitude , et les tourbillons. Les vents zonaux sont la conséquence de ce transport à cause de la conservation du moment angulaire: en allant vers les pôles on se rapproche de l’axe de rotation de la Terre et les changements de cette distance doivent être compensés par des changements de la vitesse. Les variations saisonnières d’insolation entraînent des variations de même période du transport le long des méridiens et, partant de là, de la moyenne des vents zonaux. Taking an average over a year (A year is a unit expressing the duration of time between two occurrences of an event linked to the revolution …), the difference between radiation (Radiation is energy transfer under form of waves or particles, which can occur by radiation …) received from the Sun ((weight percent)) and one that is emitted by the Earth outward into the great length of wave (A wave is the propagation of a disturbance occurring on its passage a reversible variation of properties …) (IR) is positive towards the equator and negative beyond 40 degrees latitude (Latitude is an angular value, expression north-south position of a point on Earth (or another …). This latitude gradient must be balanced by a flow of energy (in the common sense energy means anything that allows a work, making the heat, …) from the equator to the poles: the transportation (transport, from the Latin trans, beyond, and portare wearing is wearing something, or someone one, a place …) is provided by the Southern movements (that is to say along the geographic meridians) of the atmosphere, averaged in longitude (Longitude is an angular value, expressing the position east-west from a point on Earth (or another …), and eddies. The zonal winds are the result of this transport because of conservation of angular momentum: going to the poles is approached the axis of rotation of the Earth and changes in this distance must be compensated by changes in speed. The seasonal variations in insolation lead to variations of the same period of the carriage along the meridians and, from there, the mean zonal winds.

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Doug in Seattle

The correlation is interesting, the proposed mechanism too, but the translation sucks – whats up with the parentheses?

Interesting.
Last year, I also found a correlation between length of day and the motion of the sun’s equatorial plane with respect to the centre of mass of the solar system, or solar system barycentre
http://tallbloke.wordpress.com/2009/11/29/planetary-solar-climate-connection-found/
The evidence supporting the hypothesis that the motion of the planets affects levels of solar activity is getting stronger all the time. Those who have attacked, insulted and denigrated the people working on this will eventually be forced to eat their words.

Scarlet Pumpernickel

Sound of the sun, hey look, it changes! I thought it was static and had no effect on earth
http://www.nsf.gov/discoveries/disc_videos.jsp?cntn_id=117729&media_id=68449&org=NSF

Julian Braggins

At last a reasoned explanation for something that cropped upon Dr Pielke senior’s website a few years ago when comments were allowed, that is , the anti-correlation between sunspots and LOD.
Another point for the “It’s The Sun S—-d”

tallbloke says:
October 4, 2010 at 12:17 am
The evidence supporting the hypothesis that the motion of the planets affects levels of solar activity is getting stronger all the time. Those who have attacked, insulted and denigrated the people working on this will eventually be forced to eat their words.

That day is coming closer Rog 🙂

Reference

Long Term Variations in the Length of Day and Climatic Change. Lambeck, K & Cazenave, A, Geophys. J. R. astr. Soc. (1976) 46, 555-573
http://people.rses.anu.edu.au/lambeck_k/pdf/37.pdf

Al these factors have one common factor – two major planets Jupiter and Saturn.
Electro-magnetic feedback (via magnetospheres interaction) as a modulator of the sunspot cycle and the Earth’s magnetosphere and its magnetic field, and possibly additional gravitational pull on the Earth’s rotation.
http://www.vukcevic.talktalk.net/LFC11.htm
http://www.vukcevic.talktalk.net/LFC9.htm
It makes sense that if there is a number of LOD correlations, then in final analysis, all must lead to the same source.

Here is LOD correlation with the Earth’s magnetic 1900-2000, and the Earth’s magnetic field and sunspot cycle 1600-2000.
http://www.vukcevic.talktalk.net/LOD-GMF.htm

Nylo

If I understand this well, the more cosmic rays, the bigger the difference of the length of day between summer and winter (or spring and fall, whatever). This seems good enough to demonstrate that cosmic rays have some kind of real, noticeable effect in the atmosphere. Good enough to start paying a lot more attention to them. But still it doesn’t prove whether that effect is supposed to bring global warming, global cooling or neither of them.
Any news from the CLOUD project?

It took me a while to convince myself you were talking about the speed of rotation of the earth and not the “daylight” hours (which clearly would be affected by clouds and so easily affected by cosmic rays).
Wow!!
So basically the earth itself is being affected by a force related to sunspots.
… but not the climate!!!

Nylo says:
October 4, 2010 at 1:26 am
Any news from the CLOUD project?
Latest report from CERN is inconclusive:
In summary, the exploratory measurements made with a pilot CLOUD experiment at the CERN Proton Synchrotron have validated the basic concept of the experiment, provided valuable technical input for the CLOUD design and instrumentation, and provided, in some of the experiments, suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles from trace sulphuric acid vapour at typical atmospheric concentrations.
http://www.atmos-chem-phys.net/10/1635/2010/acp-10-1635-2010.pdf

Mike McMillan

So are we doomed or what? Those definitions did more to muddy the story than elucidate it.
Cosmic rays affect clouds, which affect insolation, which affects the winds, which affect the rotation, n’est-ce pas?
Looking at the article, I gather the cut and paste between it and WordPress collected the definitions in addition to the article. Perhaps if we excised all the stuff in parentheses it might read better. And untranslate the author’s name from “The Mouël ” back to “Le Mouël .”
I’d volunteer, but I already filled my translation dance card with a Montréal bi-lingual web site last year.

Mike McMillan

The length of days varies by a few milliseconds over periods of several months, to put things in better perspective.
Also, “nucleus” better translates as “core.”
…solar activity is measured in tenths of a percent and not in parts per thousand
Tenths of a percent IS parts per thousand.
I quit. I’m moving on to Sea Ice Update.

Roger Longstaff

I am trying to get my head round this – is the hypothesis that cosmic rays have an effect on wind speed, which in turn has an effect on the angular momentum of the Earth? Given the many orders of magnitude difference between the masses of the Earth and the atmosphere I can not understand this.
Also, the ephemeris of the other planets in the solar system are well known, so probably no correlation there.
If the data are correct, surely this is more likely a magnetic effect?
A very interesting subject – it will be interesting to see the ideas of others.

Stephen Wilde

Now, could someone suggest what effect all this might have on the upward energy flux when the sun is more active and when it is less active ?
It appears that when the sun is more active the troposphere and thermosphere both warm up but the stratosphere and mesosphere both cool down.
Any mechanism that deals with that observation will fit nicely into my New Climate Model.

Dave Springer

The earth’s rotation, or at least the crust in relative to the mantle, accelerates and decelerates?
It seems like that would cause stress on the crust and there should be some cyclical evidence of it at plate boundaries like variation in volcano and earthquake activity.
I’d suspect measurement errors first and relativistic effects next. There’s probably some common causal connection between this and the anomalies in radioactive decay rates that appear to be related to the sun as well.

Disputin

I read somewhere that variations in day length were attributed to differences in the distribution of snow and ice through seasonal changes, which might just provide a link with solar activity if there is some effect there. I still have difficulty thinking that atmospheric winds are going to have any noticeable effect on a bloody great flywheel like the Earth, though. All very puzzling.

Here as an alternative view:
The Earth’s magnetism is due to the electric currents in the core. Generation of the field requires energy and this is supplied by the Earth’s rotation, i.e. stronger the field results in greater LOD (strong field takes more energy, slowing down the rotation, increasing LOD).
http://www.vukcevic.talktalk.net/LOD-GMF.htm
Reason for change in the strength of magnetic field are currents in the ionosphere due to solar activity.
http://www.vukcevic.talktalk.net/Image1.gif
Ionosphere currents induce strong electric currents in the Earth’s lithosphere, which counteract the effect of the core currents and so reducing breaking effect of the main magnetic field (faster rotation), resulting in reduced LOD
Summary: stronger solar activity, stronger ionosphere currents, stronger lithosphere induced currents suppressing the main magnetic field, reducing magnetic brake on the Earth’s core (weaker field less energy taken out of rotation), faster rotation, reduced LOD.
No cosmic rays, no clouds, no winds required!

Jerry

Tallbloke said
The evidence supporting the hypothesis that the motion of the planets affects levels of solar activity is getting stronger all the time. Those who have attacked, insulted and denigrated the people working on this will eventually be forced to eat their words.
I simply ask if the rotational period of the earth affects solar activity, or if solar activity affects the rotation of the earth.
That there is correlation is one thing, causation is quite another, and to my mind, the bigger guy always wins – i.e. the Sun is the driving factor

Suzanne

vukcevic says:
October 4, 2010 at 2:41 am
Here as an alternative view:
The Earth’s magnetism is due to the electric currents in the core.
Actually, it’s my understanding that the earth’s magnetism is caused by the generation of electric currents in the earth’s “liquid outer” core.
See: Earth’s magnetic field gathers momentum – May 11, 2010 (excerpt)
http://physicsworld.com/cws/article/news/42580
Physicists in France have linked subtle variations in the length of day with conditions in the Earth’s core – where the Earth’s magnetic field originates. The finding could improve our poor understanding of how the field is generated and why it changes in response to conditions deep within the Earth’s interior.

John

As Jerry says, correlation is not causation – while it might be true that sunspots, cosmic rays, and the earths rotation all display changes which appear to be in synch, this could equally be because they are all being influenced by a still to be confirmed external force.
Isn’t this in line with what Landscheit was saying? I came across his work some years ago and it seemed to make sense, but I remember having my knuckles rapped when I mentioned him on Steve McIntyre’s blog.
http://bourabai.narod.ru/landscheidt/new-e.htm

simpleseekeraftertruth

vukcevic says:
October 4, 2010 at 2:41 am
“Here as an alternative view:”
I don’t see how a reduction in a breaking force can cause an acceleration. There would have to be some driver in place at the same time with the driver and/or brake varying in intensity.

What characterizes them is that those variations induced by solar activity is measured in tenths of a percent and not in parts per thousand.
A tenth of a percent is a part per thousand….
It seems also that the usual suspects are here singing their favorite tunes.

simpleseekeraftertruth

Braking force.

Suzanne says: October 4, 2010 at 3:20 am
…………
You are absolutely correct, I was not sufficiently precise. It is even possible that induced electric currents do reach as far down as location of the source of the Earth’s field, the liquid outer core.
simpleseekeraftertruth says: October 4, 2010 at 3:28 am
……….
Earth’s rotation provides energy for generating magnetic field, reduce the magnetic field load by inducing currents, less energy taken out of globe’s ‘momentum’, than it simply follows angular velocity (translated into rotation rate) has to increase. This is due to the fact that generation of the Earth’s magnetic field is a dynamic process, not a static source of magnetism as a bar-magnet is.

anna v

Mike Haseler says:
October 4, 2010 at 1:27 am
So basically the earth itself is being affected by a force related to sunspots.
Better say “correlated”, and add “correlation is not causation”.
A simple example : As I walk down the street on a moonlit night the moon appears and disappears as I pass the shadow of the trees. Am I affecting the motion of the moon?
Here we have a demonstration of the conservation of the angular momentum of the earth imposed by the complex motions of the atmosphere ( and I would guess the oceans, but the article has sort of excluded them, though they are a lot denser than the atmosphere). The complex motions of the earth’s currents that require angular momentum balance are seen to be correlated with cosmic ray cycles which cosmic rays are correlated to the sunspot cycles. So far so good. It does not mean that the angular momentum of the earth affects the sunspot cycles! Cosmic rays may affect the currents of the earth’s fluids by a mechanism a la Svensmark, or …. whatever hypothesis. The tail does not wag the dog.

anna v
Stanislav Lem

In the same volume, of GRL appears another ‘fun’ article,aka how to jump the global warming band wagon, classical example of how to get published including ‘global warming’ in the articles’ title. Its premises are pretty hilarious,
GEOPHYSICAL RESEARCH LETTERS, VOL. 37, L15703, 5 PP., 2010
doi:10.1029/2010GL043985
Biophysical feedbacks between the Pleistocene megafauna extinction and climate: The first human-induced global warming?
Christopher E. Doughty
Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
Adam Wolf
Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
Christopher B. Field
Department of Global Ecology, Carnegie Institution for Science, Stanford, California, USA
A large increase in Betula during a narrow 1000 year window, ∼13,800 years before present (YBP) in Alaska and Yukon corresponded in time with the extinction of mammoths and the arrival of humans. Pollen data indicate the increase in Betula during this time was widespread across Siberia and Beringia. We hypothesize that Betula increased due to a combination of a warming climate and reduced herbivory following the extinction of the Pleistocene mega herbivores. The rapid increase in Betula modified land surface albedo which climate-model simulations indicate would cause an average net warming of ∼0.021°C per percent increase in high latitude (53–73°N) Betula cover. We hypothesize that the extinction of mammoths increased Betula cover, which would have warmed Siberia and Beringia by on average 0.2°C, but regionally by up to 1°C. If humans were partially responsible for the extinction of the mammoths, then human influences on global climate predate the origin of agriculture.

Leif Svalgaard says: October 4, 2010 at 4:03 am
It seems also that the usual suspects are here singing their favorite tunes.
This blog is not in the business of ‘consensus science’ , but if it was, you would be outvoted if you have put an opposite view, but as yet you have not, sure sign of ‘science is not settled’.

Doug in Seattle says:
October 3, 2010 at 11:53 pm
> The correlation is interesting, the proposed mechanism too, but the translation sucks – whats up with the parentheses?
If you go to the original article, all those parenthesized things are the text that would pop up if your mouse “hovers” over the term.
They’re annoying it the original, out of control in the translation!
I started the day with a mild headache, phrases like “the difference between radiation … received from the Sun … and one that is emitted by the Earth outward into the great length of wave … (IR)”
—–
Mike McMillan says:
October 4, 2010 at 1:53 am
> Also, “nucleus” better translates as “core.”
I figured that out, but then I couldn’t figure out what was the core.
> “solar activity is measured in tenths of a percent and not in parts per thousand Tenths of a percent IS parts per thousand.
That’s the other reason I went to the original, it says

Ce qui les caractérise, c’est que les variations induites par celles de l’activité solaire se mesurent en dizaines de pour cent et non en partie par millier.

I don’t claim to know French, but I fear in this case the translation is accurate.
> I quit. I’m moving on to Sea Ice Update.
Save a spot for me….

WAM

I would follow Anna V path.
Conservation of angular momentum.
Warmer years -> more leaves on trees -> higher moment of inertia -> lower angular velocity of Earth
And vice versa

anna v says:
October 4, 2010 at 4:32 am
this is an interesting summary:
http://www.jpl.nasa.gov/news/features.cfm?feature=15
Anna V thanks for the link.
Great article!
It confirms what I said above
“The longer patterns in changes of the length of the day can last for decades. “These are caused by processes within Earth’s core,” says Gross. “The core is a fluid. Its motion generates Earth’s magnetic field. Changes in its motion can change the rotation of solid Earth. Observing the magnetic field at the surface gives us an idea of how fluid is moving within the core. These changes in the fluid motion inferred from the magnetic field match the longer period changes we see in the length of the day.”

Both the ions in the atmosphere, and the inductive components in the core/mantle respond in kind to the inductive shifts due to changes in the solar wind flux, in both the LOD and atmospheric angular momentum, so the atmosphere does not have to push upon the land mass to effect the LOD changes as they are being driven in tandem.
Dave Springer says:
October 4, 2010 at 2:22 am
————–Reply; the Boxer day quake and tsunami occurred concurrently with a massive shift in LOD, it is still unproven which was the cause, and which was the effect. The mainstream answer is the movement caused the LOD change, as this mechanism was not known to the general mainstream science back then, and so was the “logical answer”.

Stephen Wilde

All too speculative so far I fear and unlikely to be a large enough forcing agent.
I think I’ll keep looking elsewhere 🙂

Leif Svalgaard says:
October 4, 2010 at 4:03 am
___________Reply; there are three unstoppable things in nature, truth, true love, and an Idea whose time has come.

Carla

vukcevic says:
October 4, 2010 at 2:41 am
“..Reason for change in the strength of magnetic field are currents in the ionosphere due to solar activity..
..No cosmic rays, no clouds, no winds required!”
Mostly I agree. But what about charge imbalance?
Once the cosmic rays increase in the radiation belt and you alter the.. ah…composition of the ionosphere and everything entering below. Increase cloud cover and then produce even more dampening effects within the lower magnetic system.
Howz about that for an oversimplified comment?
After reading the last comments on the Knot in the ribbon at the edge of the solar system “unties,” song pops up .. Dave Clark Five, “Catch Us if You Can.”

It was time to go..

simpleseekeraftertruth

vukcevic says:
October 4, 2010 at 4:08 am
“Earth’s rotation provides energy for generating magnetic field, reduce the magnetic field load by inducing currents, less energy taken out of globe’s ‘momentum’, than it simply follows angular velocity (translated into rotation rate) has to increase. This is due to the fact that generation of the Earth’s magnetic field is a dynamic process, not a static source of magnetism as a bar-magnet is.”
As I understand it, the Earth’s rotation induces the Coreolis effect in the liquid outer core which then organises electric currents that exist within it. The rotation itself does not generate those currents or their magnetic effects. To consider the earth as a dynamo with angular momentum as the driver of flux density requires a loss in energy to space to achieve deceleration and the opposite to achieve acceleration. Unless of course, the flux density requires no rotational energy to vary it with rotation itself being only the catalyst to the phenomenon.

Geoff Sherrington

Then there is the sloshing about of the tides.
“periods in the fortnightly band are always critical in GPS analysis, because they are possibly affected by aliasing due to imperfect reduction of the influence of short period ocean tides and processing characteristics. The reasons for the differences in the other terms mentioned are suspected to be either insufficient modelling of the atmospheric influence or inexact consideration of medium and long period ocean tides in the theoretical model, or even a combination of
both.”
from http://syrte.obspm.fr/journees2007/PDF/s4_11_Englich.pdf
It is not a trivial problem to cause a satellite to make successive passes over the equator, allowing for drag and velocity change, as well as the relative shift of the equator (and its definition) relative to a frame of reference such as a stellar one, or a network of coordinated satellites. This of course has consequences as the uses of satellites become more critical, such as GRACE.

EM Smith has brought up LOD before too.

Carla

vukcevic says:
October 4, 2010 at 2:41 am
One question Vuks, by looking at the field surface can we see where these sporadic weakenings are most likely to occur or are occurring?

I read about an idea, that changing LOD drives the changes in Pacific trade winds, which are responsible for ENSO, which drives other stuff. So the untied knots becoming suddenly tied.

Kiminori Itoh

There is a possibility other than the cosmic rays for the relation between the sunspot number and the LOD.
Sunspot number is a good measure of solar UV which changes about 1% during the 11 year solar cycle. Such a change in the UV intensity is reportedly sufficiently large to cause the tropopause temperature through changing the amount of UV-heating at the stratosphere, and hence, supposedly affects the activity of hurricanes due to the change in the temperature gradient.
If such an effect is possible for solar UV, then it may be also possible that the UV effect is transfered to the global wind circulation through an interaction between the stratosphere and the troposhere.
Once the wind pattern changes, it reflects on Length-of-Day as is known already.

The more we look with an open mind, the more we find, things we don’t know … Science is really fascinating when done right.
How could their not be some sort of interaction of the planets, the sun, on the planets of our solar system?

Carla says: October 4, 2010 at 6:32 am
………
GCR have important effect on heliosphere, and possibly occasionally extreme effect (in case of a supernova explosion – one in 50years in our Galaxy, but only if it is nearby e.g. Maunder min).
Since the Earth’s magnetosphere is stronger than heliosphere, I think that GCR effects on the Earth itself are overrated.
On this one, I think we should rely on data from THEMIS ; sun pumps 650,000Amps electric current into the Arctic, see Fig. 10 in
http://www.nasa.gov/mission_pages/themis/auroras/northern_lights_multi.html
As you can see both of my graphs refer to the Arctic:
http://www.vukcevic.talktalk.net/LOD-GMF.htm
LOD by wind ?; hmm, is just that, ‘straw in the wind’.
I think this is only credible solution .
simpleseekeraftertruth says: October 4, 2010 at 5:59 am
……….
Here, as well as in the above comment, I should rely on the NASA’s science, see article
http://www.jpl.nasa.gov/news/features.cfm?feature=15
(link provided by anna v).

dp

My take-away from this article: The Earth and Solar system generally are a dangerous place. The Earth alone is too complex to operate and didn’t come with any instructions, so we’re making things up as we go. This being a reactive situation, we’re always behind, and sometimes what we do is revealed as being silly when we learn more (burying apples to reduce warts, for example). We should leave before somebody gets hurt.

proxima

>I don’t claim to know French, but I fear in this case the translation is accurate.
It is’nt.
Ce qui les caractérise, c’est que les variations induites par celles de l’activité solaire se mesurent en dizaines de pour cent et non en partie par millier.
“dizaines de pour cent” means “tens of percent”, not “tenth of percent”.
Use “dizièmes” for “tenth”.

Jean Meeus

“Ce qui les caractérise, c’est que les variations induites par celles de l’activité solaire se mesurent en dizaines de pour cent et non en partie par millier. ”
The correct translation is “.. are measured in tens of percents and not in part per
thousand.”
Well, tens of percents is, for instance, 20% or 40%, but what is “part per thousand”? What part? How much? To me that sentence seems strange.

Enneagram

Current Indonesia earthquakes, beginning with the big tsunami in Dec 2004, and 2010 8,9 Chilean earthquake have changed LOD .

Enneagram

Thus, the Earth (specifically the mantle), the rotation is accelerated or slowed according to the fluctuations of cosmic rays under the influence of solar activity through the zonal winds,
“Gone with the wind” ? That’s the Flintstones’ universe explanation.

Enneagram

-Earthquakes cause LOD changes, however earthquakes are electromagnetic phenomena, as evidenced by earthquake lights.
http://www.scribd.com/doc/29238677/Earthquake-3
-Before and during earthquakes gravity acceleration decreases. Changes in the local field may trigger these events.
http://www.scribd.com/doc/38598073/Unified-Field