Talk:Tropopause

Lapse rate

Lapse rate is defined as the negative rate of change (of a variable) with respect to height. In the tropopause, the lapse rate is positive as temperature decreases as height increases. In the stratosphere the lapse rate is negative as the temperature increases with respect to height. —Preceding unsigned comment added by 60.240.120.95 (talk) 10:51, 31 August 2009 (UTC)

Mountains

Is there any mountain high enough to peak above a part of the troposphere thin enough to be peaked by the mountain at hand? This data could do great to the article, in addition, if more than one mountain could do so, could it do so with the stratosphere too? I doubt so since the Everest is like almost 9 km tall but even then, I dunno really... Herle King 07:35, 14 March 2007 (UTC)

Generally speaking, atmoshperic levels are raised by mountains, so the mountain wouldn't reach into the tropopause. However, Everest is above the height of the tropopause in some surrounding areas. Eebster the Great (talk) 02:13, 3 September 2008 (UTC)

From what I understand, the tropopause frequently dips below Everest at the summit. This information is relevant to climbers since when it happens, even those with the most freakish VO2's can't summit without oxygen. Peteymills (talk) 04:29, 11 February 2011 (UTC)

http://weather.uwyo.edu/upperair/sounding.html That site has several years of upper air data from around the world. Looking at the stations nearest Everest, the tropopause seems to be around 16-17km high in that region, which is nearly twice the height of Everest. It's at too low a latitude to reach it. The reports about the 1996 disaster referring to "the stratosphere falling in" actually mean the air pressure dropped to a level normally found at over 9000m; but the tropopause is defined by temperature and lapse rates, not pressure.

However looking at the data from Alaska stations, it appears that at times the tropopause in the Anchorage area can drop as low as 6000-6500m (though it is typically more like 8000-9000). Denali therefore might occasionally sit on or just above it. Walshie79 (talk) 14:28, 10 January 2019 (UTC)

The radiosondes from the database of the University of Wyoming do not include the tropopause. On what grounds you claim what you claim?--Jetstreamer ^Talk 16:52, 10 January 2019 (UTC)

The soundings include the temperature at various heights. From that you can deduce the lapse rate and whether the 2C/km thresholds are met. Walshie79 (talk) 10:10, 14 January 2019 (UTC)

What you propose is pure original research, the tropopause estimated that way is not even scientific and can lead to bulk errors. The WMO definition should be implemented trough an algorithm on each sounding to calculate the tropopause. If you apply the WMO definition, i.e. the 2ºC/km bit, the way you propose you will find that inversions in the lower troposphere also satisfy the criterion and can easily be interpreted as tropopauses when they are not. This is not as simple as it seems.--Jetstreamer ^Talk 13:03, 14 January 2019 (UTC)

Anvil Cloud

When you see a cloud (usually a thundercloud) form a sort of anvil shape at the top of the cloud, is this because it's hitting the stratosphere/tropopause? ~Hobo

Merge with with troposphere

I am currently reworking the troposphere article and I feel that this article would be better as a section of that one. I will merge the contents from here. The draft is at: User:NHSavage/sandbox. Comments please.--NHSavage 08:58, 25 February 2006 (UTC)

I have now changed my mind. It doesn't belong there and we can put a lot more in here.--NHSavage 10:00, 18 March 2006 (UTC)

I'm not sure describing that there are two "types" of tropopause's is correct. It might be better to describe the tropopause as being a disjointed boundary. It's height being a function of near surface temperature. Warm air "pushes" the tropopause to higher levels as the air expands and cold air drops the tropopause as the air is contracted (of course to understand this completely the tropopause needs to be explained as having atmosphereic stability). Therefore, with large surface temperature variations, there will be large height variations. In some cases as much as 20,000 ft height change in 500 nm (typically around polar front). There are three principle tropopause height changes, each associated with significant temperature changes from atmosphereic cells of the Hadley Cell, Ferrel cell and Polar cell. --Pugzi 08:34, 13 July 2006 (UTC)

the thickness

why does the thickness of the troposphere get thinner as the latitude increases? Maybe you can add the explanation to it User:Tikai 08:07, 21 April 2007 (UTC)

See the note above by Pugzi regarding the relation with surface temperatures and atmospheric cell boundaries. 92.0.230.198 (talk) 13:17, 24 July 2015 (UTC)

Suggested Edits

This section could use a rework, with all due respect, although I think the original author is eminently more qualified to do so than I. In terms of a focused encyclopedic entry on the tropopause, I think that a lot of the detail on the stratosphere and troposphere is supernumerary. Focus on the tropopause itself and leave detail about the broader troposphere/stratosphere to another article.

I'm also missing the explanation that led me to the page in first place -- I know I knew this back in SS3201:Physics of the Atmosphere, but I've forgotten over the intervening 20 years: why is the tropopause? I know dT<0 below and dT>0 above, but I can't remember why, its driving me nuts, and that is a broader element that would be relevant to the tropopause article. It's there because the temperature trend changes -- why does it change?

Off to the stratosphere article to try and remember...

... some time later ... Ah, yes, I thought that might be it. Still the reason for the cooling/warming switch is valid here.

208.118.34.80 (talk) 20:51, 30 August 2008 (UTC)dirkman

contradiction

the section on this pages that states the altitude ranges for the troposphere directly contradict what the "troposphere" page says.... whcih one is correct? —Preceding unsigned comment added by 134.84.11.45 (talk) 17:54, 29 June 2009 (UTC)

Aircraft fly above or below tropopause?

In this article, it is indicated that commercial aircraft generally fly below the tropopause. However, the exact opposite assertion is made in the Stratosphere article. 152.5.254.24 (talk) 21:07, 10 June 2010 (UTC)

Definition

The article says the exact definition of the tropopause is "the lowest level at which the lapse rate decreases to 2 °C/km or less, provided that the average lapse rate between this level and all higher levels within 2 km does not exceed 2 °C/km." How can this be an exact definition when it does not specify the range over which the lapse rate is to be averaged? A short range could produce a much higher tropopause than a long one. --Vaughan Pratt (talk) 22:27, 3 October 2010 (UTC)

The updated definition I've just added clarifies this point.--Jetstreamer (talk) 15:05, 27 October 2011 (UTC)

Cleanup

I added headings to divide the article section but what goes in each section needs to be reviewed.

Unsigned. Will remove the tag.--Jetstreamer (talk) 18:00, 26 October 2011 (UTC)

Nonsense

Hi Jetstreamer, why did you revert my corrections? Now the heights are wrong again, a citation is missing again, a wrong source is back, and the statements about lapse rates are wrong again. If you want kilometers instead of feet, just edit that, but don't do a complete revert. --Suaheli (talk) 06:07, 30 March 2012 (UTC)

Hello. The article is in the process of reorganisation. It's not that I want units expressed in kilometers. Even worse, the concept you introduced is wrong. The tropopause is not located where the gradient becomes zero, but it is defined where the gradient falls below a threshold. The WMO definition does state that, and it is included in a box at the beginning of the page.--Jetstreamer ^Talk 13:57, 30 March 2012 (UTC)

I agree, the gradient needs to fall below a threshold -- that's about the same as saying the lapse rate becomes zero. What I corrected are the following mistakes: 1. "At the tropopause the lapse rate changes from positive to negative" (I say: it first remains constant in the lower stratosphere before it becomes negative with increasing height). -- 2. "At the poles the tropopause is located at 36000 ft" (I say, at the poles it is rather 20000 ft, see my now deleted source, or take any other scientific source). -- 3. "Gettelman, A.; Salby, M. L.; Sassi, F. (2002)" (I say, this source mentions the tropopause height in tropical regions only, not at the poles where the height is much lower than 36000 ft). -- With your revert you didn't eliminate any error, you just re-introduced at least 3 errors. Are you really a meteorologist? --Suaheli (talk) 01:32, 31 March 2012 (UTC)

I have corrected the first of the issues you raised, as it was wrongly described. More specifically, the sentence The tropopause location coincides with the point at which the lapse rate reverses its sign was changed to The tropopause location coincides with the lowest point at which the lapse rate falls below a prescribed threshold. It is very unlikely for it to coincide with the level at which the temperature gradient is zero, and in most of the cases it falls below that point. Furthermore, I have added a reference for the height at the poles, and also corrected the number, which turned out to be 2 kilometers below the value stated in the article. I'm aware that Gettelman et al.'s paper deals with the tropical tropopause, I have their work at hand. That solves the second and third issues. By the way, I'm not only a meteorologist but also a scientist. Kind regards.--Jetstreamer ^Talk 02:21, 31 March 2012 (UTC)

Thanks. To me, it looks ok now (except for that 30000 value, I think that's too high according to several other sources). I believe you now, you know your stuff. When I saw your revert back to the erroneous version I had doubts. Cheers --Suaheli (talk) 02:58, 31 March 2012 (UTC)

Extraterrestrial tropopause

Hi Suaheli. I opted to try to solve the new issue that arose between you and me through this talk page. Both the stratosphere and troposphere are mentioned in the article as the tropopause is a boundary layer between these two layers. If you go to such articles you'll find that both of them deal with the Earth's atmosphere only. It is therefore not appropriate to mention the extraterrestrial tropopause in the article. Pleaselet me know what you think. Regards.--Jetstreamer ^Talk 22:21, 19 April 2012 (UTC)

I think the deletion is bureaucratic nonsense; whether it refers to the earth or not is secondary. The primary thing in a good description is to include the entire picture, the view from above, on the whole, of the physics in general, the interconnection between things. In this case here it's about a planetary effect. The earth is a planet. One of many. The effect does not only occur at home in the kitchen. The text you deleted set an interesting bridge from the existing facts in the article to the overall picture. It was a very well start, an attempt that could be extended. Who are you that you delete this information although some people obviously find it useful. You've made strange edits already before. (By the way, the polar tropopause height you edited is still wrong, it should go down to 20000 ft, it's not limited to 30000). --Suaheli (talk) 00:37, 20 April 2012 (UTC)

Nothing about actual temperature?

The article has a lot to say about the derivative of air temperature with respect to altitude, since vanishing of the derivative is the basic concept behind the tropopause (pace the WMO procedure defining it more precisely). However nowhere does it say anything about the actual temperature at the tropopause, suitably averaged.

Since both surface temperature and troposphere altitude decrease with increasing latitude (in the sense of increasing angular distance from the equator), it is natural to ask which of these two effects dominates in determining the temperature of the tropopause as a function of latitude. In particular what is the annual average temperature of the tropopause at the equator, and at the poles? Vaughan Pratt (talk) 18:37, 28 February 2019 (UTC)

Tropopause folding

Needs a section on tropopause folding. Just granpa (talk) 19:10, 6 April 2019 (UTC)