Earth atmosphere thickness and gravity of the Sun and moon.

[alpha2cen]

We have atmosphere which covers our solid Earth.

And sea water height is affected by the gravity of the Sun and moon.

But till now, I have never heard about atmosphere thickness is affected by the gravity of the Sun and moon.

Is our Earth atmosphere thickness not affected by the Sun and moon?

[swansont]

Yes, gravity has an effect, but it's not the only one.

 

http://en.wikipedia.org/wiki/Atmospheric_tide

[D H]

Yes, gravity has an effect, but it's not the only one.

Gravity has a very small, barely observable, effect, even in the upper atmosphere (which is where the atmospheric tides are most observable). The effects of solar heating (aka "thermal tides") swamps the gravitational components of the atmospheric tides. The diurnal bulge that results from this solar heating has a marked effect on vehicles in low Earth orbit. Properly modeling this bulge is important if one for precision orbit determination of such spacecraft. This is however a perturbative effect, so modeling the relatively small gravitational effects of the Moon and Sun on the atmosphere isn't all that important from an orbit prediction perspective. Moreover, the uncertainty in the predicted thermal effects is huge, much larger than the gravitational influences. Modeling the gravitational contributions to the atmospheric tides falls in the "why bother" camp -- in this particular domain, at least.

 

 

BTW, the Moon and Sun also induce tides on the Earth itself. The Earth is not a rigid body, so it too is subject to tidal influences. These are called Earth tides or solid body tides. See http://en.wikipedia.org/wiki/Earth_tide.