Does Anyone Have an Answer?

[Baddad (Marty)]

Hi All,

This observation has disturbed me for years. I have never been able to ask the right people.

The Earth rotates West to East as we 'see' it. If I'm wrong there then there is no question.

Yet the weather patterns and jet stream travel the same direction. Give or take latitude.

I would have expected the weather patterns and jet stream to travel the opposite way.????

There must be a reason that this occurs. Can anyone enlighten me on this issue? I will finally get some sleep at night.

Thanks for reading
Marty

[DavidU (Dave)]

Marty, the Jet stream is generated by the temperature difference of two air masses.
http://www.weatherquestions.com/What...jet_stream.htm

[Baddad (Marty)]

Hi Dave,

That explains part of it. There's still a lot missing. I was taught in school, shortly after the demise of the Dinasours, that the jet stream was caused by the rotation of the Earth.

That teacher's credibility just went to zero.

Thanks Dave,

Cheers Marty

[Vartigy]

Got a rough answer to why weather follows the same direction as earths rotation.

I think it's very similar to the "water in a bucket" theory.

If you fill a bucket with water tie a string to its handle and hang/suspend it in the air.
The bucket and water will be in a relative rotational equilibrium state.
Now start spinning that bucket, you'll notice at first that the water inside remains motionless, save for some vibrational ripples.
As that bucket spins faster you'll notice the water begins rotating in a similar direction with noticeable centrifical forces pushing the water outwards up the wall until they both reach a new rotational equilibrium.

I believe that this theory can be applied to (very fundamentally, bound to not have all the correct aspects) why the weather follows the earths rotation.
As "weather" is essentially a fluid being primarily comprised of water and air/gas (which is also considered a fluid).

[Baddad (Marty)]

Hi Aaron,

Thanks for that. I understand what you say. But the weather does not follow the Earth's rotation. It is ahead of it. Its travelling faster than the surface. If the bucket explanation was correct then the weather patterns would be going East to West. ie Slower than the Earth's rotation.

Cheers Marty

[Vartigy]

Speed is all relative.
After having hit the submit button, i immediately thought on that fact too.
And just put it down to pure ass. Nature showing off that she can break all the rules.

But meh, that was my guess.

But then on the other hand. Chuck Norris does run West to East, could be the negative draw of air behind him because he runs so fast.

[Robh (Rob)]

I'm no expert on the physics of weather but I think the reasoning runs something like this ...
The hotter air near the Equator tends to rise into the atmosphere. For latitudes above the Equator, the hot air moves northward as cooler air moves down from the north polar region. For latitudes below the Equator, the hot air moves southward as cooler air moves up from the south polar region. Jet streams occur where hot and cold air masses mingle. Here the Coriolis Effect comes into play. Any point on the Earth's surface has a velocity from east to west due to the Earth's rotation. However, points near the Equator are moving faster than points at higher and lower latitudes. As hot air moves towards the poles its momentum keeps it moving eastward but its speed increases eastward relative to the ground.

Regards, Rob.

[sjastro]

Yes it's the Coriolis effect.

A coriolis force is a fictitious or pseudo force much like the backward force which is experienced when we accelerate in a car.
The car is an accelerated frame of reference. Since objects prefer to be stationary or travel at constant velocities (=zero net force) a fictitious force is produced in the opposite direction of acceleration.

Similiarly the Earth's rotation is an accelerated frame of reference. The Coriolis force is perpendicular to the axis of rotation.

In the southern hemisphere weather patterns veer in an easterly direction as a result. If there was no rotation the direction of weather pattern movements would be random.

Steven

[Vartigy]

so i was partially right.

and it is all relative.

p.s. that backwards force is experienced due to inertia i think.

[Baddad (Marty)]

Hi All,

Thanks Rob, Sjastro & Aaron. Now that starts to make sense. I had an inkling that the speed of rotation at the higher latitudes being less had something to do with it.

Its like the air masses are accelerated near the Equator and as they drift towards the poles their surface speed is faster than the Earth's rotation.
Now I know the name for that effect. Thanks guys.

Cheers Marty