Talk:Atmosphere of Earth/Archive 1

Atmosphere composition

I just reworked a few sections. For some reason I was not logged in anymore when I submitted the changes; they were the two changes after the july 18 edit by cos111 (me).

I am not exactly an expert on global warming and climate change, but I think what I did with that is a lot better--better introduction and explanation, and a little more NPOV. user:cos111 2003-07-19

What on earth happened to this article?! Shatha 22:34, 10 March 2006 (UTC)

"Evolution of Earth's Atmosphere" asserts that a molten earth causes an unstable atmosphere. Why? Gas giants have non-solid surfaces and they have stable atmospheres.

There are still some problems here - some minor changes need to be made for clarity's sake, but some genuine factual errors need to be fixed. It was not heat that drove away hydrogen and helium, it was lack of gravity combined with solar wind. If those changes haven't been made when I check back, I'll make them. Otherwise, have at it. Denni 18:20, 2004 Jan 18 (UTC)

...well actually, in order for Helium and Hydrogen(molecules) to become bouyant in an atmosphere they require heat. But in combination with atmospheric conditions which would include things like gravity and external forces... --Hard Raspy Sci 18:36, 11 Feb 2005 (UTC)

Note that even within this region [Ozone layer], ozone is a minor constituent by volume.

Just as well, because otherwise you might die of ozone poisoning if you fell out of a supersonic airplane.

Units

This article has a mixture of British and US spellings. Not sure which way the article started, but spelling should be changed to one way or the other.

(It's amazing how bad an article looks with a mixture of the two, IMHO)

Duk 23:23, 11 Sep 2004 (UTC)

Looks like someone onece chnged all units from kilometers to miles. Another one reverted changes of the page, but not of the picture. Anyone knows, how to get an old picture back? Or may be it's better to create an image with all units on it? (and also note all the values inside an article with an appropriate notice? - like 10km (16mi)Mihail Vasiliev 18:50, 28 October 2005 (UTC)

Incorporate from Air

Air was turning into a weak mirror of this article, so I cut its head off and made it a disambig. This is the information that was removed, feel free to incorporate it as is seen fit.

Dry air is roughly 79% nitrogen, 20% oxygen, and 1% argon. Air may contain 0-7 % water vapor (the 79%, 20% and 1% become accordingly a little less), and less than 1% carbon dioxide. The composition of air changes with altitude; also exhaled air contains a greater percentage of carbon dioxide than what is inhaled, ca. 4.5%. There is a more accurate chart athttp://education.jlab.org/glossary/abund_atmos.html. Pressure decreases with altitude; this is why aircraft have pressurised cabins. The air pressure inside aircraft cabins is maintained at a pressure higher than that outside, for the comfort of the passengers and crew, although for fuel efficiency reasons the pressure is still slightly lower than at ground level. With a decrease in total air pressure, the partial pressure of all the component gases (including oxygen) decreases. Mountain climbers must carry a supply of oxygen on their way up to the summit of high mountains to ensure the partial pressure of oxygen in their blood is maintained.

--Ben Brockert 01:21, Oct 21, 2004 (UTC)

Composition table

The composition table is misleading and a bit redundant. The totals given indicate 9 significant figures - far more precision than is possible. The totals thus are misleading and should be eliminated. If we don't worry about the fictitious total then we don't need the Normalized to 100% column at all (doesn't total to 100% anyway) it is meaningless. I would recommend following the NASA site used as a source and give the minor compnents in ppm thereby eliminating all those meaningless zeros and any need for totalling. CO₂ and methane are indeed quite variable both spatially and temporally and the values given are only an average. I plan to modify the table drastically unless someone can present good reasons to keep it as it is. Vsmith 04:51, 1 Jan 2005 (UTC)

The "per NASA" part of the table has the same number of signifcant figures as the NASA page; the other column has two more sig figs for each number, otherwise the adjustment doesn't get it much closer to 100%. The adjusted figures were used to create the pie chart. Reporting the numbers in percent and PPM is inelegant. --—Ben Brockert (42) UE News 06:35, Jan 1, 2005 (UTC)

Removed un-needed normalized column (noted the normalization in the figure caption). The values in the figure are misleading in that they imply a Andrew K Robinson 01:59, 14 August 2007 (UTC)greater precision than is justified by the data. Please review the meaning and rules for significant figures. The total is now to correct # of sig. figures, but as noted above is rather misleading due to variability noted and should probably be cut. As for ppm and elegancy - nonsense. Should be as ppmv. Perhaps the inelegancy of ppmv would negate the perceived need for a 100% total. I may return to rid this mis-leading elegance :-) -Vsmith 03:38, 6 Feb 2005 (UTC)

If you change some of the values from the reference, you need to adjust the others. As CO₂ increases the fraction of O₂ and N₂ decrease in the last digit. This should at least be noted. Archimerged 14:42, 15 January 2006 (UTC)

COMMENTS: BIOL 1409.2426 (Student Joseph Cahill): (State your opinion of the need or lack of need to be more environmentally friendly).

It is my opinion that we MUST become more environmentally friendly immediately! Simple steps can be taken everyday by anyone who make this a priority. Recycling is the easiest way to begin to help out. I personally make a point of recycling all plastic, cans and other materials like paper that I can everyday. I have three bins set-up in my house to store and collect the items. I use cloth bags when I shop and ensure every container I use can be recycled.

On the topic of the Global Warning, it is my opinion that society is slowly becoming aware of the need to reduce ozone gases. Baby-steps are being taken by the auto industry to create hybrid and fuel cell cars. The demand for the hybrid cars is mainly based on the increase cost of petroleum gas NOT because suddenly all drivers realize the impact of combustion engines. I wish that the huge sales of the successful Toyota Prius Hybrid were ALL because of environmental concerns, however it is more about the cost of operation. Damage to the Earth's atmosphere has an impact on ALL living things. This is scary because if one link in a food chain is disturbed it affects the entire chain.

• I agree with you. And I have updated the concentration of CO2 to 380 from 350 as it has changed - The reference may no longer be valid.--Max Randor 12:46, 5 June 2006 (UTC)

Why not simplify the percentages more? Two decimal places would surely be accurate enough for elements that account for more than 0.01%, one decimal place for those over 1%, and integers for those over 10%. And why does the total significantly exceed 100%? --Andrew K Robinson 01:59, 14 August 2007 (UTC)

Did you read reference 2 at the top of the table? It explains (to some extent) an excess of 32 ppmv, although my total exceeds 100% by about 50 ppmv. Art LaPella 04:37, 14 August 2007 (UTC)

Page name

Shouldn't this be at Atmosphere of Earth? - Fredrik | talk 16:42, 11 Mar 2005 (UTC)

That now re-directs here. Vsmith 16:51, 11 Mar 2005 (UTC)

Heterosphere

There's a layer in the atmosphere where the composition varies with altitude, called the heterosphere. This article divides them by temperature, so I don't know where it fits. But for example, there's an altitude (depending on solar activity) at which helium is the dominant gas. See [1]. --Andrew 06:42, Apr 2, 2005 (UTC)

I stuck it in composition. --Andrew 03:25, Apr 10, 2005 (UTC)

The strucutre of the atmosphere is generally defined in three different ways. The most common is by temperature strucutre. The other two ways is by composition (i.e. the heterosphere and homosphere) and by "function" e.g. "ozonosphere". I'll work to make this clearer in the page. --kmcolo

Early atmosphere - a merge might be in order

In case people watching this article weren't aware of it, Miller-Urey_experiment#Earth's_early_atmosphere actually has more material on Earth's early atmosphere than is present here. It might be appropriate to move some of it here and include a link over there pointing to it. Bryan 23:21, 9 Apr 2005 (UTC)

Whatever it is decided to do with these two articles, they need updating to reflect the (wonderful/beautiful imho) recent result of Tian et. al. [2] [3]. This paper was even reported on in Slashdot, it really looks like it may become a landmark in the history of ancient atmospheric science research. Urey-Miller is now fully back "in the game"! (yay! :o)--Deglr6328 02:36, 10 Apr 2005 (UTC)

Heh. I noticed this duplication between articles when I went to add information about those very results. :) I'm not an expert in the field, though, so by all means expand and improve on the material I added. Bryan 05:55, 10 Apr 2005 (UTC)

Nice research, that. I wonder how often experts considered or overlooked supersonic gas movement. One sometimes forgets the behavior of planetary-scale quantities of material. (SEWilco 18:46, 10 Apr 2005 (UTC))

• Any links to the concepts underlying the planetary formation process which they are using? (SEWilco 18:46, 10 Apr 2005 (UTC))

The new study indicates that up to 35 percent of the early atmosphere was oxygen (200 - 250 million years ago, bubbles of early atmosphere were found in an amber).

Refractive index etc.

If this is going to be the page on the air we breathe, it should have a section on the physical properties of ground-level air: refractive index, conductivity, electrical breakdown voltage, dielectric constant, and so on.

If not, there should be a page, maybe physical properties of air with just that sort of information (as well as ground-level composition and so forth). --Andrew 03:52, Apr 29, 2005 (UTC)

Atmospheric focus

It seems that this page has what I would call an editorial slant towards those interested in the atmosphere as it pertains to space and space travel. Though indeed this is interesting it would seem to me that the page should focus on the atmosphere with a slant towards those interested in the atmosphere. This is my observation and I will be working toward that goal. Let's discuss this here so as not to step on toes that should not be stepped on. kmcolo 17:00, 31 July 2005 (UTC)

• I think the orientation is toward the vertical levels of the atmosphere. There are separate articles for a number of processes within various layers, and you'll probably be adding a number of links to those which hadn't been connected. (SEWilco 02:15, 1 August 2005 (UTC))

Atmosphere and Gravity

I know this probably sound stupid but why dont the gas molecules in the atmosphere come fall on to the earths surface just like everyhting else. I mean they should, since they are not in orbit. Pranay ( pranay89@gmail.com )

The gas molecules do respond to the effect of gravity. Atmospheric pressure drops with increasing altitude. But gravity is a weak force, and it can only compress the atmosphere to the point where the pressure pushing molecules up (due to collisions) equals the force down. See kinetic theory of gasses. Archimerged 14:42, 15 January 2006 (UTC)

You can explain buoyancy by noting that the gasses of the atmosphere are moving in accordance with the physical principles created by the earth's gravitational field.WFPM (talk) 16:27, 3 September 2009 (UTC)

Clouds

The whole article do not mention them. TestPilot 23:16, 22 January 2006 (UTC)

Image needs to go

In his recent edit summary, William M. Connolley said: "Density and mass - Rm the quibbles from the graph: K, not deg K, is correct, but really doesn't need mentioning. Ditto the scale: it is clear enough. Put remaining text into caption, and smallify"

However, this whole graph (Image:Atmosphere model.png) is a misleading mess:

1. There is, of course, the "Degrees Kelvin" problem.
2. In addition, there is an improper symbol for kilometers (Km rather than km)
3. The use of a carat to indicate superscript in "g/cm^3" isn't pretty, but is marginally acceptable, it is understandable that software might not be able to make superscripts, but it can probably use the ³ character.
4. But the biggest problem is that there are two independent and unrelated graphs slammed together, with the crossover point of no significance whatsowever.

• Furthermore, the background grid is strongly and clearly logarithmic, but the scale for the temperature graph is not logarithmic. Only the graph for density is logarithmic, which in itself might warrant a clear explanation of that fact in the caption. It is just to damn confusing to justify this abomination. Gene Nygaard 01:28, 8 February 2006 (UTC) Gene Nygaard 03:12, 8 February 2006 (UTC)

I couldn't find a better one with a quick trawl, so I propose we leave it until someone finds a better one. If someone want to generate a better one they could try using the US Standard Atmosphere from here: http://www.pdas.com/m1.htm

If I get time I'll try and do it. Its probably also worth including a whole section (or subsection) on the US Standard atmosphere as it is widely used. At the moment standard atmosphere redirects to Atmospheric pressure which is misleading as that article seems to be exclusively about Earth's MSLP.--NHSavage 08:58, 8 February 2006 (UTC)

Um. I shall defned this graph (its not mine, I didn't put it there, but...). "Km" and "Degrees Kelvin" are mere typographical problems, and minor ones at that. Ditto ^. Now, as to the "unrelated" variables: well, T and P are both atmos variables. Putting them on the same graph is reasonable. Then there is a crossover, which doesn't mean anything - but so what? On this height scale, its natural to plot log P, and natural to plot plain T. Its not a great graph or anything, but it does usefully illustrate the article, and I don't understand the degree of dislike GN has for it! William M. Connolley 09:09, 8 February 2006 (UTC).

Photosynthesis

Certainly, these two sentences are not accurate: 1. "Being the first to carry out oxygenic photosynthesis, they were able to convert carbon dioxide into oxygen, playing a major role in oxygenating the atmosphere." 2. "Photosynthesizing plants would later evolve and convert more carbon dioxide into oxygen."

During oxygenic photosynthesis, i <3 geosystems, the water molucule is split and the oxygen from H2O is converted into the dioxygen (O2) molecule. The carbon in carbon dioxide is converted into organic matter (call it biomass or algal/bacterial matter). Although, some carbon dioxide is respired back out of the cell as carbon dioxide, there is generally a net fixation of carbon (or net conversion of carbon dioxide to organic matter).

--216.59.253.118 20:19, 15 February 2006 (UTC)

Not GA yet

This article was nominated on Wikipedia:Good articles/Nominations, but I feel it's not yet up to the required standards as the only reference cited does not appear to be adequate for verifying all the facts in the article. Worldtraveller 00:09, 12 March 2006 (UTC)

Question

I moved the following from the article to here:

what about the exosphere?????????? that is very important. you do not state the temperature in the exosphere

It was in the subsection "Various atmospheric regions". I do not know the answer. - Liberatore(T) 12:46, 6 April 2006 (UTC)

A possible error!

I am in no position to write anything about the earth as I know very little about it's scientific properties but I think I found an error. "thermosphere: from 80–85 km to 640+ km, temperature increasing with height."

It would see to me that the thermosphere's tempature would decrease with height as it is the last layer and so close to space. Am I mistaken?

Brett

It increases with height, according to every other website I looked at including [4], [5], [6], [7] and [8]. Art LaPella 03:21, 10 July 2006 (UTC)

It increases with height because the density becomes so low that the mean free path of the gas particles increases disproportionately; due to the molar gas law, the same amount of thermal energy leads to a much higher temperature (particle velocity). 65.57.245.11 (talk) 19:46, 22 October 2008 (UTC)

Reversion explanation

First, I reverted the unexplained change from 78% N2 and 21% O2 to 80% N2 and 19% O2, back to 78 and 21. These well-known figures can also be found in the body of the article and http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html

I also changed the percentage of CO2 by mass from .035% back to .053%. The .035% figure probably came from the NASA reference http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html , but that figure is "by volume, dry air", not by mass. I found the .053% figure at http://www.reference.com/browse/wiki/Earth's_atmosphere . Art LaPella 02:38, 1 July 2006 (UTC)

Splitting off air

I am considering splitting off the section on composition into a separate article at Air, along the lines of many (19, I believe) other wikipedias, such as de:Luft (separate from de: Erdatmosphäre. There seems to be plenty of information to make both articles substantial, and the air article could go into somewhat more detail (as the German article does). Rigadoun (talk) 17:25, 4 August 2006 (UTC)

hmmm not sure. I can see why this might be a good idea in the future but I think for the moment it would be better to just expand this section until the content is large enough to warrant a seperate page. There is also a possible overlap with Atmospheric chemistry and the links to this article would have to be carefully thought through.--NHSavage

exists"

Here's some brilliant prose from the article:

Although the atmosphere exists at heights of 1000 km and more, it is so thin as to be considered nonexistent.

—Pengo ^{talk · contribs} 14:40, 11 August 2006 (UTC)

This has to be sarcasm, but I don't understand the objection. Air molecules don't lay on the ground like water because they bounce off each other at widely varying speeds averaging about 1000 miles per hour. Most molecules bounce and fly miles above the earth, but they fall down eventually (a very few escape into space). The higher you look, the fewer molecules you find, and there is no clearcut limit. "How high is the atmosphere" is a semantic question - that is, it's about words, not about nature. The sentence looks good enough to me. How would you say it? Art LaPella 18:55, 11 August 2006 (UTC)

It was a bit inelegant. I've tried to improve.--NHSavage 20:11, 11 August 2006 (UTC)

Neutrality of this section

The sub section "The evolution of the Earth's atmosphere" needs to be marked as a theory. We all know that carbon dating is inaccurate after a few 10s of thousand years (cannot think of the exact amount right this moment...) and that anything beyond that is based on unproven theories and speculation. Therefore this must be marked as a theory to keep neutrality.

I am going to put the word theory at the top of it linked with the page on theories, if this is removed without explanation it will be because someone wishes to put this foward as fact when it is not proven and that is not neutral. If you have a valid reason as to why this should not be there please post it here before removing this edit and if it is a good reason then fine but saying "this is what happened" is not a good reason when it is unproven —Preceding unsigned comment added by Zealotii (talk • contribs) 06:20, 24 September 2006

Removed the theory link. The first paragraph of the section states:

The history of the Earth's atmosphere prior to one billion years ago is poorly understood, but the following presents a plausible sequence of events. This remains an active area of research.

Seems that is qualification enough. You seem to use the word proven in a manner that indicates a lack of understanding of how science works. Vsmith 16:46, 24 September 2006 (UTC)

"The history of the Earth's atmosphere prior to one billion years ago" is insinuating that the world has in fact existed for one billion years. Which is currently unprovable. Therefore it is stating as a fact that the world existed one billion years ago. Which is not a fact.

I suggest the opening of this sub-section be revised and changed to state at least a little more clearly that this is not a fact. —Preceding unsigned comment added by Zealotii (talk • contribs) 10:40, 24 September 2006

It's about as close to a fact as you're going to get in science, though. The scientific community's consensus is that there's overwhelming evidence for Earth being over a billion years old, the proposition that it's younger than that is an extreme minority notion that IMO doesn't warrant inclusion in every article that happens to mention Earth's age. Wikipedia:Neutral point of view#Undue weight covers this sort of thing. Bryan 23:36, 24 September 2006 (UTC)

Overwhelming evidence? Could you please at least give me links to this information as I would like to see this amazing evidence. —Preceding unsigned comment added by Zealotii (talk • contribs)

Age of the Earth and History of Earth both contain an abundance of references, for a start. Also, please sign your posts using four tildes, like this: "~~~~" — Knowledge Seeker দ 05:32, 25 September 2006 (UTC)

Dating methods used in those examples are not proof the world is that old at all. For instance, radiocarbon in carbon dating (most common dating method) decays far to fast to ever work for anything past a few thousand years and any knowlagable Evolutionist knows this. It's half-life is only 5,730 years, in other words half of it decays away every 5,730 years. After 10 half lives there is but a thousandth of it remaining, on since, things like diamonds (apparently dated to 3 billion years in some cases) still have radiocarbon on them, they are far, far younger then what is said. The problem here is far to much on wikipedia and in evolution in general is accepted as fact, when it is NOT fact and is FAR from it. The neutrality of Wikipedia is general is non existent and a lie. This site has so many unproven methods and theories and calls them fact, or just accepts them as true. I request that entire section be either tagged obviously as theory or removed entirely.

Sorry I took so long to reply, I had things that needed doing. "Zealotii 09:34, 15 October 2006 (UTC)"

My theory tag removed again? Why are people having such a hard time with something so simple? The only reason there are so many people that accept this kind of thing is because they assume it be to true as evolutionists seem to take great delight in tagging their documents as fact. "Zealotii 09:51, 15 October 2006 (UTC)"

Please stop wasting everyones time, including your own. If you want to debate evolution, go to an internet newsgroup. Quite why you think this stuff depends on radiocarbon dating I don't know... William M. Connolley 10:53, 15 October 2006 (UTC)

That was an example of many, my point was if it depends on ANY dating method "theory" we have now it is incorrect. I am not here to debate anything, you are preventing neutrality by not allowing a theory tag ON WHAT IS DAMNED WELL THEORY. If you were NEUTRAL you would not be here debating this with me. The truth is the truth. I am not here to debate anything. Only to correct what is being displayed as fact to theory, to prevent more wide spread and outrageous ignorance on the subject. "Zealotii 11:14, 15 October 2006 (UTC)"

Look, I will simply say this.

It IS a theory. You know this as well as I. Therefore I am CONTRIBUTING by FIXING an error which states it as fact which is INCORRECT.

There is no way to argue this save you want it removed because you want your views on this section and not the neutral truth, you want it to lean towards evolution. "Zealotii 11:18, 15 October 2006 (UTC)"

If you want to discuss evolution, do it over there or better still at the appropriate newsgroup. Everything we "know" about the world is either superstition or theory. Much of it is accepted as "fact" and under any legal system I'm aware of - as the "theory" of gravity, which you ignore at your peril, or the "theory" of optics that you implicitely use whenever you think you see something first hand. The approximate age of the Earth (give or take a few million years) is not under any serious debate. --Stephan Schulz 11:30, 15 October 2006 (UTC)

...

Those examples are irrelevant. We can see them working everyday all day and it would only be named a theory because we may not fully understand it yet. But it is still there. This, on the other hand, has nothing to go by at all save disproven dating methods. The age of the earth is always under serious debate if you had not noticed since it is a key factor in evolution, which itself is always under serious debate. "Zealotii 11:47, 15 October 2006 (UTC)"

Sorry to break it to you, but evolution is also not under serious debate among educated people. And even if it where, the age of the Earth is independent of evolution. Earth is known to be ancient (as in "billions of years old") by a number of independent and reinforcing dating processes, none of which is radiocarbon dating (which, btw. is not "disproved" either). But this discussion is off-topic here. Go to Age of the Earth if you must, but be prepared to back anything you claim up with reliable sources.--Stephan Schulz 15:03, 15 October 2006 (UTC)

No, there is no evidence or actual proven working methods. The problem with science these days is it is not science. It is people trying to prove one certain thing. Please show me reliable sources for your arguement with proof. Also, no, radiocarbon dating is flawed and any respected evolutionist scientist will tell you this. There is however, "evidence" that goes along like this: (direct quote from [9] READ THE SOURCES THIS INFORMATION IS FROM)"While it is common to cite verified predictions as ‘proof’ of a scientific law, this commits a basic logical fallacy called affirming the consequent.

1) Theory T predicts observation O; 2) O is observed; T is true.

 To see why this does not follow, consider:

1) If I had just eaten a whole pizza, I would feel very full; 2) I feel very full; I have just eaten a whole pizza.

Finding certain things in substances does not mean the actual theories are correct. All evolutionist evidence thus far is inconclusive, based on this or assumptions/unproven hypothesis. Again, if you have this evidence please show it as I would love to see it. But if you are just one of those people that assume things to be true because they release millions of new theorys about the same thing so often, that it somehow becomes truth as they never decide to show it otherwise, please rethink your comment. "Zealotii 04:50, 18 October 2006 (UTC)"

Once again, if you would teach us benighted ones the world isn't a billion years old, the place to start is at Talk:Age of the Earth - it's off-topic here until you can show us the light there. If you aren't impressed by Wikipedian policy and habits, then call it Christian deference to those placed in authority over you, or something. Art LaPella 06:41, 18 October 2006 (UTC)

Agreed with Art. I'll put Talk:Age of the Earth on my watchlist. If you want to discuss these issues, go there (although it likely is still off-topic to a certain degree). Please first read something like the talkorigins age of the earth FAQ to understand the currently used dating methods and arguments for an old earth.--Stephan Schulz 13:35, 18 October 2006 (UTC)

Again I am sorry for taking so long to reply, there were things that required my attention... I think I will go there and discuss these things further. I am well aware of the dating methods used and the current most popular, given its amazing half-life, radiometric dating (decay rate of isotopes). I also have many reasons why it is unrealiable and in some cases can help to show the oposite... But as you requested I shall not post such things here anymore. "Zealotii 10:06, 19 October 2006 (UTC)"

You are talking past each other because of a basic misunderstanding and imprecision in the use of words such as theory, fact, and truth. The very best that science can do is to establish a well-substantiated theory. Theories may always be improved, but never proven. Science pursues truth, but we can never know whether it has been reached. A fact is not the opposite of a theory, and truth and fact are not synonymous. Proofs belong in the disciplines of mathematics and logic which of course are helpful to scientists as they make observations (gather facts), formulate hypotheses, test those ideas, and develop theories to explain what they observe--and the process continues. The moment someone tells you that a scientific theory has been proven, you should be extremely skeptical. History is replete with theories "proven" and then later found to be incomplete, or flat wrong! There are various theories about the evolution of the Earth's atmosphere. Some of them are pretty well substantiated by scientific evidence. Science is a human enterprise. I leave truth to the realm of God. Norm 21:29, 15 April 2007 (UTC)

A better argument would be to mention that for rocks more than several thousand years old, Potassium-Argon dating is used. Check out this link. Zealotii is correct, carbon dating is not useful in this time range. Good thing is, we have other ways to date old material. One must remember that as precise as science seems at any given moment, few things are completely proven...hence the idea of theorems. Wikipedia also is against the idea of "weasel wording", so items sometimes have to be stated as complete fact, even if they aren't. All they need to fit is the current consensus argument, regardless of apparent truth. Thegreatdr (talk) 17:32, 8 January 2008 (UTC)

Thickness of atmosphere. Could this actualized set of data be changed in the page?

Where it says:

However:

• 57.8% of the atmosphere by mass is below the summit of Mount Everest.
• 72% of the atmosphere by mass is below the common cruising altitude of commercial airliners (about 10000 m or 33000 ft).
• 99.99999% of the atmosphere by mass is below the highest X-15 plane flight on August 22, 1963, which reached an altitude of 354,300 ft or 108 km.

Therefore, most of the atmosphere (99.9999%) by mass is below 100 km, although in the rarefied region above this there are auroras and other atmospheric effects.

Should say:

However:

• 68.054% of the atmosphere by mass is below the summit of Mount Everest.
• 73.004% of the atmosphere by mass is below the common cruising altitude of commercial airliners (about 10000 m or 33000 ft).
• 99,000 072% is below 31200 m.
• 99,901 189% is below 48200 m.
• 99,990 117% is below 65100 m.
• 99,999 006% is below 79800 m.
• 99,999 901% is below 92900 m.
• 99,999 991% of the atmosphere by mass is below the highest X-15 plane flight on August 22, 1963, which reached an altitude of 354,300 ft or 108 km.

Therefore, most of the atmosphere (99,999 970%) by mass is below 100 km, although in the rarefied region above this there are auroras and other atmospheric effects. —The preceding unsigned comment was added by JustToHelp (talk • contribs) 19:50, 13 January 2007 (UTC).

Just changed the unsourced numbers to published figures from a standard text. The above calculations by User:JustToHelp would appear to have WP:OR problems as he states the numbers were derived by spreadsheet calculations. Sourced published figures are preferred. Vsmith 20:14, 13 January 2007 (UTC)

Reverted JustToHelp's OR calculations again. This time he inserted them following the citation I had given for the tabulated data, thereby making it seem as though his numbers were cited. His values - calculated to six decimal places are quite absurd as the uncertainties of the data would make such precision meaningless. Let's stick with published values and forego the OR calculations. Vsmith 23:34, 15 January 2007 (UTC)

Would you please take a look to NRLMSISE-00 and/or so we can start talking about facts.

You say that 6 decimal numbers are absurd, then: why is there a 99.99997% number accepted?.
Look, I have had in the past a difficult time triyng to understand how thick the atmosphere was. There should be a limit we can accept as "enough". I looked to a lot of pages on internet and always there was no clear answer to this "perceived" limit. Then I discovered that I could help other to find a fast awnswer by posting at wikipedia. So, i downloaded all the nedded data from NRLMSISE-00 and built an "acceptable" answer to all. Then to help others I posted my findings on this page, more than a year ago. Do you think that it is needed to force others to calculate an awnswer because you dislike what I have posted?
Now that section just got changed and the verion you want to IMPOSE is not the best it could be IMHO. So i tried several times to improve, and the only awnswer you see fit is: ERASE ALL, IT'S NOSENSE. Do you think that it is needed to force others to calculate an awnswer because you dislike what I have posted?
Why dont look at the data and not your opinion that this is OR and MUST be erased. Do the data presented contradict the information you wnat to belive? Is wrong to try to improve on what is presented? Pleased DO READ the facts not opinions. If you dislike the form, not the facts, please help to correct. The facts, either you like them or not would persist and be there. Your opinions will change with time. JustToHelp 05:03, 16 January 2007 (UTC)

OK, I looked at NRLMSISE-00. There should not be a limit on how high is enough - JustToHelp's own graph shows the air fades away gradually with no sharp limit. 99.99997% isn't a 6 decimal estimate if you think of it as the complement of 0.00003%, with 1 significant figure. JustToHelp's 73.004%, for instance, has 5 significant figures and a fraction of a degree temperature difference would be enough to make it wrong. The issue isn't whether to force others to calculate the figures - the issue is two competing sets of figures. Vsmith has provided documented figures, not his own calculations. JustToHelp's figures apparently come from [10], a website that provides calculations, but the underlying formulas aren't reviewed the same way as a scientific paper is. If JustToHelp addresses the problems above, the real scientists (that is, not me) will, um, have more time for him. Art LaPella 06:07, 16 January 2007 (UTC)

If I might chime in, the comment about 99.99997 being really one sig figure, is spot-on. Art's right. SBHarris 00:04, 22 January 2007 (UTC)

Earth's atmosphere. Wrong percentages?

The first paragraph says: It contains roughly 78% nitrogen, 21.12% oxygen, 0.93% argon ... These percentages sum up to more than 100%. It just seems wrong.

I suggest they should be changed them to: 78% nitrogen, 21% oxygen, 0.93% argon.

Also table on the right hand side, showing Nitrogen 75% seems incorrect. —The preceding unsigned comment was added by Cgeorges (talk • contribs) 18:58, 17 April 2007 (UTC).

Part of the confusion is that nitrogen is either 78% or 75% depending on whether you include water vapor and other variable components. A case can be made for measuring percentages of the non-variable (well, at least not so variable) components of the air only, so that the answers don't depend on humidity - there's more water vapor over the Amazon than over the Sahara, therefore there is a larger percentage of nitrogen etc. over the Sahara, just because the water vapor is gone. Also, a total including "roughly 78%" can add to more than 100% due to round off error. But I basically agree with Cgeorges that the confusion should be cleared up. Art LaPella 21:32, 17 April 2007 (UTC)

Please, someone who has knowledge/access to better references, PLEASE change the %s to add up to 100% in any manner that makes sense (e.g., include various ranges of %s for each component so that they at least COULD add up to 100%). Thanks!! philiptdotcom 03:17, 5 November 2007 (UTC)

Density and Mass

Has anyone noticed that according to the graph "NRLMSISE-00 standard atmosphere model" the temperature RISES beyond 80km altitude to reach an amazing 460 degrees Celsius (!) in 150km altitude. Can the people who posted this graph perhaps look into this again and correct this nonsense? —The preceding unsigned comment was added by 218.186.9.5 (talk) 09:05, 2 March 2007 (UTC).

The thermosphere article (and anything else I've read) agree that the temperature rises beyond 80 km: "Thermospheric temperatures increase with altitude...Temperatures are highly dependent on solar activity, and can rise to 2,000°C." Art LaPella 18:16, 2 March 2007 (UTC)

Yep. Don't confuse temperature with heat. It's very hot but there's not much of it, so it won't burn you. Think of the solar corona at millions of degrees. Such temperature inversions, with "vacuum" between to insulate them from conduction and convection, are possible. SBHarris 19:49, 2 March 2007 (UTC)

Composition

According to the Nasa Water Vapour Project reported at http://www.engr.colostate.edu/~ramirez/ce_old/classes/ce422_ramirez/CE422_Web/WaterVapor/water_vapor_CE322.htm the average precipitatable column of water over the globe varies from 22 to 27.5 mm. This converts to 0.34 to 0.43% water in the atmosphere by volume or 0.21 to 0.27 % by mass.

The mass concentration given for carbon dioxide is in error. Carbon dioxide being 51% denser than air must make it greater by mass composition than by volume. A straight molecular weight calculation (ignoring deviation from ideal gas) gives a result of 0.058 % carbon dioxide by mass. It is not clear to me that laboratories take into account the deviation from ideal gas when calculating carbon dioxide concentrations by volume.

Errors in calculating the mass of carbon dioxide in the atmosphere give rise to the frequently quoted statistic that only 50% of human emmissions are retained in the atmosphere. The true figure over the last 40 years exceeds 60% and has exceeded 100% in some years.

Chris Seymour 05:58, 20 March 2007 (UTC)

How can retention exceed 100%? Ottoump 16:50, 24 July 2007 (UTC)

And whether the water vapor is 1.0% or smaller, the stated composition "78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, trace amounts of other gases" sums up to 99.96%, .04% allotable to water vapor and the other mentioned trace gasses. Apparently the stated figures apply to a water vapor-free atmosphere?, regardless. the values obviously need to be righted and the description corrected to include the water vapor component. As was pointed out, the total composition components cannot exceed 100.00%. Radzewicz (talk) 23:56, 21 August 2008 (UTC)

, and a variable amount (average around 1%) of water vapor.

Average temperature

Are there any sources to establish that the average temperature at the surface is 15 C? I looked and every source I saw gave the number that used to be in this article, 14. If no one can cite a source for this, I will change it back. Mr.Z-mantalk¢ 06:30, 29 May 2007 (UTC)

Now it stands that it is 20C , seems to rise pretty quickly :-D. I'm going to delete the sentence, since it's obviously faulty. —Preceding unsigned comment added by 85.156.17.88 (talk) 04:45, 20 March 2009 (UTC)

Troposphere=

Many textbooks state that the reason that a rising air mass cools is because of the Joule Thompson effect. This is not correct. The JT effect can only account for 0.5 K of cooling in air originally at 1 bar and 300 K. The correct explanation is that a rising air mass does work adiabatically upon the surroundings, so its internal energy, hence temperature, decreases. This is the explanation for my edit of that paragraph. Dr Thermo 01:54, 6 June 2007 (UTC)

Troposphere 2

I appreciate the recent edit regarding the temperature profile in the thermosphere. I think I will stick to my guns regarding the reason for temperature drop. I changed the explanation from the Joule Thompson effect to work against the surroundings. Another editor changed this to work against gravity. I don't think this is correct. The air mass rises because of bouyancy. It takes energy to sink a bouyant body. The air mass expands as it rises becasue of lower pressure at higher altitude. When it expands, it does work by pushing back the surrounding air. The amount of work is given by w = -integral(pdV), negative because energy goes out, p is the pressure of the surrounding air, and V is the volume of the air mass. Before I edit, I will await comment here. Dr Thermo 20:15, 6 June 2007 (UTC)

Yes, of course you are correct about the basic reason for the adiabatic temp lapse. For a really good intro article which starts simple and goes into detail, see: [11], plus the link to hydrostatic equilibrium constraints. Of course, the gravitational gradient determines these lapse rates and the stable structures. In theory there need be no temperature lapse rate at all if a fluid packet does no PdV work on the way up or down, or else such work is compensated by heat input or radiation (non-adiabatic systems). But even for isothermal atmospheres, there must be hydrostatic equilibrium, and in that case different potentials in a field gravity, mg*dh, show up as differing VdP potentials in fluid packets at different h heights. No work is done here, but mg dh potentials and VdP potentials have to match, with altitude. The simplest of these relations is with ordinary incompressible fluids where PV = mgh or P = rho*g*h. But one needs this structure in gases also, to make sure that the pressure differences on each parcel of fluid (from top to bottom) are enough to keep them suspended (equal their weight), and that the pressure at any point equals the integral of all weights above it. So in the simplest ideal gas case you wind up with things like mg(dh) = nRT dP/P, which already gives you the approximate exponential pressure structure of our lower atmosphere. The article above has corrections for semi-adiabatic cases where thermal structures are semi-stable (don't change much over altitudes of interest), but still satisfy the hydrodynamic equilibrium equations everywhere, as they always must. SBHarris 00:35, 25 July 2007 (UTC)

The observations I make here are concerned with the global aspects of air pressure/temperature and do not take into account water content. Water content is a local matter, it is very variable from one location to another. Air pressure is fixed by gravity and atmospheric mass so it forms the true basis for analysing global effects. Water content effects are thus played out against a pressure profile defined by a background of dry air pressure.

I am not satisfied with this statement "When an air mass rises the pressure upon it decreases so it expands, doing work against the opposing pressure of the surrounding air"

The pressure gradient is along the gravity gradient, in effect vertical; if the expanding air was doing work against the "opposing pressure of the surrounding air" it would have to produce a movement tangential to the surface which would in turn cause a tangential pressure gradient against this movement. The net result should be a local increase in height appropriate to the increased energy in the parcel whereby some of the kinetic heat energy is transformed into gravitational potential energy, cooling the gas. Not all the heat energy is converted into potential energy, the heated air parcel will always be warmer than its surroundings and will rise steadily until thermal effects disappear due to the reduction of pressure at the top of the troposphere. This is of course the mechanism that drives the atmospheric circulation with its hadley, ferrel and polar cells.

I understand that the role of gravitational energy in the vertical temperature profile was proposed in a previous edit. I have looked but cannot find it, would someone be so kind as to indicate the relevant edit?. The role of gravity is central to the atmosphere, it is after all gravity that keeps it on the earth so it is entirely necessary that gravitational effects are included at every stage. Damorbel (talk) 19:59, 19 December 2007 (UTC)

Nobody has defended the idea that "When an air mass rises the pressure upon it decreases so it expands, doing work against the opposing pressure of the surrounding air", there is no horizontal force from the surroundings to do work against. When gas rises in the atmosphere the force it works against is gravity. The temperature of a gas is defined by its kinetic energy, as the gas rises some its kinetic energy is converted into gravitational potential energy which is non thermal, so its temperature drops. I have found the original explanation by contributor [way, the truth, and the light] for temperature decreasing with height, I am going to put it back, slightly edited to emphasise the change of thermal energy to gravitational potential energy (this corresponds to Galileo's observation of the trajectory of an object thrown upwards). This heating warms air masses, which makes them less dense so they rise. When an air mass rises, it does work against gravity. This work changes some of the thermal (kinetic) energy into gravitational potential energy, so the temperature of the air mass decreases. As the temperature decreases, water vapor in the air mass may condense or solidify, releasing latent heat that further uplifts the air mass. This process determines the maximum rate of decline of temperature with height, called the adiabatic lapse rate --Damorbel (talk) 12:56, 3 July 2008 (UTC)

100%

"This is complete nonsens [sic], because the first four compounds make more than 100%" I didn't write those words and they need more Wikipedia:Civility, but "Looks like someone can't add" isn't civil either, especially since he can add. 78.084% N₂ + 20.946% O₂ + 0.9340% Ar + 0.0383% CO₂ equals 100.0023%. There is indeed an apparent error. Art LaPella 20:55, 26 June 2007 (UTC)

The numbers match the NASA source used in the text, so it is apparently an externally originating problem. Dragons flight 01:19, 27 June 2007 (UTC)

Please, someone who has knowledge/access to better references, PLEASE change the %s to add up to 100% in any manner that makes sense (e.g., include various ranges of %s for each component so that they at least COULD add up to 100%). Thanks!! philiptdotcom 03:18, 5 November 2007 (UTC)

I would like to see some small explaining text below the table saying e.g. that these are the official composition figures from NASA or something similar. Thanks 130.238.197.149 (talk) 16:18, 8 February 2008 (UTC) (sv: Beryllium-9?)

Citation-request partial answer (std temperature)

I saw a line marked Citation Needed, "The average temperature of the atmosphere at the surface of Earth is 15 °C (59 °F).[citation needed]", and believe that I have a partial answer. As a pilot, we were taught to base all calculations off of the "Standard Temperature and Pressure", which is 15°C and 29.92"Hg at sea level. For all variations from that (i.e., higher altitude, warmer or cooler temp, higher or lower barametric pressure), one applied a formula (or consuted a table) to get adjusted factors for doing calculations such as true airspeed or density altitude.

I don't know if 15°C is the "average" temperature of the Earth's surface, but it is the "Standard Temperature" used by pilots and meteorologists as the basis for calculation. I'm sorry, I don't have a citation for this handy, although I suspect it's an easy Google search (which I would do, but I'm running late, right now.) I am aware (but also without citation) that there is an "alternate STP" based on an air temp of 0°C and some other pressure at sea level, but it is my understanding that this is to simplify the tables/calculations, rather than representational of real-world conditions.

I hope that's useful to someone looking to create a cite for that statement. Oliepedia 15:15, 13 August 2007 (UTC)

Picture Incorrect

I've notices that in the article a picture of the atmosphere showing the sections is missing one, it is missing the ionosphere which is between the mesasphere and the thermosphere. this could cause some confusion to people researching the subject. —Preceding unsigned comment added by 220.238.188.88 (talk • contribs) 10:19, 16 August 2007

Please see ionosphere for the relationship between it and the atmospheric layers. It is not between the other zones - rather an overlapping relationship. Vsmith 11:13, 16 August 2007 (UTC)

Variation in the thickness of Earth's atmosphere

Mountaineers are interested to know more about the variation in barometric pressure due to the varying thickness of the Earth's atmosphere. I think this thickness variation is due to centrifugal force effects of the Earth's rotation.

Specifically, mountaineers would like to know:

What is the variation in sea level barometric pressure between the pressure at the equator and:
a)10 deg latitude
b)20 deg latitude
c)30 deg latitude
d)40 deg latitude
e)50 deg latitude
f)60 deg latitude
g)70 deg latitude
h)80 deg latitude
i)90 deg latitude

DO ANY OF THE BAROMETRIC PRESSURE EQUATIONS TAKE LATITUDE INTO ACCOUNT?
Would the variation be about the same for the northern versus southern latitudes?

These pressure differences are related to items of interest to mountaineers such as:

Is the air less dense at the summit of Denali (20,320') than on Aconcagua (22,841') due to the higher latitude?

Chimborazo(20,000'+)is on the Equator in Ecuador. Thus it sits on the "bulge" caused by the Earth's rotation and is said to be the summit farthest from the center of the earth. Which effect is greater on the density of the atmosphere on Chimborazo: the "height" due to the bulge, or the greater thickness of the atmosphere at the Equator? In other words, would the air on Chimborazo be less dense if it were located at higher latitude?

On a high summit, say 20,000', would the air be more dense on a cold day or a warm day? (It would seem that if it were warm, the atmosphere would expand and more air would be above you so the pressure would be greater. Conversely it would seem that on a cold day, the air would be dense and would contract, thus more of the total atmosphere would be below your 20,000' location and so the pressure would be less at your 20,000' location.)

Can someone add more info on this topic to the main article? Ice axe 2 02:22, 30 August 2007 (UTC)--Ice axe 2 02:22, 30 August 2007 (UTC)

[12] and [13] confirm that effect, but don't quantify it. Art LaPella 00:10, 31 August 2007 (UTC)

Ah ha! I found some data on page 8-8 in the 19th edition of Cameron Hydraulic Data by Flowserve. It has a table for Correction of Mercurial Barometer for Latitude in Inches Hg to Reduce to 45 deg Latitude. 71.111.55.34 22:50, 15 September 2007 (UTC)

Noinclude

This edit introduced the stray word "noinclude" near the bottom of the article. I don't know why it's in Template:Atmospheres. Art LaPella 02:15, 3 September 2007 (UTC)

Resolved

 – Art LaPella 00:09, 4 September 2007 (UTC)

Conflicting atmospheric mass figures

Earth's atmosphere#Pressure and thickness now says "total atmospheric mass is 5.1361×10^18 kg [14]." But Earth's atmosphere#Density and mass still says "According to the National Center for Atmospheric Research, 'The total mean mass of the atmosphere is 5.1480×10¹⁸ kg with an annual range due to water vapor of 1.2 or 1.5×10¹⁵ kg...'". Art LaPella 00:09, 4 September 2007 (UTC)

Good catch. The 5.1361 number came from a 1988 paper, the 5.1480 number from a 2005 paper (with some overlap of authors). About a .23% increase. I've updated the article accordingly. --Vaughan Pratt (talk) 07:17, 30 May 2008 (UTC)

Thank you. Art LaPella (talk) 02:04, 31 May 2008 (UTC)

Merge Proposal

The page Air used to redirect here but someone recently changed it to be its own (stub) article. Why was this page not just left as a redirect? The Earth's atmosphere article is quite good. I propose we remerge them.Jyuichi 05:25, 7 September 2007 (UTC)

I think you're right. I've been bold and just done it. There was nothing to merge as far as i could see William M. Connolley 10:07, 7 September 2007 (UTC)

What I was going to do was translate de:Luft, which is a good article. I think there is a place in Wikipedia for an article about air.- Gilliam 05:35, 9 September 2007 (UTC)

I understand what you are trying to do but air is essentially defined as "the earth's atmosphere" so it might be better to incorporate the information from de:Luft in to this article, see Wikipedia:Translation. Jyuichi 23:43, 9 September 2007 (UTC)

I think it's a mistake to redirect Air to Earth's atmosphere. I understand that the historical reason for it, but conceptually they should be fairly different articles, even though they cover a lot of common ground (i.e., air is what we breathe and so is Earth's atmosphere). Air should probably reflect more about the history of our understanding of the stuff we breathe as well as our cultural constructs around it (association with earth/fire/water, association with wind, association with the sky, spirits, etc.). This article, on the other hand should focus more (as it does) on the chemical/physical properties of our atmosphere, how it relates to life on earth, how it has changed over the course of our planet's history, and how it compares to other planets. It's kind of strange that we are one of the only major wikipedias not to have an article on Air. (The German wikipedia is not the only one to have separate articles for air and Earth's atmosphere. So do the French, Spanish, Italian, Japanese, Chinese, Russian, and Portuguese Wikipedias, among others. (The Korean Wikipedia, on the other hand, follows our model).

If we don't want to have separate articles for them, we should probably move this one to Air, the much better-known name for this topic. After all, Sun is Sun and not Earth's star. Jun-Dai (talk) 18:21, 14 March 2008 (UTC)

Temperature Mesosphere

It says in the article that the temperature of the Mesosphere increases with the height. I assume it should state decreases? BillHicksRulez 00:29, 27 September 2007 (UTC)

I agree. After consulting the graph at Earth's atmosphere#Density and mass, Mesosphere, and its reference, I changed "increasing" to "decreasing". Art LaPella 02:01, 27 September 2007 (UTC)

The Noble gasses

The page on the Noble gasses says 'Eventually all the known noble gases except for helium were discovered in the air'

Then how Radon is not in the chart. —Preceding unsigned comment added by 86.143.7.146 (talk) 07:50, 27 September 2007 (UTC)

101,00483 percent ??

if you add up all the percentages from the table at the right, you get 101,00483 percent. That does not make any sense :b q: Crakkpot (talk) 20:36, 18 February 2008 (UTC)

It's probably got something to do with how it say's the air is about 1% water vapor. Although granted, 101.004883% is more than 1% over 100, so the exact percentage of water vapor would actually have to be -0.00483% in order to add up to exactly 100.--Foot Dragoon (talk) 01:47, 19 February 2008 (UTC)

Carbon Dioxide and parts per million

How many parts per million does carbon dioxide need to gain to cause an increase in percentage? What i mean is, what is the relationship between percent of atmospheric gas content, and parts per million? would say, 1000 ppm be 0.01% of the atmosphere? RingtailedFox • Talk • Contribs 03:24, 2 March 2008 (UTC)

If you're comparing apples to apples (that is, not confusing percent by mass with percent by volume), then your question is about arithmetic. Percent means parts per hundred, so 1000 ppm (parts per million) is 1000 millionths, or 1 thousandth, or 1 tenth of a hundredth, or 0.1% (not 0.01%). Art LaPella (talk) 05:34, 2 March 2008 (UTC)

Yes, i am trying to compare apples to apples, as you said. I understand percent as parts per hundred (pph). thanks for clarifying things for me :) RingtailedFox • Talk • Contribs 18:26, 2 March 2008 (UTC)

Average air mass and pressure

Both the mass of the atmosphere (5148.0 teratonnes) and the area of the earth (51007.2 megahectares) are known to impressively high accuracy, from which we can deduce the average mass (not to be confused with weight) of air over a square meter of the earth's surface equally precisely as 10.093 metric tonnes, which I've just now pointed out in the article. However this has got me to worrying about how this is reconciled with the standard atmospheric pressure of 101.3 kPa. The assumption of a constant gravitational force of 9.78 N/kg at all altitudes should give an average pressure of 98.71 kPa, 2.5% below the standard, and even lower when one factors in lower gravity and higher centrifugal force at higher altitudes. The only explanation I could come up with is that centrifugal force also tends to push the atmosphere away from the poles to the equator, creating enough variability to make a 2.5% discrepancy part of the overall noise. Is that the explanation, or is there something else going on here? --Vaughan Pratt (talk) 07:00, 30 May 2008 (UTC)

Standard atmospheric pressure is an historical convention chosen by mid-latitude scientists to represent typical sea level pressure. I'm not at all surprised that it does not represent an actual average of the pressure over the surface of the Earth. Dragons flight (talk) 02:47, 31 May 2008 (UTC)

Well I'm surprised. I'd be ok if it were off by a fraction of a percent, but 2.5% seems excessive. I worried about this for a while until it dawned on me that the land above sea level was displacing sufficient air to raise the atmosphere significantly. Using a commonly cited estimate of 840 m for the mean elevation of the earth's land mass (which I assume is defined as the volume of land above sea level divided by the Earth's land area of 148.9 Mm²), the air so displaced comes to .125 Mm³, or 138 teratonnes based on a mean density of air of 1.1 kg/m³ at a mean altitude of 420 m. Redoing the math assuming 5148+138 = 5286 teratonnes of air gives 101.3 kPa, right on the nose! The 98.71 kPa figure should thus correspond closely to the atmospheric pressure at the mean elevation above sea level of the bottom of the atmosphere, rather less than 840 m when the area of the oceans is factored in, namely 840*148.9/510.07 = 245 m. (I was also bothered by the contributions of the earth's oblateness and centrifugal force, but it seems reasonable to assume these cancel exactly on the assumption that centrifugal force bulges the earth and the atmosphere out to the same degree.) --Vaughan Pratt (talk) 05:40, 5 June 2008 (UTC)

Pressure and thickness

Under this heading in the 3rd paragraph is written "Were atmospheric pressure to remain constant with height the atmosphere would terminate abruptly". The concept of the pressure remaining constant with height is so odd I assume it is an inadvertent error and pressure should read density. I will change it.--Damorbel (talk) 15:23, 19 June 2008 (UTC)

ppmv

I rewrote the explanation of ppmv in the article. Please check it for accuracy. I am not certain that I am correct.

I did not understand the use of ppmv (and may still not).

The table of abundances gives ppmv. When I clicked on the wikilink it took me to the Parts-per notation article which does not say one word about ppmv and why the composition of the atmosphere is measured this way. Further a Google search of the web turns up nothing (how strange).

After sleeping on it I decided that ppmv depended on the ideal gas law applying to the atmosphere. I decided that ppmv was the same as the molar-fraction at the precision given. I do not know that this is correct.

Then I finally notice that there was an explanation of ppmv in the article. Bad. It should have been linked to the table. So I did that.

Thanks,

Nick Beeson (talk) 14:28, 18 August 2008 (UTC)

Work against gravity

I have reverted todays edit by [[15]]dragonsflight. Dragons_flight changed an edit of mine, I have been unable to find an explanation of his edit which ghanged the entry back to a previous, weak explanation. The matter is of some importance in that the only force acting on gas in a stationary atmosphere is gravity, there are no horizontal components other than the kinetic interactions with ajacent molecules but since the incremental change in volume from horizontal movement of rising gas is negligible, the change in volume is effectively that of height change. This change of volume was not properly indicated in the original edit and I will revise it to prevent misunderstanding. My intention is to make it clear that the change in temperature with height has two components, the work against gravity when the gas ascends and the work lifting the gas above a given parcel as its volume increases.

Ha! dragonsflight that was a quick undo! Your reference to http://en.wikipedia.org/wiki/Adiabatic_cooling is irelevant o an atmosphere since it does not include the component of gravity I mention above. Please undo your reversion or establish why gravitation is not important--Damorbel (talk) 17:28, 28 August 2008 (UTC)

There are two forces acting in a stationary atmosphere. In an incremental height of the atmosphere, dh, the difference in pressure between the top of an air packet and the bottom, P(h) - P(h+dh), gives rise to upward force. In a stable atmosphere, this exactly cancels gravity and the air packet neither rises nor falls. See bouyancy. In an unstable atmosphere, the pressure difference does not equal the gravitational force, but nonetheless is cancels most of the gravitational force. The residual net force is what causes the air packet to rise or sink, and the work done by external forces on the air packet is not the work done gravity but rather the work done by the net force. Since the pressure gradient mostly cancels the gravitational force, the change in potential energy due to change in altitude is much less than you would expect if you consider only the gravitational term.

Further, the net change in the internal energy of the gas is dominated instead by the approximately adiabatic volume change that occurs as it moves from one pressure regime to another. Against this the change in internal energy due to the net external forces is generally neglible. Hence the change in temperature as air packets change altitude is controlled by the response to the change in external pressure, and not the effects of gravity. Dragons flight (talk) 18:01, 28 August 2008 (UTC)

I understand what you say, but your concern for gravity is only relevant to the dynamics of the packet of air, i.e. how it responds to a displacement. For a complete picture you must account for the static potential energy acquired by the air when raised to an altitude z. A mole of air at ground level has energy P1V1=RT1, reduce the pressure, expanding it adiabatically at ground level and cools, it has a new volume V2 and pressure P2 and its temperature drops to T2 according to the non gravitational adiabatic law you refer to. In reality this mole of atmospheric air is no longer at ground level, it has expanded upwards and thus work has had to be done against the force of gravity to get it to its new altitude. The situation is comparable to Galileo's stone thrown upwards with a vertical velocity v. The stone's initial velocity takes it upwards, it has kinetic energy 1/2mv^2. The stone's vertical velocity reduces because gravity acts on it. At some height h v becomes zero, the stone obviously has zero kinetic energy, all its kinetic energy has now been converted to gravitational potential energy = mgh. As the stone falls its velocity increases and it recovers its kinetic energy.

The kinetics of atmospheric gas is exactly comparable, the air at ground level has a temperature T thus it has a mean velocity v. According to the kinetic theory of gases it collides with the ground and rebounds, the pressure on the ground is measurable. If it rebounds vertically it will not collide with a solid surface but will lose its vertical velocity from the effect of gravity, just like the stone. In reality at the density of the surface atmosphere the molecule that collided with the surface will, after rebounding, collide with another molecule but with reduced velocity. As you follow the molecules higher and higher their velocity, thus their temperature, reduces.

Most courses teaching the gas laws ignore the effect of gravity. When considering the atmosphere this is not possible because gravity is the only force keeping the atmosphere in place! This was the purpose of my edit, the one you reverted. The error of forgetting gravity is quite common and leads to some very odd results. --Damorbel (talk) 20:56, 28 August 2008 (UTC)

Gravity is central to determining the pressure and density gradient:

${dP(h) \over dh}=-\rho (h)g$ and $P(h)\varpropto \rho (h)T(h)$

However, those gradients entirely incorporate the effect of molecules losing energy as they bounce higher. Once you appreciate this large scale effect, one can also recognize that the force of gravity is locally balanced by the bouyant force of interacting with other air molecules. It's not an error to ignore gravity, because the effects of gravity are already baked into the pressure changes that the air parcel experiences. It is the recognition that gravity is already implicitly included in the pressure change that allows one go further and realize that the adiabatic pressure change alone is sufficient for understanding the change in temperature. If you had a tabletop experiment that allowed you to adiabatically vary the pressure on a packet of air in the same manner as it varied while rising through the atmosphere, then you would witness the same temperature change even without varying the height. Dragons flight (talk) 21:58, 28 August 2008 (UTC)

Your argument is not clear. The reference to adiabatic cooling that you give (in the history!) [[16]] is good as far as it goes but it is not sufficiently precise to identify the matter of thermal gradient in a planetary atmosphere. The reference says Adiabatic heating occurs when the pressure of a gas is increased from work done on it by its surroundings, ie a piston. In the case of the atmosphere the only force that the air works against is gravity. Should a packet of air be heated instantly for some reason, a small part of the atmospheric mass increases in volume, the only force acting on this mass is gravity, there is no cylinder as in a diesel, you could imagine that the air above it is a piston but it doesn't move solidly like a piston, the heated mass of air rises rather like a bubble.

If, as the article currently states, it expands, doing work against the opposing pressure of the surrounding air it would only be temporarily true because it would create a pressure wave that would disappear at the speed of sound. Although the heated air has now expanded (adiabatically) it is still warmer and less dense than the adjacent air and hydrostatic forces will cause the warmer to rise adiabatically against gravity.

I do hope you see the key role that gravity plays, it is the only force that confines the atmosphere therefore any analogy with pressure from pistons, cylinders and "opposing pressure of the surrounding air" must ultimately fail.--Damorbel (talk) 08:31, 9 September 2008 (UTC)

Adiabatic Lapse Rate, Dry (you will also need to click the link with the same name on the displayed page) explains how to derive the adiabatic lapse rate for any planet. Note that the planet's gravitational constant is an important part of the derivation.

Your arguments are also a little backward - assuming that hot air rises is like sucking a drink through a straw. It is well known that once the straw is long enough (about 20 feet) the water will not go any higher. This is because air PUSHES the water up the straw. In the case of the atmosphere, heavier cold air sinks and pushes the warm air up. Your argument ignores the sinking cold air. Also, the "pressure wave" does not "disappear at the speed of sound" because the temperature and density of adjacent air masses are different. In this case, the warm air mass must be pushed into a new position where its temperature AND density match the surrounding air masses - 5 miles per hour is fast for this to occur.

For a concrete example, think of a weather balloon filled with helium. To start with, only a part of the balloon contains the gas, the rest of the balloon is limp with no *internal* pressure. It will take several minutes for this to rise and expand. Q Science (talk) 06:20, 25 September 2008 (UTC)

Kyoto Protocol

This protocol has little or nothing to do with an article describing the atmosphere, there is enough information already available about the Kyoto Protocol so I deleted the contribution--Damorbel (talk) 11:56, 23 September 2008 (UTC)

Well let's hope this doesn't turn into an editing war because User:Aid85 has just added it back. HumphreyW (talk) 16:12, 16 October 2008 (UTC)

Source of Oxygen

There are several competing theories for the source of the Earth's oxygen

• Plants
• Sunlight converting water into Hydrogen and Oxygen
• Oxygen is observed in interstellar space, and the Earth simply trapped some

For plants to be an important contributor, shouldn't there be more coal and oil than there currently is. Specifically, if plants are the source, then burning ALL the fossil fuels should use up 3 or 4 times the available oxygen. It seems like sunlight breaking down water makes a lot more sense. Q Science (talk) 06:32, 25 September 2008 (UTC)

Scale Height

If the pressure decreases by 50% every 5.6 km, then why does the article says that it also decreases by 36.8% every 7.64 km? I think the value should be (1-.368) -> 63.2%. The wiki page explaining Scale Height also appears to be wrong (I think).

Wolfram says that Scale Height is

The height in the atmosphere where pressure is 1/e times its value at the surface.

Q Science (talk) 06:50, 25 September 2008 (UTC)

I agree this is confusing. I think this is one of those things where, when you already know what the author meant, it makes sense -- which is utterly useless for those of us who read the encyclopedia because we don't already know :-).

Here I think the author is trying to express the fact that when the pressure is P at some altitude, then when we go up 5.6 km the pressure is about P*1/2, or equivalently when we go up 7.64 km the pressure is about P*1/e = P*0.368.

Alas, translated from mathematical symbols into English it sounds weird -- "the pressure is multiplied by 1/e = 0.368 every rise in 7.64 km".

That sounds obviously wrong, because "multiplied" implies a bigger number, but we know higher altitudes have a smaller pressure.

The authors of this article (and the "scale height" article) are using "decreases by" as a synonym for "using the × button on your calculator" (multiply) -- since "decreases" gives the correct implication that the result is a smaller number.

Alas, it has the ambiguity you pointed out.

I'm not sure that saying "the atmosphere decreases by 1-1/e = 63.2% every 7.64 km" is really an improvement.

Since 2*63.2% > 100%, it could be incorrectly misinterpreted to mean that the pressure decreases to zero somewhere below 2*7.64 km = 15 km. Since 2*50% = 100%, it could be incorrectly misinterpreted to mean the pressure decreases to zero at exactly 2*5.6 km = 11.2 km.

Also, I hate making things unnecessarily complicated -- telling people to multiply the pressure P by 0.632 to get 63.2%, and then subtract that from P -- which is more complicated than telling people to multiplying the pressure P by 0.368.

What could we do to make this article easier to understand?

Would saying "decreases by a factor of 1/e = 0.368" help, or just make it more confusing?

Would it help to reword it to describe descending in the atmosphere -- "as you descend in the atmosphere, the pressure multiplies by e = 2.72 for each 7.64 km you descend"?

--68.0.124.33 (talk) 16:09, 31 October 2008 (UTC)

I don't think its confusing. But I do agree its wrong. It should read "to" not "by"; or "to 1-1/e" William M. Connolley (talk) 20:46, 31 October 2008 (UTC)

Kyoto Protocol

Unless someone can give me a compelling argument as to why the section on the Kyoto Protocol is in this article, I am going to suggest that it be removed. It is a controversial topic that really does not have much to do with the atmosphere per se. 65.167.146.130 (talk) 16:04, 31 December 2008 (UTC)

Agree. Also, arguably, the air pollution just above it. But preserve links to both William M. Connolley (talk) 16:15, 31 December 2008 (UTC)

As there were no compelling reasons offered to keep this section (or indeed any reasons of any kind offered), I have removed this section. 65.167.146.130 (talk) 21:54, 8 January 2009 (UTC)

Temperature at the surface

The article currently states that the average temperature at the surface of the Earth is 20°C. I was going to fix it, but

• The first reference says 13.9 °C (57.0 °F; 287.0 K). Earth's Radiation Balance and Oceanic Heat Fluxes

• The second reference (Lawrence Livermore National Laboratory - LLNL) is a plot that appears to represent the results of several models. These indicate that the temperature is between 11 °C (52 °F; 284 K) and 17 °C (63 °F; 290 K). Coupled Model Intercomparison Project Control Run

• The standard value from NASA is 15 °C (59 °F; 288 K). Earth Fact Sheet

Base on these, perhaps it is safe to say that the average temperature is basically unknown. At any rate, I thought it would be good to request comments before making a change. Q Science (talk) 01:51, 19 January 2009 (UTC)

GISS discusses this here, especially in the last question. Dragons flight (talk) 02:06, 19 January 2009 (UTC)

Does the average surface temperature even mean anything??? I mean there is such a variance that the telling the average is pretty useless. Its like trying to say the average altitude of the USA, which is very different depending on whether you are in Florida, Colorado or Central Alaska. Maybe something like stating the average temperature at a few specific locations would be more useful? 65.167.146.130 (talk) 20:10, 20 January 2009 (UTC)

It's useful if you want to calculate basic global things, such as we were recently using the number in my Land-Atmosphere interaction class in regard to radiant fluxes and wavelength of radiation given off by the earth. If nothing else, it's good to have a number as an example. Mailseth (talk) 20:46, 20 January 2009 (UTC)

Abundance of Particles

Can anyone provide the average abundance of particles that are present in each layer of the Earths atmosphere? I think this would be very useful and informative data.

—Preceding unsigned comment added by Dankelly83 (talk • contribs) 16:18, 22 January 2009 (UTC) 

---

question I have always wondered about.

Air is a mixture of O2, N2, Ar2 and other stuff. Why don't these gases form layers? Why does the heavier Ar2 not completely sink to the bottom? That would push all the O2 up a bit, so that places like death valley and the dead sea would be full of Ar2 and their air unbreathable? 65.167.146.130 (talk) 20:07, 5 February 2009 (UTC)

First, it is Ar, not Ar2. In the extreme upper atmosphere, these do separate to some extent. However, in the lower atmosphere wind keeps everything mixed up. Even in a basement with no wind, the air is warm enough that the various gases don't separate.

H2O - 18 : N2 - 28 : O2 - 32 : Ar - 40  : CO2 - 44

The fact that water is much lighter than everything else helps to explain why low pressure systems are associated with rain. Basically, assuming the same temperature and the same number of molecules per unit volume, the more water there is, the less the "air" weighs. As a result, the air containing water rises and, at a lower temperature, creates clouds. Notice, however, that the water vapor stays well mixed until it begins to condense. The water vapor does not rise, instead the entire air mass containing the water rises. Q Science (talk) 22:36, 5 February 2009 (UTC)

On no separation, correct. On rain, wrong William M. Connolley (talk) 22:41, 5 February 2009 (UTC)

There's nothing like wanting to point to another article only to find it's crap in need of work. -Atmoz (talk) 22:54, 5 February 2009 (UTC)

Please explain "on rain, wrong". Q Science (talk) 23:06, 5 February 2009 (UTC)

Atmosphere history replaced

Since there was a version of the atmosphere's history which was referenced on the paleoclimatology article, I replaced the unreferenced version on this page with that version and removed the ref tag. Honestly, this should probably have its own subarticle, but I'm busy with wind and low pressure systems articles for the time being. Thegreatdr (talk) 17:57, 23 April 2009 (UTC)

Composition section Lifted from absolute astromony ?

The section on composition is almost the same as in the link below

http://www.absoluteastronomy.com/topics/Earth%27s_Atmosphere

The question is who copied who or could it be the same author ? —Preceding unsigned comment added by 124.176.183.185 (talk) 11:41, 8 May 2009 (UTC)

looks to me as if the lifting was done from WP to the website. Note the section:" ... at an altitude of about (not far from the mesopause)," which is the same as here but omits the actual measurement (and makes the statement rather strange). TheresaWilson (talk) 11:54, 8 May 2009 (UTC)

See also & External links are also (almost) identical, I'd say it's copied from here. TheresaWilson (talk) 11:57, 8 May 2009 (UTC)

Temperature and layers: temperature feeling?

I replaced the sentence "Although the temperature can rise to 1500, a person would not feel warm because of the extremely low pressure." by "The temperature of this layer can rise to 1,500 °C (2,730 °F)." Talking about what a person would feel doesn't make any sense, any human would immediately explode/die at the low pressure of that altitude. Using a space suit of course would completely change the discussion. What happens due to the very low pressure is that it is much easier to cool down the space suit because you have to evacuate much less energy per unit time (much less molecules hit the suit per unit time, but they still hit it with a very high energy each one!). Temparature has a clear physical definition, what a person "feels" doesn't...

Aog2000a (talk) 23:18, 9 May 2009 (UTC)

Suggested restructuring of "Structure of the atmosphere"

Starting with this 20 August 2009 edit, a significant number of changes were made to the "Structure of the atmosphere" section. One of the changes was to combine the text describing the tropopause, stratopause, and mesopause layers with the text for the similarly named layers which are below them in the atmospheric column. The logic appears to be that these are simply the names of the boundaries between two real layers. I suggest that that assumption trivializes the real situation. For instance, the troposphere is the lowest layer of the atmosphere and it is between 7km and 17km thick. The tropopause is also a distinct layer of the atmosphere between 1 km and 10 km thick. It is my opinion that any layer of the atmosphere that is 10 km thick is not simply a boundary between two real layers, particularly when the tropopause is thickest when the troposphere is the thinnest. In addition the lapse rate and chemistry of the tropopause is significantly different than the two layers it separates. In the published literature, there is additional confusion since many papers (but not all, and probably not even most) refer to the tropopause as the lower stratosphere.

Similar arguments of thickness, temperature profile, and chemistry apply to the other two layers.

In addition, I suggest reordering the paragraphs to match the order in the adjacent picture. That seems more logical (but only because the picture is there) and it is the order that was used before August 2009.

I suggest using the chart in International Standard Atmosphere as a guide.

Q Science (talk) 09:30, 23 September 2009 (UTC)

The current presentation follows standard practice in the field. The "pauses" are not regarded as layers in themselves but as the boundaries between layers. See any number of standard textbooks in weather and climate (Ahrens; Aguado and Burt; Holton; etc). The layers also are presented from lowest to highest, whether a graphic is included or not. Short Brigade Harvester Boris (talk) 18:10, 23 September 2009 (UTC)

The American Meteorological Society textbook Weather Studies by Joseph Moran says (in the glossary, p 491)

Air temperature in the lower part of the stratosphere is constant with altitude

The IPCC usage of the term "tropopause" agrees with this. However, every standards-based definition I have seen (except the 1957 WMO definition) defines the tropopause as that layer between the troposphere and the stratosphere where the temperature is constant with altitude. So either the various US and international standards are wrong, or the textbooks (and the IPCC) are wrong. Typically, I prefer standards. Perhaps something should be said in the article about how various references completely disagree on the definition. (Actually, the IPCC may be using both definitions and just not bothering to indicate which one is being used.) Q Science (talk) 20:56, 24 September 2009 (UTC)

Why the ISS needs sails

While the "layers" approach to the atmosphere has its points, reading top to bottom you learn that the International Space Station orbits three layers of atmosphere down from outer space, where the atmosphere is hot enough to melt Aluminium. Another couple layers down you see that the pressure is only a kilopascal, you wonder what it might have been where the ISS is. Wonder on! Since meteors burn up very near the ISS, you assume the atmosphere is dense enough to have some effect. At 1773K and 1 kilopascal, if adiabatically compressed to 1 atmosphere it would have a temperature over a megakelvin! It's worth noting that the concept of "temperature" in such dispersed gasses is stupid.

It's also completely confusing and self contradictory. For instance we learn that's we'll learn about 5 layers presented highest to lowest, except that the ionosphere is part of the thermosphere. Wha?

• Exosphere: 310 mi to 620 mi.
• Ionosphere: 31 mi to 620 mi. "typically overlaps both the exosphere and the thermosphere."
• Thermosphere: 50 mi to 400 mi.

it's like an essay written by a bunch of people who don't bother reading each other's contributions.

Speaking of essays written by fifth-formers, check out Emission:

Emission is the opposite of absorption, it is when an object emits radiation. Objects tend to emit amounts and wavelengths of radiation depending on their "black body" emission curves, therefore hotter objects tend to emit more radiation, with shorter wavelengths. Colder objects emit less radiation, with longer wavelengths.

Which is mighty useful I suppose if you knew what any of those jargon terms ("black body", etc.) meant, and yet had no clue what they meant (because it's trivial and obvious info).

Wouldn't it be great if we deleted the boilerplate child's essay crap and just put a link to something like Emission (electromagnetic radiation). —Preceding unsigned comment added by 76.126.215.43 (talk) 02:42, 9 July 2009 (UTC)

Be BOLD and improve the article yourself. Everyone is a Wikipedia editor. Fix what you feel is wrong, properly Cite your sources and save yourself the headache of writing the above. Oh, and sign your talk page entries. - Ageekgal (talk) 17:37, 6 September 2009 (UTC)

It's not clear to me what needs improving here. You may be misreading the article, which breaks the atmosphere down into five principal layers determined by temperature. The ionosphere is not one of those layers, instead it is one of the layers determined by other properties, as the article makes clear.

The upper 2-3 layers, namely the exosphere, the thermosphere, and some indefinite portion of the mesosphere, are more exposed to ionizing solar radiation and are therefore collectively called the ionosphere. The ionosphere "takes the ionization bullet" for the stratosphere and troposphere, which are not ionized by radiation and are therefore considered below the ionosphere.

Regarding the section on Emission, Wikipedia is written for the well-educated adult, the same audience Britannica targets. Those finding any given Wikipedia article overly technical may find that Simple English Wikipedia meets their needs better. In particular its article on the atmosphere should be a relatively easy read. --Vaughan Pratt (talk) 18:30, 24 November 2009 (UTC)

What the relation between the Atmosphere on Earth and Earth's Magnetosphere, that which redirects or simply blocks major asteroids from impacting the planet? —Preceding unsigned comment added by 75.59.255.3 (talk) 11:11, 22 December 2010 (UTC)

Volcanos and global cooling

Speaking of volcanos, Mt. Pinatubo was the only colossal in the past 95 years; the period from 1783 to 1912 saw four colossals and a supercolossal (worth at least 10 regular colossals by itself). Not all in the same category are the same size. Mt Pinatubo was obviously a dwarf compared to fellow colossal Krakatau. Consequently the 1800s saw vast global cooling, years without summers, etc., which we are pulling out of gradually in the 20th and into the 21st century.

Given some more large eruptions or nuclear war, global cooling will come back, so technically it is within human power to affect. Get to it! But don't imagine humans are ready to equal the volcanos. 140,000,000,000 metric tons? And that's just Tambora.

I know it's a religious topic, not expecting you to repeat anything but the party line (or the never-self-censoring newspapers and journals ;)

Just like to put the well known facts out there occasionally, though I know they have no place in the consensus reality of Wikipedia. You will never win the war against partisans! Assuming that's the war you're fighting...

True enough: aerosols cool, greenhouse gases warm. Regarding the former, volcanos don't run on a sufficiently reliable schedule to entrust cooling to them, and besides what's so great about a sky full of soot? Regarding the latter, when you do the math it turns out that the CO2 output of the average volcano is equivalent to the CO2 breathed out by 400,000 people. At any given time there are some 1,500 active volcanoes, so a population of 600 million breathes out the same amount of CO2 as the world's volcanos, averaged over time over all volcanos including the very occasional colossal. This population was reached around 1700 AD. There now 6 billion humans, so human breath is ten times volcano production of CO2. Of course human breathing is not the whole of anthropogenic CO2 by a long shot. The section "Comparison of CO2 emissions from volcanoes vs. human activities" halfway down the page at the US Geological Survey website estimates that "Human activities release more than 130 times the amount of CO2 emitted by volcanoes." Also see the article Not even close! to see just how wrong Martin Durkin was about volcanic CO2 production in his movie The Great Global Warming Swindle. --Vaughan Pratt (talk) 18:44, 24 November 2009 (UTC)

Carbon Dioxide as "Air Pollution"?

This is a little far-fetched. There are a huge number of environmental benefits to the existence of CO2 and room for much more in quantity. It's not pollution. --82.43.47.6 (talk) 22:33, 18 February 2008 (UTC)

We're actually very near the minimum for photosynthetic plant survival. Bring it and the heat up some more, we free a lot of moribund farmland and what we have becomes more productive. These are good things, and if they're inevitable it's time for the low-lying coastal lands to start planning instead of ineffectively yelling about autos. Invest in fishing futures. Remember the current CO2 content of the atmosphere is 0.004%. If it races up to 1% it's a big problem, and if it hits 10% we all die. But if it only goes up 2.5 times to 0.01% it's good for the biosphere and only a problem to those who think protest accomplishes anything. Good luck with that!

I support this question and I am looking for a change. I suggest that this is not the place to consider the thermal effects CO2, but when you consider CO2 it is essential for life processes on the surface, and probably the subsurface, to classify it as pollution is clearly POV.--Damorbel (talk) 15:08, 19 June 2008 (UTC)

Further thought, according to the greenhouse effect the CO2 content of the atmosphere keeps us all from freezing to death, a tough task. Together with its very real function (see above) it appears to be a very vital form of "pollution".--Damorbel (talk) 15:37, 19 June 2008 (UTC)

As usual, it's a question of the amount. Even O2 is poisonous above a certain level. Looking at reliable sources is the answer. New scientist considers CO2 emissions as pollution[17], as does the New York Times[18], the Globe and Mail[19], and Nationmaster[20]. --Stephan Schulz (talk) 16:59, 19 June 2008 (UTC)

New Scientist? New York Times etc.? These might be thought of as good sources if they gave an explanation but the links do not reveal any reason for classifying CO2 as a pollutant. Citing O2 as poisonous is stretching the matter beyond its elastic limit since the observed effect seems to be the pure gas above atmospheric pressure [[21]]. CO2 is used to stimulate plant growth [22] in this case roses but it is quite easy to find cases where used to promote the growth of vegetables (food!). True enough, CO2 above 10% produces strong symptoms [[23]] but at 0.038% it is a bit early to panic.--Damorbel (talk) 09:50, 3 July 2008 (UTC)

Adding millions of tonnes annually of CO2 to the atmosphere might be nice for plants, etc., but could well change the balance of acidity in many oceanic habitats; coral bleaching events et al. seem to be correlated with these historically more acidic times. I would counsel caution in defining anything as pollution or not- an excess of anything can be considered pollution; see your email inbox for an example of when something nice (say, funny pictures of cats) can become a problem in excess (when everyone you know is sending you them and won't stop). More worryingly, the statement: "While major stationary sources are often identified with air pollution, the greatest source of emissions is actually mobile sources, principally the automobile[citation needed]. " -- this needs to go, it is demonstrably untrue. If you are talking about man-made pollution, industrial and farming sources far outweigh vehicle sources; if you include natural sources then volcanic outgassing is a major contribution far in excess of vehicles and even on a par with industrial sources. 24.5.174.212 (talk) 11:48, 21 October 2008 (UTC)

"Adding millions of tonnes annually of CO2 ...". There are about 2x10^12 tons of CO2 in the atmosphere, about 4000 tons for every man woman and child on the planet. How is it that mankind is going to change this sufficiently alter the acidity of the oceans and to bleach coral? What makes you think that even this amount of CO2 is sufficient to change the oceans acidity? If you are going to counsel caution let it be for a good reason, otherwise you just may make people frightened without a reason. --Damorbel (talk) 08:23, 20 December 2008 (UTC)

Sorry, but mankind is doing it in a number of ways, but primarily by burning fossil fuels. Atmospheric CO2 has risen about 35% in the last 150 or so years, and there is no doubt that the excess CO2 is anthropogenic. As a result, the equilibrium between ocean and air shifts, making the top layer of the ocean absorb more CO2. That CO2 turns into carbonic acid in solution and leads to ocean acidification. This is all well-known. Much of it is primary school chemistry, and none of these facts is in any way controversial, except maybe among a very small fringe.. --Stephan Schulz (talk) 08:43, 20 December 2008 (UTC)

Could you explain how much CO2 has to be absorbed to change the acidity of the sea? The sea contains large quantities of materials, notably calcium, that fix its pH because they are not fully ionized. Because you say "the equilibrium between ocean and air shifts" you give the impression that the pH of seawater is determined by the concentration of CO2 in the atmosphere. In fact the pH of seawater is determined by the dissolved salts see here [Buffering agent] and here [Buffer_solution] A none Wiki link is [pH]. The assertion "CO2 will change the pH of seawater" is completely bald thus an unscientific POV. I have looked at your reference ocean acidification, what it contains are a lot of assertions without data or analysis, clearly POV and "research to prove a thesis" instead of "testing a hypothesis". Look here [[24]], nothing but "possible impacts", is this "scientific proof" in this context, Stephan? --Damorbel (talk) 16:43, 20 December 2008 (UTC)

“Mix carbon dioxide with water and the result is carbonic acid. After that first simple chemical reaction comes a slightly more complicated series of changes in seawater chemistry. The final outcome is a lowering of the ocean's pH [...] Since the beginning of the industrial era, the pH of surface waters has decreased slightly but significantly from 8.2 to 8.1, and it continues to decrease.” See here (NASA). --Harald Khan Ճ 20:05, 20 December 2008 (UTC)

I'm completely confused. All the references say that the ocean pH = 8.2 and that a decrease in pH will cause a decrease in the carbonate ion concentration. However, Carbonic acid says that the pH should be 5.6 with current CO2 concentrations and that increasing the amount of CO2 will slightly increase the carbonate ion concentration. What am I missing? Q Science (talk) 05:55, 21 December 2008 (UTC)

See Le Chatelier's principle for the mechanism driving the process by which Carbonate compensation depth is determined. If the ocean were pure water, atmospheric CO2 would dissolve in it and drop the pH to 5.6 as you say. However limestone cliffs are steadily dissolving into the ocean, and are deposited at the ocean bottom. This steady flow shifts the equilibrium of the equations governing the dissolving of CO2 in the ocean, resulting in a much more basic liquid than if you just start with pure water and add carbon dioxide. --Vaughan Pratt (talk) 20:36, 24 November 2009 (UTC)

According to [[25]] page on ice cores, atmospheric CO2 always follows (yes it lags not precedes temp). The rise of the modern industrial age coincides with the end of the last Little Ice Age so how much of the 35% increase is due to the natural increase that would have happened without humans anyway? Secondly, according to the [[26]] page, the solubility of CO2 in sea water drops with the increase in said waters temperature.--Multiperspective (talk) 20:03, 5 December 2010 (UTC)

Two thoughts

How about some simple models - like the isothermal model - i guess kindof links in with the atmospheric pressure page???? is the air car link really worth having on this page? -deosnt really seem to link seriously with the subject. Wideofthemark

errors on page

This paragraph has errors: During the next few million years, water vapor condensed to form rain and oceans, which began to dissolve carbon dioxide. Approximately 50% of the carbon dioxide would be absorbed into the oceans. One of the earliest types of bacteria were the cyanobacteria. Fossil evidence indicates that these bacteria existed approximately 3.3 billion years ago and were the first oxygen-producing evolving phototropic organisms. They were responsible for the initial conversion of the earth's atmosphere from an anoxic state to an oxic state (that is, from a state without oxygen to a state with oxygen). Being the first to carry out oxygenic photosynthesis, they were able to convert carbon dioxide into oxygen, playing a major role in oxygenating the atmosphere.

1) First, there is no definitive evidence nor consensus that photosynthizing cyannobacteria were present on earth at 3.3 bya, though some scientists argue this. 2.6 ba or earlier is the scientifically safe statement -- see recent paper in nature, and tis references:

[[27]]

2) The paragraph fails to convey what we do and do not know about precambrian oxygen levels. See the same reference above as well as Goldblatt [[28]] This is not my field, and I'm working on another project of interest to me. Is there an earth scientist/ paleoecologist to look into this? I can supply a list of other pertinent references. Loco 00:01, 18 October 2006 (UTC)

3) I don't think mobile sources are the biggest pollutent, under climate change —Preceding unsigned comment added by 71.104.233.30 (talk) 06:14, 30 October 2009 (UTC)

Simple question.Why humans can see sky in a blue color. —Preceding unsigned comment added by 81.132.165.246 (talk • contribs) 18:44, 20 December 2006

The sky appears blue because of a physical effect called Rayleigh scattering. Have a nice day! 24.5.174.212 (talk) 11:52, 21 October 2008 (UTC)

Observational Database?

A large observational database of many different atmospheric constituents from a host of platforms including UARS is available. This was created as part of ESA Envisat and NASA Aura validation. It is of general use. Do you think it should be added to the article text?

Evoluton on Earth Section, Oxygen production error

The Evoluton on Earth Section states that Cyanobacteria "... were able to convert carbon dioxide into oxygen[,]" and "Photosynthesising plants would later evolve and convert more carbon dioxide into oxygen." This is an incorrect representation of photosynthesis. Oxygenic Photosynthetic life captures carbon dioxide in organic molecules used for energy storage and tissue construction in a process independent of the light reactions which splits water into gaseous oxygen and hydrogen ions. I've adjusted the passage to correctly reflect this, stating now that "[Cyanobacteria] were able to convert water into oxygen while sequestering carbon dioxide in organic molecules[,]" and "Photosynthesising plants would later evolve and continue releasing oxygen and sequestering carbon dioxide[.]" user:Anonymous 20 June 2007

vadalism

Hi,

I found someone vandalised this page

"This heating makes air masses less dense so they rise. When an air mass rises, the pressure upon it decreases so it expands, doing work against the opposing penis of the surrounding air"

How much breathable air is on Earth?

I have a question that seems like it would be relevant to this article. How much breathable air is on Earth at any one given time?

I see that the majority of the mass of the atmosphere is below the height of Mt. Everest. I know that most humans can breath naturally up to a height a bit lower than that, but my math is not up to calculating the volume of a spheroid and subtracting the volume the Earth. Obviously there would be some variables, and evaporation, etc. would make it change every so often. But is there a rough estimate of this number out there somewhere?

I would make rough estimate like this:

The real formula is v=4/3 pi a² b, (where π is the mathematical constant pi, and a and b are the equatorial and polar radii) and the volume of the Earth is "1,083,207,317,374 km3, or about 1.08321×10¹² km³, in scientific notation.[1] " But I don't have a good way to use that figure.

So if instead I turn that volume into a regular sphere, it would have a radius of 6371 km, or a diameter of 12742 km (1.08321 x10 ¹² = 4/3 pi r ³, solved for r). Earth's actual diameter varies from 12713 km to 12752 km. So that seems like a pretty good estimate. (It looks like 6371 is actually an official number used to estimate Earth's radius, so maybe that's how they came up with the 1.08321 number). This all seems to have something to do with the Geoid, but to be honest, I don't know enough geography about this concept, and it is difficult to correlate the Geoid with geological heights from "sea level."

So here where I get really rough. I know that the summit of Chimborazo is 6,384.4 km (3,968 mi) from the Earth's center. . I also understand Chimborazo is 6,267 meters above sea level. So, it appears "sea level" is about at 6378.2 km from the center of the earth? On the other hand, my arbitrary "max breathability" elevation is Everest Base Camp @ 5600 m above sea level, or 6,383.8 km from the center of the earth. They probably picked Chimborazo because it's near the equator and so further from the center of the earth than other summits, so I'll just round that number down to 6383. Then I calculate the volume of that larger "breathable" sphere as 1.08934 E+12.

By the way, I have no idea how the differences in gravitation affect the breathability of air above the pole vs. above the equator, but someone out there must know. It would be interesting to compare a calculation of the volume of air using that data and the v=4/3 pi a² b formula, or even more sophisticated methods, vs. this attempt.

So the difference between the two spheres is 6,129,226,437 km³. Does anyone have a real number to correct my back of the napkin figure? —Preceding unsigned comment added by Joevans3 (talk • contribs) 16:54, 27 July 2009 (UTC)

It depends on what you mean by "breathable air." One meaning would be the volume of the atmosphere when all of it is compressed to STP, which I calculated just now in the section immediately below as 3.9805×10⁹ km³. Another meaning, which may be the one you have in mind, is the volume of air at a sufficient pressure to be breathable, without compressing it at all, which could well be in the neighborhood of twice the compressed value. That is, the first digit in 6,129,226,437 km³ looks quite reasonable, although I wouldn't bet my life on the 7 at the other end (must have been a large napkin). --Vaughan Pratt (talk) 03:19, 24 November 2009 (UTC)

Constant pressure height is wrong

The article says

Were atmospheric density to remain constant with height the atmosphere would terminate abruptly at 7.81 km (25,600 ft).

I think this should be 8.498 km. Using data from NASA

14.71 psi surface pressure

0.07597 lb/ft3 surface density

(14.17 lb/in2 * 144 in2/ft2) / 0.07597 lb/ft3 = 27,882.59 ft -> 8,498 m

Q Science (talk) 22:52, 21 September 2009 (UTC)

I can't deal with those weird units, but let's double check:

density = (101325 Pa) / ((287.1 J kg-1 K-1) * 288 K)) = 1.225 kg m-3

scale height = (101325 Pa) / ((1.225 kg m-3) (9.8 m s-1)) = 8440 m

The expression can be algebraically simplified to Z = Rd T / g = (287.1 J kg-1 K-1) (288 K) / (9.8 m s-2) = 8437 m which works out within rounding error of the previous value and is close enough to what you get. Short Brigade Harvester Boris (talk) 23:55, 21 September 2009 (UTC)

The difference appears to be the density. According to this NASA reference

Surface density is 1.217 kg/m3 at 288 K (15 C), which gives a scale height of 8495.7 m (using your equation)

One of the failings of wikipedia articles (in general) is any discussion of how values like this vary depending on the source. In this case, I will agree that NASA appears to have the wrong (perhaps an older) value.

A reverse calculation indicates that the original 7.81 km would be correct for a temperature of 266.6 K. I wish that whoever added the original value had added a bit more information on where it came from. In keeping with that, I suggest some sort of note. Q Science (talk) 07:44, 22 September 2009 (UTC)

Unfortunately all the math above assumes that surface pressure is a good indicator of the actual total volume of Earth's atmosphere at STP, which it isn't because the Earth is far from being a perfect sphere, or even perfect oblate spheroid, at an 8 km scale (already Mt. Everest at 8.84 km has its top kilometer in a vacuum in this constant-pressure scenario).

A more accurate way of computing the volume at STP is by dividing the weight of the atmosphere, 5.148×10¹⁸ kg, by the weight .02897/.02240 = 1.2933 kg of a cubic meter of air (.02897 is a commonly-quoted weight in kg of a mole of air while .02240 is the number of cubic meters in a mole of any gas at STP). So, 5.148/1.2933 = 3.9805, making the volume of the total atmosphere 3.9805×10¹⁸ m³. Divide this by the surface of the earth, 5.10×10¹⁴ m², and one obtains 7,805 m, which rounds up to 7.81 km.

But is the difference between 7.81 km and 8.44 km a big deal for a hypothetical number that serves only to convey a sense of how much air there is? That the atmosphere extends beyond 100 km doesn't give as good a feel for how much air there is as saying that it would only reach to 8 km if the pressure didn't decrease. Given that the remaining digits depend on how you define the concept, how meaningful is a value with more precision than a simple 8 km? --Vaughan Pratt (talk) 01:15, 24 November 2009 (UTC)

It occurs to me that an argument that can be made for the 8.44 km figure is that it is exactly what the scale height of the atmosphere would be under the assumption of zero lapse rate. This is an easily seen consequence of the integral of e^x being itself. The reason the actual scale height is less than 8.44 km is because the temperature lapses going up, resulting in a denser atmosphere higher up than with no lapse. --Vaughan Pratt (talk) 19:18, 9 January 2010 (UTC)

Zero lapse rate is what "constant temperature" means. And it is true that using 0 C will give a different value than 15 C. In Scale height, it specifically says that the surface temperature should be used. Thus, 15 C is more correct than STP (0 C). Starting with the "total mass" is a bad idea because that value is most likely computed from the values you want to compute. Q Science (talk) 02:30, 10 January 2010 (UTC)

While I'm sure we're in agreement on every point here, let me just make a more precise statement to be sure. No matter what temperature one takes as "standard," "surface," or anything else, the scale height for a constant-temperature atmosphere will be identical to the result of calculating the constant-density height at that same temperature, assuming no lateral motion of air when adjusting its density to be constant.

Yes, I agree, except that the choice of temperature appears to be part of the definition of "scale height". Q Science (talk) 08:40, 10 January 2010 (UTC)

Another way of saying this, still assuming constant temperature T for any T, is that if you trap a one-square-meter vertical column of air, put a cap on it so high as to capture essentially all the air in the column, switch off gravity, and push the cap down isothermally (not adiabatically) until the pressure throughout the column (which will now be uniform) equals the original surface pressure, the cap will turn out to be exactly at the scale height at that temperature. --Vaughan Pratt (talk) 03:45, 10 January 2010 (UTC)

Also true, but with the same caveat as above. Q Science (talk) 08:40, 10 January 2010 (UTC)

Atmospheric Chemistry and Physics by Seinfeld and Pandis uses 253K to compute a scale height of 7.4km where 253K is the average of the surface temperature (288K) and the tropopause temperature (217K). I think this qualifies as an alternate definition of the scale height. Q Science (talk) 22:52, 11 January 2010 (UTC)

Atmospheric Color

The atmospheric color listed in the article is blue. While the explanation of why this is is correct (shorter wavelengths of light scatter more), this is not, in fact, true. The sky is actually purple (or ultraviolet, but generally the color of an object is understood to be limited to the visible ranges of light). Violet light has a shorter wavelength than blue light and so scatters yet more. The sky only appears blue because the human eye is tuned to see blue more easily than purple. See:

[29] [30] [31]

137.150.198.219 (talk) 21:19, 3 December 2009 (UTC)The Smiling Bandit

In one sense you are right, the amount of scattering is inversely proportional to wavelength but when the term color is used it is a matter of what the eye sees, you will find further explanation here Photometry (optics). --Damorbel (talk) 06:46, 4 December 2009 (UTC)

(I used to teach this stuff long ago at Stanford in CS248A,B (Computer Graphics) before we hired Marc Levoy and Pat Hanrahan.) Here's the scoop. Violet is a color one can see (look at a spectrum). The sky is obviously not the color one can see at the violet end of the spectrum, it is much more blue than that as anyone can tell just by looking, and moreover not a saturated blue but more of a pastel blue.

While there's some truth to "the human eye can see blue more easily than violet," that can't be all there is to it or if you turned down the intensity of blue light it would look more violet, which it doesn't, yet there is nonetheless a color we recognize as violet (and it isn't purple or magenta, which are colors that have red in them). The human eye can only distinguish between colors that live in a three-dimensional subspace of the infinite (or at least very high) dimensional space of all physical colors, i.e. all spectra in the visible range. This is because the eye has only three kinds of cones sensitive to long, medium, and short wavelengths, abbreviated L, M, S. Here are the criteria by which the eye makes its primary distinctions.

The eye's response even to coherent (single-wavelength) light is quite subtle. The conventional monochromatic colors from short to long are violet, indigo, blue, green, yellow, orange, and red. Violet is the wavelength that registers only with the S cones, the M and L cones do not respond to violet. Indigo has a strong S response and weak M and L; it has a reddish tinge to it because L is relatively strong compared to M just there. As one moves to Blue S remains relatively strong, M starts climbing, but L does not climb as fast as M and the reddish tinge of indigo therefore disappears, not to return until much later when M peaks and L starts to overtake it. Moving towards the tricky blue-green transition, S starts declining while M climbs just as fast but with L also climbing and not that far behind M, with that transition being where S and M are balanced. Green is where S is mostly gone, M is peaking, and L is getting near its peak. Yellow is when S is gone, M is fading, and L is peaking. Orange still has some M but much weaker than L. Red is when S and M are essentially gone and L is fading, with the deepest red corresponding to L weakening until the end of the visible spectrum is reached.

The blue of the sky is none of these but rather a pastel color resulting from a spectrum that shades off smoothly from the violet end all the way down to the deep red end--a little red is necessary for the pastel effect. This smooth rolloff is a different physical spectrum from what is obtained by taking pure white (all three colors) and mixing in some purely monochromatic blue, but to the unaided eye these two quite distinct physical spectra are completely indistinguishable. ("Unaided" is important because one can distinguish them with filters, a trick used in WW2 by the French to spot camouflaged German tanks whose camouflage used a spectrum very unlike what it was trying to blend in with.) Therefore to the eye the sky is a medium pastel blue. --Vaughan Pratt (talk) 05:07, 10 January 2010 (UTC)

The part about the low altitude pastel blue needing some red, is true-- if you go to high altitudes, an act which removes more red than blue, the sky really does turn far more purple. This is NOT just due to lack of light and the black of space showing through, for then it would look similar to the low altitude sky at twilight (same light intensity) and it doesn't. The high altitude sky, even adjusted for the same light intensity as below, is quite a different color. SBHarris 06:00, 10 January 2010 (UTC)

Viewing the sky from a high altitude decreases the path length of sunlight through the atmosphere, whereas viewing it from the ground with the sun low increases the length. The latter further scatters the light, compensating to some extent for the reduction in total light from the Sun and therefore not producing anything like the darkening effect of decreasing the path length. There is therefore no reason to expect any similarity between the two. --Vaughan Pratt (talk) 11:46, 16 January 2010 (UTC)

The Rayleigh scattering is not the only effect giving the sky its colour, water droplets scatter quite strongly even when not visible as clouds, they are too big to have a wavelength effect but scatter white light and thus spoil visibility, it is why hills fade with distance (perhaps I'm wrong about the colour of water scattering, what is it that gives distant hills that purple tint, perhaps both effects are at work.)--Damorbel (talk) 10:34, 10 January 2010 (UTC)

Water vapor consisting of H2O in gas form averages 1% of the atmosphere and as such contributes negligibly to total Rayleigh scattering by oxygen and nitrogen. Scattering is more pronounced when the water vapor condenses to water droplets, which along with a wide range of aerosols is covered under Mie theory and visibility. --Vaughan Pratt (talk) 11:46, 16 January 2010 (UTC)

Solar-cycle-driven expansion and contraction

I recently learned that the expansion and contraction of the atmosphere very substantially affects the background rate of the "natural" re-entry of human-made space debris; to wit: "Manmade space debris have been dropping out of orbit at an average rate of about one object per day for the past 50 years.<code><ref name=ss20111205b/></code> Substantial variation in the average rate occurs as a result of the 11-year solar activity cycle, averaging closer to three objects per day at solar max due to the heating, and resultant expansion, of the Earth's atmosphere. At solar min, five and one-half years later, the rate averages about one every three days.<code><ref name=ss20111205b> {{cite web |last=Johnson|first=Nicholas |title=Space debris issues |date=2011-12-05 |url=http://www.thespaceshow.com/detail.asp?q=1666 |work=audio file, @0:05:50-0:07:40 |publisher=The Space Show |accessdate=2011-12-08 }}</ref></code> (Nicholas Johnson is NASA's top expert on space debris.)

In the Atmosphere of Earth article, I don't see that we say much about this, either in terms of density changes at various nominal altitudes, or in where the atmospheric drag effect on orbiting objects is greatly affected (re-entry in days/weeks, rather than months/years). The article currently says (only?) this:

The top of the thermosphere is the bottom of the exosphere, called the exobase. Its height varies with solar activity and ranges from about 350–800 km (220–500 mi; 1,100,000–2,600,000 ft).

Just my two cents: if anyone knows of any good sources for the technical description of the solar cycle effect on Earth's atmosphere, I think the article would be much improved by its addition. Cheers. N2e (talk) 22:05, 8 December 2011 (UTC)

The quote above is from Space_debris#Dealing_with_debris. Q Science (talk) 06:54, 23 December 2011 (UTC)

pressure/altitude graph

http://en.wikipedia.org/wiki/File:Atmosphere_model.png

What are these dashed horizontal lines in semilogarithmic pattern for? It would be ok if values at solid lines were 10 times different, so that they correspont to 2e-6, 3e-6, etc but they are 1000 times different. —Preceding unsigned comment added by Linefeed (talk • contribs) 22:11, 28 December 2009 (UTC)

That is a pretty standard way to draw a semilog graph. The horizontal dashed lines are 1, 2, 3 ... for the associated decade. Q Science (talk) 01:32, 10 January 2010 (UTC)

But here is no 'associated' decade - solid lines differ by 1000-fold, not 10. After 1E-6 (solid line) are there supposed to be 2E-6, 3E-6, ... 9E-6 and right afer it 1E-3? Linefeed (talk) 19:12, 28 January 2010 (UTC)

You are absolutely correct, that graph makes no sense. Q Science (talk) 20:42, 24 September 2010 (UTC)

Each "decade" is cubed, namely 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000. The eight dotted lines are the cubes 8 to 729. (I noticed this a couple of years ago but didn't think of it as a problem at the time. Might be worth labeling the dotted lines; for the time being I've put it in the caption just now.) --Vaughan Pratt (talk) 20:14, 3 October 2010 (UTC)

Article probation

Please note that, by a decision of the Wikipedia community, this article and others relating to climate change (broadly construed) has been placed under article probation. Editors making disruptive edits may be blocked temporarily from editing the encyclopedia, or subject to other administrative remedies, according to standards that may be higher than elsewhere on Wikipedia. Please see Wikipedia:General sanctions/Climate change probation for full information and to review the decision. -- ChrisO (talk) 15:58, 2 January 2010 (UTC)

Structure of the Atmosphere: Diagram vs. Explanation

Under the "Structure of the Atmosphere" heading, there is both a diagram illustrating the layers of the atmosphere and a textual explanation of each layer. However, while the diagram is shown in a highest to lowest altitude, the textual explanation is shown in a lowest to highest altitude, creating potential confusion. Should this be resolved? Titus.jon (talk) 02:45, 13 January 2010 (UTC)

I agree. And it used to be that way. However, someone changed it because he could. I argued against the change, but there was no support. Q Science (talk) 08:41, 13 January 2010 (UTC)

Preserving good-faith edits

The following good faith edits were removed (rightly I think), but with some more work parts of it could be added to the article. This section is to preserve the "raw material". Martijn Meijering (talk) 14:56, 23 April 2010 (UTC)

Since the formation of the Earth 4.5 billion years ago, our planet has undergone vast changes. The early Earth was bombarded continuously by meteorites, which heated and melted much of the planet. As the solar system aged, meteorites impacted our planet less frequently. With the outgassing of volcanoes and the development of our atmosphere, we are now protected from many of the smaller celestial objects that may cross our orbit.

Radioactive materials present at the time of Earth’s formation have continued to decay producing large amounts of internal heat. We see the effects of these two forces and their energies in the volcanic activity present on Earth today. Earth also receives energy from a nuclear reaction as well. Our Sun is a large sphere of gas and its largest component is hydrogen gas.

The hydrogen molecules are under intense gravitational forces, which, combined with frictional forces, are enough to cause individual hydrogen molecules to undergo a nuclear fusion reaction creating molecules of helium and liberating vast amounts of energy.

This energy is given off as electromagnetic waves; some of this radiation is in our visible range. The light from the sun travels through space and is absorbed by the Earth. Most of the radiation from the Sun passes right through the thin atmosphere or is reflected back into space.

The Earth absorbs the light energy or radiant energy and heats up. It then re-radiates the heat out and up into the atmosphere as heat energy or infrared radiation. The Sun’s energy is necessary for almost all life on Earth. This is especially true for humans.

(i got all info from my earth science class. this section is seperate from the wiki page)

Space/atmosphere boundary

The second paragraph down from the start of this article includes the sentence, "The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space."

I view this as being inaccurate since a recent discovery was made showing definitively the boundary between the atmosphere and space. Should this article be revised to reflect this new data?

Further details can be found in the www.space.com news article, "Edge of Space Found." This is the link: http://www.space.com/scienceastronomy/090409-edge-space.html —Preceding unsigned comment added by 67.170.91.242 (talk) 17:25, 11 July 2010 (UTC)

That page you link to is highly inconclusive at best. It states even within itself that there are many ways to judge the boundary between space and atmosphere. And then goes on to say that using one method only, charged particle flow, that they can say that is somehow the way to judge the definitive boundary. But they give no justification as to why that method should be the "proper", or definitive, method. HumphreyW (talk) 23:52, 11 July 2010 (UTC)

nitrogen

i think i commented on this earlier, but 78.09% nitrogen seems ... kind of high? i'm going to go ahead and change this to oxygen. i assume that is what it is supposed to be, and hopefully no-one will complain. -sio. (talk) 18:00, 9 August 2010 (UTC)

The atmosphere is 78% nitrogen, 21% oxygen, 1% others. What's the issue? – iridescent 18:02, 9 August 2010 (UTC)

Looking over Sio6627's edits (including a long stretch where I argued with him at TALK:solar core, I believe he is not actually stupid. Rather, he is a classic troll. Could somebody please blockify him for a while? SBHarris 19:45, 9 August 2010 (UTC)

Trust me, I'm watching him. He's had his final warning; he seems to have got bored and gone away. – iridescent 19:51, 9 August 2010 (UTC)

Proposed merge from Atmospheric_stratification

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was to merge Ovis23 (talk) 17:57, 14 January 2011 (UTC)

---

Currently, the article Atmospheric_stratification and the Earth's_atmosphere#Principal_layers section in this article coexist. They are redundant. I suggest one of two options:

1. Merge Atmospheric_stratification into Earth's_atmosphere#Principal_layers. Advantages to this suggestion include removal of redundant information, and compilation of information into the more established and better-organized article. This would likely length the section on this page slightly.

2. Move detailed information from Earth's_atmosphere#Principal_layers to Atmospheric_stratification, and provide a link between the two.

Thoughts? I have tentatively proposed the first option with mergefrom and mergeto headings.

Ovis23 (talk) 05:18, 5 November 2010 (UTC)

A merge seems like a good idea to me, in this case (so option 1). Mlm42 (talk) 22:42, 9 December 2010 (UTC)

Merge! Logically Atmospheric_stratification should be part of Earth's_atmosphere#Principal_layers--Alvez3 (talk) 01:55, 29 December 2010 (UTC)

Merging makes sense to me. Thegreatdr (talk) 02:04, 29 December 2010 (UTC)

Okay then, will do. Ovis23 (talk) 17:57, 14 January 2011 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Defining features of the layers

I like that there is a section on the layers of the atmosphere, but the blurbs about each layer seem to fail at explaining what their defining characteristic is.. how are the layers defined? Presumably they are not defined to be a certain height range, but instead there are some other defining features which may cause their heights to vary.. so what exactly are these defining features? Some of them seem related to temperature, but the definitions could be made more explicit. "The thermosphere is the region of the atmosphere such that ..." along those lines.. at the moment, the blurbs emphasize where the layers are, without explaining fully what the layers are.

Also, are the definitions of the layers widely excepted, or do different sources define the layers in different ways? These are question I'd like to see addressed, if possible.. thanks! :) Mlm42 (talk) 19:11, 14 January 2011 (UTC)

The change in temperature with altitude defines the layers, except that there are at least two different definitions for the tropopause - one describes it as being about 10km thick[32] and the other assumes that it has zero thickness (IPCC usage). As a result, some papers discuss the tropopause and others discuss the lower stratosphere, but they are both discussing the same layer of the atmosphere. Q Science (talk) 21:14, 19 January 2011 (UTC)

Something important about the Atmosphere isn't found here —Preceding unsigned comment added by 209.183.23.213 (talk) 19:18, 30 January 2011 (UTC)

Earth´s atmosphere and scintillation

Could anyone specify (perhaps in section "Refractive index", where scintillation is mentioned) which are the main layer or layers contributing to astronomical scintillation (and perhaps terrestrial also, if it applies)? Many thanks. Pmronchi (talk) 03:48, 19 January 2011 (UTC)

Steady State?

The article describes the current atmospheric oxygen level of 15% as a "steady state." But the accompanying graph would suggest that it is has only been steady for a very short time frame, geologically speaking. Can we clarify this or change the wording? —Preceding unsigned comment added by 68.142.40.131 (talk) 02:35, 1 March 2011 (UTC)

Rounding error...

I notice that, according to the lede of this article, nitrogen, oxygen, argon and carbon dioxide between them make up almost 100.01% of the atmosphere. I realise that it's likely a rounding error, but is there some way of making that part of the text seem a bit more sensible? Grutness...wha? 04:57, 1 March 2011 (UTC)

euh. I just noticed that a very similar point was brought up over a year ago, further up this page. Grutness...wha? 04:59, 1 March 2011 (UTC)

Merge with Earth's atmosphere (Meteorology)

The Earth's atmosphere (Meteorology) article is an orphan and its scope substantially duplicates the Atmosphere of Earth article. The redundancy of the former article has been asserted on that article's talk page for the past five years, but no one has formally proposed the merge. As such, I recommend that Earth's atmosphere (Meteorology) be merged here. Neelix (talk) 21:05, 11 March 2011 (UTC)

In my opinion, merging its content into the troposphere article would be a better fit, since weather is primarily a tropospheric issue. Thegreatdr (talk) 21:42, 11 March 2011 (UTC)

Unreferenced material

There is loads of unreferenced material. This really needs to be edited by an expert who will have references to the material that is stated, but not substantiated. Drkirkby (talk) 06:25, 11 May 2011 (UTC)

The percentages of gases in the atmosphere sums up to more than 100%... —Preceding unsigned comment added by 78.91.4.50 (talk) 09:28, 13 May 2011 (UTC)

doubt

'Atmosphere of earth' means that we have an atmosphere made of earth. Should it not be 'Atmosphere of the earth'? — Preceding unsigned comment added by 109.145.195.102 (talk) 09:56, 5 June 2011 (UTC)

Serious readers are unlikely to interpret the title as "atmosphere made of earth." In some very few contexts, it could be taken to mean that, but really... In pedantic terms, this article's title uses the word "Earth" as a capitalized proper noun, referring obviously to the planet Earth. __ Just plain Bill (talk) 12:46, 5 June 2011 (UTC)

Few readers will misunderstand the context of meaning belonging to or derived from. "Atmosphere of earth", in your misunderstanding would be an abbreviated form of atmosphere made of earth, a topic limited to victims of mining accidents and avalanches. —EncMstr (talk) 16:37, 5 June 2011 (UTC)

Although few readers will interpret it as "atmosphere made of earth" it seems that it should be changed simply because it is more correct to say "Atmosphere of the Earth."--174.34.41.239 (talk) 03:32, 12 June 2011 (UTC)J28

The name of the planet is Earth, not the Earth. We never refer to the Venus or the Mars. HiLo48 (talk) 03:45, 12 June 2011 (UTC)