Gravity Waves: cause of Clear Air Turbulence?

Interesting, but it lacked detail. What initiates a wave? Exactly how do the break? What is the altitude ranges they are found? The reporting seemed to mainly focus on their existence and that they are trying to predict them.
 
John221us said:
Interesting, but it lacked detail. What initiates a wave? Exactly how do the break? What is the altitude ranges they are found? The reporting seemed to mainly focus on their existence and that they are trying to predict them.
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Waves "breaking" as you're used to seeing on the beach is a consequence of the edge of the ocean. The wave speed slows down quite a lot at the edge because it is a function of the depth (for water shallower than the wavelength). As it slows down, it piles up. When it gets big enough, the bottom slows down more than the top and it falls over. If the ocean had a flat bottom all the way to the edge (like a swimming pool or a "perfect" harbor), waves wouldn't break.

All this depends on there being a "surface" and a wave height, and some way to slow it down.

Waves inside a medium can't pile up in the same manner (well, not usually -- you can imagine a frontal surface doing something like that, but cold air and warm air really are the same thing, and one can turn into the other or the two can truly mix, easily). What "piling up" means in this context is that a change in properties gets steeper and steeper, and in the case of subsonic airflow, forms a front. For supersonic airflow, you'll get a shock wave.
 
Geico266 said:
What makes gravity?
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Gravity is an effect caused by the space medium and the presence of mass. Mass create a pseudo shadow effect in the space medium that creates an unbalance (vacuum) of the space medium forces acting upon an object. The out of balance object is actually pushed by the space medium toward the mass creating the shadow effect. The gravity effect appears as a pulling force to the observer just like a vacuum hose to an object. Unlike water or air mediums the space medium is of kinetic nature and probably composed of multiple different mediums orthogonal to each other.

If the presumed gravity waves were the cause of atmospheric disturbances they would be more noticeable in the form of earthquakes.

José
 
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If a plane is turbulated by a gravity wave, that wave obviously had some force. Has anyone measured the force of these waves? Can they put a detector on planes...an accelerometer of some sort?
 
scottd said:
The right temperature and wind profile in the atmosphere.




That's a good question which is still is being researched. Most gravity waves don't break. Those that do are still quite a mystery.



All.



Predicting that gravity waves exist isn't the hard part as much as predicting which ones will break and produce turbulence that we feel in the aircraft. Mountain waves are always "turbulent" using the strict definition of turbulence (atmospheric mixing). However, our aircraft are so small that we normally see this turbulence as just upward and downward movement.
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Thanks Scott! I hadn't actually expected anyone on the board to be able to answer, but this is great. The article mentioned there was a specific range of altitude that they occur, so a plane could go over or under the wave. I assumed that to mean there was a general range, but it sounds like the range may be specific to each occurrence. I picture a wave breaking to happen in a way described by MAKG1; caused by a some type of force restricting the medium, such as a mountain (or, in the case of water, the shore getting shallower.
 
Piloto said:
Gravity is an effect caused by the space medium and the presence of mass. Mass create a pseudo shadow effect in the space medium that creates an unbalance (vacuum) of the space medium forces acting upon an object. The out of balance object is actually pushed by the space medium toward the mass creating the shadow effect. The gravity effect appears as a pulling force to the observer just like a vacuum hose to an object. Unlike water or air mediums the space medium is of kinetic nature and probably composed of multiple different mediums orthogonal to each other.

If the presumed gravity waves were the cause of atmospheric disturbances they would be more noticeable in the form of earthquakes.

José
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Sorry, the out of balance theory doesn't work so well for people on the other side of the earth. ;)

He facts are we have no idea what causes gravity. We have a few guesses, but no one knows for sure. :no:
 
Geico266 said:
Sorry, the out of balance theory doesn't work so well for people on the other side of the earth. ;)

He facts are we have no idea what causes gravity. We have a few guesses, but no one knows for sure. :no:
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I guess you do not have a clear understanding of the concept. But it describes very well the gravity effect for objects on the Earth Surface as well for orbital mechanics. Unlike air in the atmosphere or water on the seas the space medium is a vector kinetic medium rather than a static pressure medium. This is why a mass can cause an action at distance in space but not submerged in water (analogy). What is more difficult to explain than Gravity is the Inertia effects on an object or the interactive forces of electromagnetic fields created by rotating electric fields. If you can figure this two apply for the Nobel Prize.

José
 
TangoWhiskey said:
http://news.discovery.com/earth/gravity-waves-may-cause-clear-sky-turbulence-121206.html
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Holy confusing terminology Batman!

At first I thought this was going to be some nonsense based on gravitational waves: http://en.wikipedia.org/wiki/Gravitational_wave

But no, it is about gravity waves: http://en.wikipedia.org/wiki/Gravity_wave

I'm familiar with both concepts, but was unaware that the term "gravity waves" had been applied or defined for the second concept. Needlessly confusing. Who is in charge of these things and how can I get their license to define terms revoked?
 
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Jim Logajan said:
Holy confusing terminology Batman!

At first I thought this was going to be some nonsense based on gravitational waves: http://en.wikipedia.org/wiki/Gravitational_wave

But no, it is about gravity waves: http://en.wikipedia.org/wiki/Gravity_wave

I'm familiar with both concepts, but was unaware that the term "gravity waves" had been applied or defined for the second concept. Needlessly confusing. Who is in charge of these things and how can I get their license to define terms revoked?
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You are very right Jim. To me the math does not add up. Since any significant gravitational changes on the atmosphere will be more noticeable on the earth surface either as an earthquake or sunami.

José
 
Piloto said:
I guess you do not have a clear understanding of the concept. But it describes very well the gravity effect for objects on the Earth Surface as well for orbital mechanics. Unlike air in the atmosphere or water on the seas the space medium is a vector kinetic medium rather than a static pressure medium. This is why a mass can cause an action at distance in space but not submerged in water (analogy). What is more difficult to explain than Gravity is the Inertia effects on an object or the interactive forces of electromagnetic fields created by rotating electric fields. If you can figure this two apply for the Nobel Prize.

José
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It's magic. :dunno: Can I collect the Nobel Prize money? :rofl:

It is fascinating conversation. :D

I'm worried about all the drag on earth's rotation caused by all of the new wind generators. Global slowing is real. :dunno:
 
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Add me to the chorus of physics students saying the label "gravity waves" for CAT is nonsensical.
I like their research but I reject their nomenclature.

Just to be clear I was a Physics student a half century ago, but not much has changed.
Schrodinger's cat is still dead, or not.
The position of the electrons in my body are still uncertain.
I do like very much the later work of Feynman. What a character.
And gravity waves still have not been detected in spite of suspending multi ton billets of aluminum in a vacuum chambers here and there.
 
Geico266 said:
It's magic. :dunno: Can I collect the Nobel Prize money? :rofl:

It is fascinating conversation. :D

I'm worried about all the drag on earth's rotation caused by all of the new wind generators. Global slowing is real. :dunno:
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Check with Obama. If he can get it anyone can.:D

José
 
Piloto said:
Check with Obama. If he can get it anyone can.:D

José
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Okay, that was very funny!

If you would please explain your theory in more detail. I truly am interested in learning what you know. I find it very interesting that man ( in general) thinks they know what will happen in the future, but has little understanding of what is happening now.

I understand the wobble theory to a lesser degree than you, but knowing action and reaction there has to be an undesirable effect some where.
 
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