Is The Earth's Rotation Changing?

Roland Piquepaille writes "We all know about the current controversies associated with the ozone layer or the global warming phenomenon. Now, the NASA's Earth Science Enterprise (ESE) is warning us that atmospheric changes or El Niño events can affect the Earth's rotation. During El Niño years, for example, the rotation of the Earth may slow ever so slightly because of stronger winds, increasing the length of a day by a fraction of a millisecond. David A. Salstein, an atmospheric scientist from Atmospheric and Environmental Research, Inc., led a recent study about this possible effect. Salstein looked at meteorological and astronomical measurements from different sources and found they were in good agreement. Check this column for a synthesis. For technical explanations, images and animations, please read this NASA paper, Changes in the Earth's rotation are in the wind."

Oh great,

[Quila]

Yet another thing the greens can attach to (supposedly man-made) global warming.

This is news?

[hottoh]

Physics tells me that a gas and a fluid have many similar characteristics. The most significant difference of course is a liquid is approximately 1000 times more dense than a the atmosphere.

Consequently the oceans slow the rotational period of the earth. I read about the physics of the tides twenty some years ago. The physics was clear then.

Would be only short term

[BongoBonga]

It seems like a reasonable enough argument that the rotation period of the earth would change during an el nino period. But once this the el nino effect had ended the rotation of the earth would have to return to normal, so any effect that might occur would be only short term. Also due to the large difference in the mass of the solid earth and the earths atmosphere, the change in the earths period of rotaion would be so small as to be unmeasurable and therefore unimportant.

Short Term?

[Acidic_Diarrhea]

When you're dealing in matters of planets, short-term is a thousand years.

And what are you talking about with your statement about the change being "unmeasurable"? The point of the article is that it is being measured.

since 1900

[peter303]

Well-known branch of astronomy called "LOD" or length of day measurements. Changes up to a millisecond or so each year. Atomic clocks and satellites allowed microsecond precision now. Weather, magnetic storms, earthquakes, ocean currents all tought to affect LOD.

This story is a plant advertising a movie

[goombah99]

This smells a lot like a planted science article advertising the movie The Core [thecoremovie.com] ( opening march 28) .

Just like the last one planted by the same folks. Who? its a promo for the movie "the CORE" about what? the slowing rotation of the earth's core (caused by a secret weapon project).

the last one was also in slash dot too. its was on drilling to the earths core with advanced materials. (sorry I cant locate the slashdot article right now, though I did see the last one about the mars core [slashdot.org]

in that case the movie distibuter's publicity folks were using real science and real information. They were just responible for planting news articles about it strategically. this smells the same, and the timing makes it clear.

Main topic.

[Fastlane]

It seems everyone here is missing the main topic. (And not just the ones modded Offtopic)
The main cause of the earth's rotation slowing _during EL Nino years_ is the change in the angular momentum of the earth. This means, that as some point, the angular momentum will change BACK!! Hence, CONSERVATION of momentum. The net effect in the long run is no change in the earth's rotational period due to this phenomenon.
However, it has been a well known fact that the earth's day will gradually grow longer. One of the causes of this is the earth becoming tidally locked with the moon, the way the moon is now. It's just a function of relative gravitational force.
And offtopic: The geologic record does indicate the magnetic poles reversing every 10k-12k years. You'll have to research the 'why' on your own though. I only remember from my astronomy classes that it does...

The truth is out there, but the server is down or not responding.

This is not news...

[Ramsés Morales]

If I recall correctly, earth rotation, in the beginning, was just 12 hours, and it's been slowing down mainly due to the tides.

Karma to burn, baby

[Quila]

It appears the link between warming and rotation is pretty good. What is not good is the link between man's action and what appears to be part of the Earth's normal warming and cooling cycles.

Besides, I thought we were to all have died from Global Cooling by now, at least that was what they were saying in the 1970s. How did cooling switch to warming so fast?

I'm surprised no one else thought of this yet...

[alchemist68]

The slowing rotation may also be affected by a change in the Earth's center of gravity. I recall from my calculus based physics class that if the mass of a rotating object is translated from near the center of rotation further away from that center of rotation, an object slows its rotation. This is known as conservatin of angular momentum. Taking all that crude oil from the ground and burning it in our cars over 100 years has shifted some the Earth's mass from below the surface to the atmosphere. And since there was a phase change in moving this material from the ground to the atmosphere, this should make the effect a little more noticable as the CO2 can be further displaced high in the atmosphere. This may contribute to a thousands of a second decrease in the Earth's rotation. Of course, I'm sure this guy also didn't take into account the umpteen million metric tonnes of star dust slamming into the Earth every year, adding mass to the Earth and further decreasing the rate of rotation.

I don't know, I just a geeky chemist with wild ideas.

Re:But what about the moon?

[SubliminalLove]

You've got your basic laws of thermodynamics down pat, my friend, but you're forgetting one thing. Conservation of energy is true in any closed system, but the winds of the Earth are fueled by sunlight. That means the energy comes in as heat, then turns into kinetic energy, so it would actually be possible for the effect to change the speed of the earth's rotation.

Now, why milliseconds a year are important? I couldn't tell you; if this effect got bad enough to have a noticeable impact on any of us, the planet would be uninhabitable. It would take a lot of wind to speed up a planet.

Let's pay attention to the important news here, people. Like, will Sony ship a reasonable number of PS3s?

~SL

Accuracy & Precision

[slipstick]

These guys seem to have forgotten that scientific data has two requirements. Accuracy and precision. Since they refuse to show the precision of their measurements, any statement as to their accuracy is right out the window.

Give us those error bars guys, than we can talk.

hmm..

[C21]

for that matter what about the minute changes that our orbit undergoes when we acquire more space dust (pounds and pounds a day) or send people/spacecraft into space. Losing or gaining mass effects orbit, too, in addition to meterological events.

Slow down due to space dust

[Vietomatic]

Another important factor that contributes to the slowing down of Earth's rotation is definitely space dust. Every year, the Earth gains at least 30 million kilograms of space dust. This added mass will indeed reduce the time it takes for the Earth to complete a rotation by fraction of a second.

We need a space vacuum to suck up all of the dust before it gets here...wait a minute, space is already a vacuum!

That was scientific research

[Quila]

And in the 1970s it said we were all going to freeze.

Just because you don't want something to be true doesn't mean that it isn't true

And the reverse too. Of course they want global warming to be true, as they've based their whole being on that hypothesis. Disproving global warming to a green would be like disproving God to a Christian; both would result in a crushing blow to the psyche and massive denial.

Panic sells, and simply saying that the Earth has warming and cooling cycles doesn't. A lot of people have a lot to loose if it turns out the latest catastrophe fad is as valid as its predecessors.

Relationships and observations

[Quila]

I know all of that. What I want is something to show a causal versus casual relationship, and for someone to take into account the accuracy of measurements prior to the last 100 years.

Young-Earth creationists also use inaccurate historical measurements (in this case, the speed of light) to bolster their argument.

I would also like someone to explain to me why all the pre-1970 data used to show a cooling trend, and now it's a warming trend.

Basically, there has been too much chicken-little science throughout the ages for me to hitch onto a catastrophism theory this young.

Re:That was scientific research

[nomadic]

Heh, nobody's disputing that the earth has warming and cooling cycles. They're disputing the idiotic conclusion that because it does, that's the only possible explanation for global warming.

Let's turn it into an appropriate analogy and you'll immediately see the flaw:

People die of old age. Therefore, if someone just died, they died of old age.

Now see the problem? Murder, suicide, accident, none of those things exist in such a universe.

Of course they want global warming to be true, as they've based their whole being on that hypothesis.

Riiiight, I really want there to be flooding, disease, famine, and drought in my lifetime. That would be super.

Re:Karma to burn, baby

[gowen]

I thought we were to all have died from Global Cooling by now, at least that was what they were saying in the 1970s. How did cooling switch to warming so fast?

You did think that. Allow me to correct your (extremely popular) misconception. http://www.wmc.care4free.net/sci/iceage/ Executive Summary : No peer reviewed journal printed a single paper predicting an anthropmorphic global iceage. Not one. Anywhere. Really.