From the University of Liverpool , something I found interesting because a few years ago, former State Climatologist Jame Goodridge said he saw correlations between length of day and other atmospheric processes.
Research reveals Earth’s core affects length of day
Research at the University of Liverpool has found that variations in the length of day over periods of between one and 10 years are caused by processes in the Earth’s core.
The Earth rotates once per day, but the length of this day varies. A yeas, 300million years ago, lasted about 450 days and a day would last about 21 hours. As a result of the slowing down of the Earth’s rotation the length of day has increased.
The rotation of the earth on its axis, however, is affected by a number of other factors – for example, the force of the wind against mountain ranges changes the length of the day by plus or minus a millisecond over a period of a year.
Professor Richard Holme, from the School of Environmental Sciences, studied the variations and fluctuations in the length of day over a one to 10 year period between 1962 and 2012. The study took account of the effects on the Earth’s rotation of atmospheric and oceanic processes to produce a model of the variations in the length of day on time scales longer than a year.
Professor Holme said: “The model shows well-known variations on decadal time scales, but importantly resolves changes over periods between one and 10 years. Previously these changes were poorly characterised; the study shows they can be explained by just two key signals, a steady 5.9 year oscillation and episodic jumps which occur at the same time as abrupt changes in the Earth’s magnetic field, generated in the Earth’s core.
He added: “This study changes fundamentally our understanding of short-period dynamics of the Earth’s fluid core. It leads us to conclude that the Earth’s lower mantle, which sits above the Earth’s outer core, is a poor conductor of electricity giving us new insight into the chemistry and mineralogy of the Earth’s deep interior.”
The research was conducted in partnership with the Université Paris Diderot and is published in Nature.
Gosh, that almost looks like a temperature graph with the AMO. Please, please, please, do not tell that to Mann. He will blame ADLC (Anthro Day Length Change) on CO2 and want to ban fossil fuels so that one side of the earth does not stay faced toward the sun at all times.
Imagine, only 7 hours of sleep a day. It would kill me.
‘A yeas’, needs fixing
delete me afer..
I believe that anything that ‘plays’ with the Earth, Moon, Sun gravity fields effects on the others causes a modulation ofn the Climate that we see. Gravity is the way that energy is interchanged between non-radiating bodies in an orbital paths. That very slow release of ‘frictional energy’ on the other body that acts as a ‘spring’ to allow the other to get away.
I mean, what other way is there to do it? Interesting?
It would be interesting to see if there is any relationship between the 60 year LOD cycle and the 60 year PDO cycle. Could ENSO events be due to ‘slopping’ Kelvin waves as well as winds?
FAO has used LOD – or at least a model with 55 yr cycles – for temperature (and fish catch) forecasts.
ftp://ftp.fao.org/docrep/fao/005/y2787e/y2787e08.pdf
In addition to Goodridge, Courtillot and Morner also have papers on the climate connection to length of day:
http://hockeyschtick.blogspot.com/2010/08/paper-more-ways-sun-influences-climate.html
http://hockeyschtick.blogspot.com/2011/03/geophysicist-explains-how-sun-controls.html
http://hockeyschtick.blogspot.com/2011/05/geophysicist-dr-nils-axel-morner.html
Needs editing, incomprehensible:
A yeas, 300million years ago,
Ian W says:
July 11, 2013 at 3:43 pm
“It would be interesting to see if there is any relationship between the 60 year LOD cycle and the 60 year PDO cycle. Could ENSO events be due to ‘slopping’ Kelvin waves as well as winds?”
I thin you may have to account for what looks like a 24 year cycle as well as 60 years.
That would at least split the enregy left to be distributed into more sensible RMS values.
http://i1291.photobucket.com/albums/b550/RichardLH/UAH-Comparisonofcascadedlowpassfilteroutputmonthsrunningaverage_zpsf1883e44.png
Why is the Earth’s rotation and orbital period slowing (over billions of years of course)?
Is it due to work between Earth and Solar magnetic fields? … Lief?
Richard III July 11, 2013 at 3:42 pm
I mean, what other way is there to do it? Interesting?
The interaction of magnetic fields
“yeas” should be “year”
“The rotation of the earth on its axis, however, is affected by a number of other factors – for example, the force of the wind against mountain ranges changes the length of the day by plus or minus a millisecond over a period of a year.”
*
The force of wind? This sounds to me a bit like blowing on your own sail or trying to hold up a swing with your own hands. A bunch of you who are more learned than I might jump on my conclusion there, and so be it, I won’t argue back. Another point, though, is that while mountain ranges seem big to tiny little creatures like us, on scale with the planet they are hardly there at all.
It doesn’t ring true to me that the wind can push the planet around, even by minute amounts.
Uh, the Y scale here is in milliseconds, to the human eye it might as well be hours. In other words there isn’t much variation in the length of the day, but this chart make it look like there is. Most of this chart is below average so what does average really mean here? Personally I like have longer days, I can get a lot more done in an extra 4 milliseconds or so. This is another example of research money well spent, if we can figure out a way to get 5 more milliseconds out of the day that would really be something.
Robert of Ottawa says:
July 11, 2013 at 3:58 pm
Richard III July 11, 2013 at 3:42 pm
That’s not be . Take that poster down!
“The interaction of magnetic fields”.
Indeed. But the magnitudes of energy available are very different. I would call gravity first.
I would have thought tidal forces would have a greater impact than wind against mountains, but I’ve guess I learned something today. 🙂
Tom Trevor says:
July 11, 2013 at 4:01 pm
“Uh, the Y scale here is in milliseconds, to the human eye it might as well be hours.”
So you consider that styudying the minute oscilations, that show up here as variations in the msecs, are in now way connected to that beautfull dance that the orbits show?
Most of the change in the length of day is due to the transfer of angular momentum from the earth to the moon due to tidal forces. The moon is accelerated by the tidal bulges into a higher orbit, at the same time the earth’s rotation slows by an equivalent amount to balance the energy. I would expect that settling of heavier elements (Ni and Fe) into the core would tend to counteract the decrease in rotation rate by a lesser amount.
I am of course speaking of long-term changes, over the full history of the earth, not short term changes discussed in the article above.
Unfortunately, I believe that Anthony has chosen the wrong horse in this case.
http://astroclimateconnection.blogspot.com.au/2013/02/do-you-think-that-moon-might-have.html
This parametre is carefully studied by a number of different international organizations including the International Earth Rotation and Reference Systems Service, the Special Bureau for the Atmosphere and the Earth Orientation Centre.
Yes, the length of day actually changes and this can be caused by the wind-drag (very short-term), ocean-drag (short-term), moon-gravity-drag (millions of years), core and mantle rotation processes (medium-term), and the gravity from the other planets in the solar system (long-term).
http://www.iers.org/nn_10896/IERS/EN/IERSHome/home.html?__nnn=true
http://www.aer.com/science-research/earth/earth-mass-and-rotation/special-bureau-atmosphere
http://hpiers.obspm.fr/eop-pc/index.php?index=mission&lang=en
Bill Illis says:
July 11, 2013 at 4:38 pm
“this can be caused by the wind-drag (very short-term), ocean-drag (short-term), moon-gravity-drag (millions of years), core and mantle rotation processes (medium-term), and the gravity from the other planets in the solar system (long-term).”
I think that the ‘frictional effects’ of Lunar/Earth interaction are underestimated. How the Moon’s gravity ‘plays’ with our Climate by that effect and thus ‘gains’more energy to get away.
This cannot possibly be so … ask any old timer (me too) … the days seem to be rocketing by much faster nowadays.
Ahhhh, length of day affected by man-made greenhouse gases.
Here is the peer reviewed literature. As I said before, we must insist on the science. 🙂 Haaaa haaa.
Earth’s rotation to slow down
Earth’s rotation to speed up
Interesting concentration on short-term variations. However, over longer periods (millions of years) the earth-moon tidal system is more determinative. The moon is observed to move to a higher, more energetic, orbit (about 1 inch/year) as a result of the earth’s rotation/tidal forces. That energy is subtracted from the earth’s rotation, therefore it slows down.
Incidentally, that presents a dilemma over a long period. Assuming that Newton’s Laws remain constant, and that the oceans are relatively unchanged, over billions of years, you can back the earth-moon system up. As the moon gets closer, the tidal forces get larger and the process speeds up. Accordingly, about one and a half billion years ago the moon was close enough to cause tides higher than the continental mountains, and the earth is spinning like a top. What’s wrong with this picture?