The Earth's atmosphere rotates along with the Earth. At what altitude does the atmosphere cease to rotate along with the Earth? Is it the altitude at which Gravity has no effect? Forgive me if it is a dumb question. I don't know too much about science.


migrated from aviation.stackexchange.com Nov 6 '17 at 7:43

This question came from our site for aircraft pilots, mechanics, and enthusiasts.

  • 2
    $\begingroup$ Air spins with Earth until there is no air, exactly like load travels with a truck on a road. Gravity never ends but decreases with distance. Earth gravity has an effect on the Sun, for instance. $\endgroup$ – mins Nov 5 '17 at 22:21
  • 2
    $\begingroup$ Why should ist seize? There's nothing up there trying to stop the air moving with earth. $\endgroup$ – sweber Nov 5 '17 at 22:22
  • $\begingroup$ @RonBeyer, agreed. $\endgroup$ – BillDOe Nov 6 '17 at 0:09

Upper atmospheric air is coupled by friction to lower atmospheric air. So it will on the average spin near the same rotational rate as lower atmospheric air. The friction coupling to lower atmospheric air is greater than to the higher and thinner air.

Gravity always has some effect, it just gets less as one is further from the gravitational source. Think tides of the oceans getting manipulated by the sun and also the moon, both which are a good distance away, but still have some (quite measurable) effect.

Since air has mass, there is some inertia, however the air at higher altitudes is coupled via friction to lower atmospheric air, so any inertial forces are effectively coupled to the daily rotation of the earth, not to some "stopped" movement.

So bottom line, the air rotates around the earth daily, and is coupled via friction and other properties to the air below it, which is coupled more strongly to the surface of the earth. Think of a bunch of people walking around a round swimming pool, with the water spinning with them

  • $\begingroup$ But then there's the Coriolis force. $\endgroup$ – TomO Nov 8 '17 at 19:16
  • $\begingroup$ @TomO, absolutely. I tried to keep the answer simple and general. Also, I am under the general belief, although I don't recall from where, that the frictional and surface tension forces in the atmosphere are stronger than the inertial forces, as Coriolis. $\endgroup$ – mongo Nov 8 '17 at 20:35
  • $\begingroup$ But I do know that long range guns have a sight correction for Coriolis. $\endgroup$ – mongo Nov 8 '17 at 20:38
  • $\begingroup$ Point taken. Still, the observable local jet stream complicates matters. $\endgroup$ – TomO Nov 10 '17 at 18:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy