Cloud motion relative to Earth?

[ayunet]

Would like to know if any of you have ever wondered when clouds are seen to be stationary with reference to the ground, could it be that:

 

a) the winds are moving the clouds at the same speed as the earth's rotation?

 

~OR~

 

b) is it that when the earth spins, the whole atmosphere, including the clouds, moves along with it?

And if this is the case, what causes the clouds to move along with the Earth? Is it due to gravity?

 

All help are greatly appreciated.

Thanks in advance.

[insane_alien]

b) and its because of friction and the viscosity of air.

 

if it didn't then we would have 900 mile per hour winds at the equator. not a nice situation.

[Bignose]

It is a classical assumption from fluid mechanics that the fluid immediately next to a solid object has the same velocity as that solid object. Usually, this is used to set the fluid velocity to zero at a pipe wall, but the reverse is also true. The fluid, air in this case, near the earth's surface is moving at the same velocity as the earth itself. Of course, we are moving too, so relative to our point of view there is no movement, but the air and everything, including the clouds, is moving together.

[ayunet]

Thanks to all for the reply. Would like to add an extension to the question.

 

When the Earth is newly formed, I believe that the atmosphere is in choas as in the movement of the whole atmosphere is not orderly. Winds and clouds are being blown about all over the place as it is in some of the other planets.

 

What causes the atmosphere to stablise and rotate along with the Earth? Is it once again due to fluid mechanics?

 

More elaboration of answers will be greatly appreciated.

Thanks in advance.

[insane_alien]

what do you mean? the atmosphere is chaotic on earth as it is on other planets. on other planets the atmosphere travels with the surface as well.

 

overall if you took the average velocity of all the gas molecules then you would see them rotating with the planet(be it jupiter, earth, venus, even stars). if you look at certain bits of the atmosphere then you will see anomalies. on earth we call this weather. we also call it weather anywhere else its observed.

 

weather is caused by the uneven heating of the earths surface and the coriolis force. this produces everything from hurricanes to a light drizzle.

[Klaynos]

IIRC the atmosphere and planet have always been spinning together because they where both in the spinning cloud that formed the planet....

[insane_alien]

even if by some random chance they weren't the viscosity of air would eventually spin the atmosphere up to speed in a few thousand rotations.

[Klaynos]

even if by some random chance they weren't the viscosity of air would eventually spin the atmosphere up to speed in a few thousand rotations.

 

yes indeed

 

And that would be far more fun to watch...