[neilep (OP)]

Dearest Atmospheric Academics,

How much (if any) atmosphere is lost per day/week/year (whatever) to space ?

Is there any leakage or does gravity have a pretty good hold on it ?....there must be a fine line yes ?

If we do lose an amount...does earth make up for it ?

[another_someone]

I do remember this being raised as a side issue on another question, and the comment being made that what we lose through leakage is more than made up for by material brought in by meteor showers, and other extra terrestrial sources.  Don't recollect the numbers though.

[another_someone]

http://en.wikipedia.org/wiki/Solar_System#Interplanetary_medium

Earth's magnetic field protects its atmosphere from interacting with the solar wind. Venus and Mars do not have magnetic fields, and the solar wind causes their atmospheres to gradually bleed away into space. The interaction of the solar wind with Earth's magnetic field creates the aurorae seen near the magnetic poles.

[DoctorBeaver]

Strangely enough I was reading about this today. The answer is yes, the atmosphere does leak away.

Water molecules in the upper atmosphere get broken down into the constituent hydrogen & oxygen molecules and the hydrogen goes walkabout into space. However, don't panic. It's estimated that in the entire history of the earth only 0.2% of the atmosphere has been lost in this way.

[einfopedia]

Oxygen is constantly leaking out of Earth’s atmosphere and into space. Measurements taken by satellites during the 1980s and 1990s showed the escaping ions were traveling faster the higher they were observed. This implied that some sort of acceleration mechanism was involved.

[imatfaal]

Oxygen is constantly leaking out of Earth’s atmosphere and into space. Measurements taken by satellites during the 1980s and 1990s showed the escaping ions were traveling faster the higher they were observed. This implied that some sort of acceleration mechanism was involved.

  Do you have a link on that please - the observation I can believe, the causation I am not so sure about