Carbon Dioxide Question?

[Gankfest]

How does Carbon Dioxide get trapped in the upper atmosphere if it's heavier than other particles in the atmosphere? For example if you take a canister of water and add dry ice, and bubbles start to pour out. The bubbles will sink to the ground and not float, because it's heavier than the air around it. This got me wondering how Carbon dioxide gets stuck up in the Stratosphere. Thanx!

[John Cuthber]

Wind and convection currents mix the gases (diffusion would do it too- but more slowly)

[StringJunky]

Wind and convection currents mix the gases (diffusion would do it too- but more slowly)

In the absence of wind and convection currents, they would be evenly distributed?

[John Cuthber]

In the absence of wind and convection currents, they would be evenly distributed?

Not strictly, but the change in concentration(s) with altitude would be tiny.

You are, in effect, comparing the kinetic energy of the molecule to it's potential energy.

If you "dropped" a molecule from 1 metre in a vacuum, how fast would it hit the floor?

Compare that to the speed of typical air molecules- about the speed of sound, and you see why gravity isn't going to affect them much.

[StringJunky]

Not strictly, but the change in concentration(s) with altitude would be tiny.

You are, in effect, comparing the kinetic energy of the molecule to it's potential energy.

If you "dropped" a molecule from 1 metre in a vacuum, how fast would it hit the floor?

Compare that to the speed of typical air molecules- about the speed of sound, and you see why gravity isn't going to affect them much.

I've got a set Planckian tweezers somewhere to drop one.

 

Yes, that makes sense.

[John Cuthber]

It may be more practical to drop a collection of molecules at the same time, say a million million million million of them.

[Ken Fabian]

I believe the short term behaviour - that sinking of the more dense gas as it is released into air - is called a "bulk phase effect" and happens because it is not yet well mixed and there is a significant difference in gas density between it and surrounding air.

 

What will happen is that it will mix and be dispersed, even from the bottom of a deep open topped container. Even in the absence of any mixing from large scale air movements (wind, convection), mixing will happen because of "diffusion" and diffusion happens because molecules of gases are always in motion - called Brownian motion - and for CO2 at 15 degrees C for example, the molecules are moving at about 400 metres per second; 1 gee of gravity (9.8m/sec*2) is not enough to make much difference to that motion compared to that of the other lighter and faster moving molecules like N2 and O2. Very high gravity/centrifuging or very cold temperatures would be needed to overcome that mixing effect of Brownian motion of gas molecules.

[Gankfest]

Cool, tried Googling it, but wasn't answering my question. Figured it was some mixture of particles, or wind pushing the particles upwards. Anyway thanx for the answers, answered my question.