Latest comment: 1 January 20161 comment1 person in discussion
The very first sentence says "The troposphere is the best portion of Earth's atmosphere". I was wondering if the adjective "best" is not a somewhat unusual choice in this description? Thanks. Todd (talk) 20:41, 1 January 2016 (UTC)Reply
Equation
Latest comment: 22 January 20081 comment1 person in discussion
I have added a correct explanation of the reason for the decrease of temperature with height to the main article. Let me know if it's still not clear. 209.131.85.20120:00, 3 August 2007 (UTC)Reply
Well, guessing from the name, I would say it has something to do with atmospheric pressure. The pressure is lower at high altitudes, and according to the ideal gas law, as pressure goes down, temperature decreases as well. Meelar(talk) 18:16, August 16, 2005 (UTC)
The red link should have pointed to Joule-Thomson effect (it does now). However, I don't think this is correct (the thermodynamics in that section of Earth's atmosphere look decidedly iffy to me), so I will try to do a quick explanation here. The troposphere is not heated directly by the sun: any radiation from the sun which can be absorbed by the atmosphere has already been filtered out in the thermosphere and (especially) the stratosphere. The troposphere is heated directly by the Earth's surface. The heating effect decreases as you move away from the Earth's surface, and so the temperature decreases. Anyone else want to fill out the vast simplifications I've made there? Physchim6200:48, 17 August 2005 (UTC)Reply
The ideal gas law is not necessarily valid for the troposphere. If the air is moist, then when it cools, water can condense out of it: this situation is not covered by the ideal gas law. As for the heating of the surface, what you describe is heat being transported from the Earth's surface to the atmosphere by conduction, but convection is much more important as a source of heat transport in the troposphere. So that's not the right answer either. 209.131.85.20120:00, 3 August 2007 (UTC)Reply
Not really, except to show that there is no relation between pressure (roughly proportional to mass density, especially given the log scale) and temperature for the Earth's atmosphere. Enlighten us, please, Happy Camper, I've known you more inspired ;P Physchim6201:59, 17 August 2005 (UTC)Reply
Nice plot: you can really see the different layers in the temperature. I remember a particularly painful exam which included basically this question, but all it taught me is that you shouldn't expect people to learn anything new (like say whether expansive cooling alone can explain the observed temperature drop) in a high time pressure environment. --Laura Scudder | Talk07:26, 17 August 2005 (UTC)Reply
I don't really know much about the atmosphere, but I think one major contributor to the temperature inversion in the second layer (the stratosphere) is the presence of ozone at the bottom of it. Ozone is highest in concentration in this area. Its absorption of ultraviolet light is essentially dissipated as heat which I think rises away from the earth instead of sinking down to the earth. What I don't understand is how this causes the temperature to go up so significantly. Ozone must be dissipating a tremendous amount of energy! I'm not sure what happens at the top. I guess the temperature that is being plotted is the "kinetic temperature". The density of matter at that region is so low that this particular notion of temperature probably would be less meaningful. I guess what's really important to recognize is that the atmosphere is not at all homogeneous. I might also add that commercial airlines' flight routes will fly in the stratosphere because the air mass there is quite stable. --HappyCamper10:23, 17 August 2005 (UTC)Reply
You're right about the contribution of ozone to stratospheric warming, although I would guess that oxygen and nitrogen play their part as well, at their particular absorption frequencies. What is clear is that N2 and O2 are not heated in the troposphere, as there is no longer any radiation of the correct wavelength. Yes, the ozone layer absorbs (and hence eventually dissipates) a tremendous amount of energy! Half of it is re-emitted towards the Earth's surface (the greenhouse effect), half of it into space. And yes, I assume they are defining temperature in the upper atmosphere with regards to the speed distribution of the few gas molecules which are there. Physchim6202:00, 18 August 2005 (UTC)Reply
I hope the revised article now explains this properly. The cooling with increasing altitude is due to adiabatic expansion. Let me know if this is still not clear.--NHSavage10:06, 18 March 2006 (UTC)Reply
The scales of the atmospheric cross-section are way off. Although the caption makes a brief note of this, the figure really should be replaced with a better one with a) a linear or logarithmic vertical scale; and b) a line indicating the Earth's surface (rather than the globe of the Earth, which to some readers will suggest that the Earth's atmosphere is far thicker than it truly is).
Revisions to Pressure and Temperature section
Latest comment: 5 July 20082 comments2 people in discussion
I forgot to leave an "edit summary" for the changes that I made this afternoon. I added a lot of references, added a correct explanation of the decrease of temperature with height, and deleted some incorrect material. (For instance, the incorrect argument was given that rising air has to do work against gravity, which causes it to lose energy, and thus the temperature decreases. This is incorrect, because the work done by gravity is exactly balanced by work done by the buoyant force, if the atmosphere is in hydrostatic equilibrium -- the condition expressed by the displayed equation in the pressure section.)
There are still a lot of missing references and unsupported facts in the article.
The formulae for pressure and temperature appear to use a constant for density (ρ), at first sight this is misleading if not erroneous since density is a fn of height. This should be made clear --Damorbel (talk) 08:30, 5 July 2008 (UTC)Reply
WikiProject class rating
Latest comment: 9 May 20102 comments2 people in discussion
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot10:05, 10 November 2007 (UTC)Reply
"As the air parcel expands, it pushes on the air around it, doing work; but generally it does not gain heat in exchange from its environment, because its thermal conductivity is low (such a process is called adiabatic). Since the parcel does work and gains no heat, it loses energy, and so its temperature decreases."
Latest comment: 24 January 20162 comments2 people in discussion
This article is about the troposphere, not the atmosphere. The graphs do not have sufficient resolution to display any meaningful information about the troposphere. Can we get some pictures that show properties such as temperature and compostion of the atmosphere from sea-level to say 20km altitude; and not to outerspace! So, I'm deleting the pictures, and starting over, I'll keep my eye open for something to upload or make one myself. THanks.--Charlesrkiss (talk) 16:01, 21 March 2009 (UTC)Reply
I'm pasting this image (that I cut from the article) and its caption here, since it seems on topic for this heading. The text in the image is illegible, and it adds no information about the subject.
File:EarthAtmosphereBig.jpgEarth atmosphere diagram showing the exosphere and other layers. The layers are to scale. From Earth's surface to the top of the stratosphere (50km) is just under 1% of Earth's radius.
Latest comment: 17 April 20144 comments4 people in discussion
This article writes in Atmosperic Levels section:
1) Low Level is from zero to 2400m altitude
2) Mid Level is 1800 to 7600m altitude
3) Upper Level is the highest of the three level and starts from 850hpa and above.
The 3rd is a wrong statement compared with the first two because 850hpa surface lies approximately at about 1500 meters altitude, thus upper level starts below mid level which starts from 1800m altitude and ends to 7600m altitude. Upper level cannot be "the highest level" if starts below mid level.
National Weather Service Glossary defines "upper level" as "the portion of the atmosphere that is above the lower troposphere, generally 850 hPa and above."
In the same Glossary is mentioned that "local cooling of the air in middle levels of the atmosphere (roughly 8 to 25 thousand feet), which can lead to destabilization of the entire atmosphere if all other factors are equal" not as a definition of a "mid level" but inside the definition of "mid level cooling". Obviously these two definitions of middle and upper atmosphere levels are not agree each other.
Finally this Glessary does not define "Low Level" or "Lower Level" at all.
I think that National Weather Service Glossary is not an accurate Glossary and needs more work to define better the terms.
Also the level of troposphere must be written in a better way in Wikipedia.
--91.140.98.49 (talk) 23:34, 5 June 2011 (UTC)--91.140.98.49 (talk) 09:44, 6 June 2011 (UTC)Reply
I generally agree with the comment above. The levels section is basically apples and oranges, and the sources used for Lower, Mid and Upper are talking about different things, and you can't suggest they're stacked this way in the troposphere. The Low and Mid level heights as listed generally correspond to the heights used for clouds, and High (not upper) clouds would be found above 7km or so (depending on latitude...) The term Upper Air usually refers to conditions away from the surface, above ca. 1500m, whereas the upper atmosphere is above about 85 km. The section is useless at best and misleading at worst. — Preceding unsigned comment added by 204.77.41.253 (talk) 19:35, 7 September 2011 (UTC)Reply
The section on composition doesn't actually state the elemental composition, or contain the words 'oxygen' or 'nitrogen'. That to me seems like a serious deficiency. — Preceding unsigned comment added by 206.45.162.228 (talk) 21:17, 7 December 2013 (UTC)Reply
Latest comment: 23 May 20151 comment1 person in discussion
The article says that 75% of the mass of the atmosphere is in the tropsphere. The reference for this is quoted as saying that 4 5ths of the atmosphere are in the troposphere. That's 80%, not 75%... Is there a reason to directly contradict the reference cited? — Preceding unsigned comment added by 92.228.176.27 (talk) 13:38, 23 May 2015 (UTC)
This is not good. Wikipedia can't get the proportion wrong. We need to fix this. — Preceding unsigned comment added by Tempaccount-424895-4328 (talk • contribs) 01:21, 22 September 2015 (UTC)Reply
Composition - only lacking composition
Latest comment: 28 November 20233 comments2 people in discussion
Now what use of a "Composition" section, if one can't learn from it the composition of the troposphere?
I'd suggest adding a sentence to this section that would actually contain the information regarding the troposphere's composition (nitrogen-78%, oxigen-20%, carbon-dioxide-1%, other trace elements, etc).
176.63.176.112 (talk) 17:35, 28 December 2016 (UTC).Reply
Latest comment: 3 December 20171 comment1 person in discussion
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Latest comment: 15 August 20181 comment1 person in discussion
The lead states that "The average height of the troposphere are...". Well, us English speakers (readers) know that "the X are" is only correct if X is plural; "height" is not plural. But that is not why this is awful. The troposphere is - and apparently this will be news to the editors - a layer of atmosphere having substantial dimension (call it a height or depth). The "average height" depends on what you're averaging. If you're averaging distance between the Earth's solid/liquid surface and the tropopause (which has a depth itself) then it would be roughly HALF of its total height/depth. (The article on the tropopause claims it begins at about 17 km (on average) over the equitorial Earth, yet here the claim is the Troposphere averages 18 km there. This is an obvious contradiction. Anyway, we could also take the "average" by mass (or pressure/density) and would get (two other) different values. Either way, the average is NOT the average maximum. If you're going to use the term "average" please explain WHAT is being averaged. The statement that average height is X MUST imply that 50% of X is above X and 50% is below, which is not what is meant here. Sad.75.90.39.77 (talk) 19:13, 15 August 2018 (UTC)Reply
This page should be renamed Earth's Troposphere
Latest comment: 29 August 20191 comment1 person in discussion
1 & 2) The illustration with the layers shows one set of data, contradicted massively by the bulleted list in the caption, which is again contradicted by the caption's last paragraph (±50 km is very far from 50–60 km; ± can't possibly mean a >20% variation - from below 50 to 60). This is a record even for Wiki.
3) Besides, the bulleted list is fundamentally wrong, as it states next to each section that it is "at X km", while its actual intention seems to be to indicate the utmoust height of the respective section, so it should probably read "up to X km". But it's all unsourced, and guessing ain't knowing.
4) I'd always start from the bottom, not from above. It's not only logical, but even the names relate to the distance from the Earth's surface going up.
A cosmic-level mess.
"The atmosphere of the Earth is in five layers:
(i) the exosphere at 600+ km;
(ii) the thermosphere at 600 km;
(iii) the mesosphere at 95–120 km;
(iv) the stratosphere at 50–60 km; and
(v) the troposphere at 8–15 km.
The distance from the planetary surface to the edge of the stratosphere is ±50 km"