Hello I actually had posted this question, but onto a wrong thread, so here's the question (gottabe in the right thread now) Can earth somehow maintain the volume of its atmosphere? Personally, my answer is no. Multiple gravity forces from all over universe pull the air away, while meteorites and other 'space invaders' splash into the atmosphere and throw away some portion of it (just like when the water drops thrown from a pool when a massive thing falls into it). After a period of time, the earth will be fluidless. What say you?
locked oxygens.... did you try to imply that we could decompose oxide stones into oxygen and other mineral? As for how long..... okay, I think I may contradict myself again, or add more theory: The closer the air to earth, the thicker it becomes because of a combination of gravity and pressure. The more air particles leave the earth, the thinner the air becomes, but thanks for gravity, the closer the air to earth, the harder it is to pull it away from earth, but given that atmosphere height may not reach a magnitude similar to that of earth's radius, the difference of the forces may not be that significant, so the loss is still possible.
"did you try to imply that we could decompose oxide stones into oxygen and other mineral?" Sounds fine to me. "The closer the air to earth, the thicker it becomes because of a combination of gravity and pressure. " Sounds fair enough to me "more air particles leave the earth, the thinner the air becomes," You mean further out, right? "but given that atmosphere height may not reach a magnitude similar to that of earth's radius, the difference of the forces may not be that significant," Whats atmospheric depth got to do with it? It comes down more to the escape velocity of the atoms and molecules involved, ratehr than pressure, surely? I seem to recall reading that helium on its own has enough motion, whatever, in it that it just jumps straight up and out the atmosphere. Heavier atoms cannot, because they lack the energy, hence loss of more thana little bit of atmoshpere is impossible.
An encyclopedia article I read adressed this issue. Atmosphere is constantly being lost, due to the reasons listed above, and some is being gained, due to things like comets vaporizing on reentry, and by the time our atmosphere starts getting thin enough to worry about(in a few billion years), we'll either have evolved and adapted to it, Biblical Armegeddon will have happened, or we'll be more worried about the sun going supernova.
atmosphere gain? How nice...... So we needn't worry about that for now, right? But wait.... will the aging sun effect this atmosphere loss? You know, when the sun gets old enough, it will grow...
According to: The Cambridge Encyclopaedia of Earth Sciences: "The Earth's atmosphere is now relatively stable, with minor losses induced by specialized processes. Only hydrogen and to a lesser extent helium can escape from the upper atmosphere into space, a process known as thermal evaporation. Hydrodynamical loss involves the escape of gases when local supersonic velocities are attained. Photodissociation, the break-up of gas molecules by incident solar radiation, may enhance the loss of hydrogen by converting ammonia (NH3) into its constituent nitrogen and hydrogen molecules. Combined losses are not at present appreciable." With regard to combined oxygen in the crust, oxygen is present in about 456000 parts per million. The percentage of oxygen in the upper mantle is: SiO2 45.16% MgO 37.49% FeO 8.04% All other oxygen compounds below 5%. Mass of crust: Continental crust 1.6 x 10^22 kg Ocean floor crust 7.0 x 10^21 kg For comparison, the approx. mass of the atmosphere is about 5.3 x 10^18 kg. Hope this helps.
Thanks and welcome By the way, since hydrogen and helium are the ones which escape the most, what are the things that (can) keep the amount of the two gases in atmosphere? Oh, and if the amount of hydrogen were to drop constantly, would it affect worldwide hydrology?
~Thanks and welcome~ Thank you for the welcome. ~By the way, since hydrogen and helium are the ones which escape the most, what are the things that (can) keep the amount of the two gases in atmosphere?~ First, amounts quoted as follows: He 0.00052% H20.00005% Loss of He is very low. "It is estimated that about two thirds of all hydrogen atoms present will escape in about a thousand years." and "As all hydrogen compounds are subject to photochemical dissociation, their lifetime in the upper atmosphere is short." So hydrogen compounds are split into hydrogen (and whatever) and this hydrogen is 'rapidly' lost. If hydrogen compounds include water Please Register or Log in to view the hidden image! then there is no shortage of replenished hydrogen. ~Oh, and if the amount of hydrogen were to drop constantly, would it affect worldwide hydrology?~ Not my subject but from the above it looks like continual loss of water. However, it has been going on for a long time and there is still plenty left. Please Register or Log in to view the hidden image!
Next question: With Hydrogen getting less and less available and affecting the amount of water (though not drastically), Does it mean that the oxygen concentration in air increases too?
curioucity "With Hydrogen getting less and less available and affecting the amount of water (though not drastically), Does it mean that the oxygen concentration in air increases too?" Well, yes, there will be a net loss of hydrogen but the oxygen does not have to stay in the atmosphere. Some can be breathed into carbon dioxide (some of which react with calcium etc. to form solids) , some can oxidise other substances e.g., any combustion, volcanic emissions; some can dissolve in the oceans. Also meteors burn up in the atmosphere using oxygen. There may be mechanisms for water arriving on Earth e.g., from comets.
I wonder about something... Did this atmosphere loss contribute to the changes of Ice Age? Also, would it be possible that the H2 loss supports the theory that former earth life was aquatic because of too much water on earth?
~Did this atmosphere loss contribute to the changes of Ice Age?~ How do you mean? ~ Also, would it be possible that the H2 loss supports the theory that former earth life was aquatic because of too much water on earth?~ Don't think so. Life probably easier to develop "in solution".
Thanks for the reply. About the Ice Age thing, possibly it wasn't affected by atmosphere loss which slowly reduce the amount of H2O available on earth. So actually I asked if the decrease of H2O contribute to Ice Age...
curiocity ~So actually I asked if the decrease of H2O contribute to Ice Age...~ I don't believe so. Check this: http://deschutes.gso.uri.edu/~rutherfo/milankovitch.html
