Jet Pilots Fear "Chemtrail" Attacks

Any time there is any blue sky in EITHER place it is soon obscured by these so-called persistent contrails. A totally blue sky is like a blue moon, and most of the "clouds" on many days, as I know from 3 years of daily observation, are not real.

Then a jet flies over, the contrail persists, becomes a cirrus-type cloud, then another jet flies over, leading to another cirrus-type "cloud", and on and on it goes....ALL FREAKING DAY! Dozens of jets laying parallel trails. By mid-day there is a thick haze, and if you spend as much time outdoors as I do, you will no that very few of those "clouds" are natural. Often we see completely overcast skies SOLELY, 100% from jet "contrails". That is not normal! We used to have blue sky in the summer! This is the geoengineering they have been "proposing", only it isn't a proposition, it is happening now!

Would you please tell us your approximate location within 20 miles or so. There is a way we can show you what flies over just about any area, and will have a look.

I have been watching these threats for years now. They are accelerating. A movie was produced which told people a holocaust was happenng, and they wee being poisoned. Those are provocative statements, "fighting words". Even though you may be peaceful, others are not. Just look at peekay22's youtube video. He claimed to be peaceful, but could not stop others from making threats on his own channel. Yes, it would paint all chemtrail activists with a broad brush, but yet even Michael J. Murphy allows such threats to be made reguarly on his facebook page. He was the ne saying that people are being sprayed with poison, that a "Crime Against Humanity" was taking place. What in the world is he thinking?
 
No . . . how does the climate changes effect persistent contrail and cirrus cloud formation . . . ??

They cleverly conceal that information in things such as books, etc.
It's a conspiracy to hide information from those who don't want to do research.
 
They cleverly conceal that information in things such as books, etc.
It's a conspiracy to hide information from those who don't want to do research.

Lol . . . so are you saying there is more moisture in the high troposphere and lower stratosphere because of warming? Are you saying the temperature of the upper troposphere is warmer and the stratosphere is colder . . . so this means what . . . more persistent contrails in the stratosphere but fewer in the troposphere . . . ? Seems very negligible to me . . . I have never seen any publication which included the above discussion or speculation about the persistence of contrails based on global warming . . .


Seems very complex to me . . .



Recent discussions of climate change (MSU Temperature Record, ACIA) have highlighted the fact that the stratosphere is cooling while the lower atmosphere (troposphere) and surface appear to be warming. The stratosphere lies roughly 12 to 50 km above the surface and is marked by a temperature profile that increases with height. This is due to the absorbtion by ozone of the sun’s UV radiation and is in sharp contrast to the lower atmosphere. There it generally gets colder as you go higher due to the expansion of gases as the pressure decreases. Technically, the stratosphere has a negative ‘lapse rate’ (temperature increases with height), while the lower atmosphere’s lapse rate is positive.
http://www.realclimate.org/index.ph...stratosphere-cool-when-the-troposphere-warms/
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Recent analyses of temperature trends in the lower and mid- troposphere (between about 2,500 and 26,000 ft.) using both satellite and radiosonde (weather balloon) data show warming rates that are similar to those observed for surface air temperatures. These warming rates are consistent with their uncertainties and these analyses reconcile a discrepancy between warming rates noted on the IPCC Third Assessment Report (U.S. Climate Change Science Plan Synthesis and Assessment Report 1.1).

An enhanced greenhouse effect is expected to cause cooling in higher parts of the atmosphere because the increased "blanketing" effect in the lower atmosphere holds in more heat, allowing less to reach the upper atmosphere. Cooling of the lower stratosphere (about 49,000-79,500 ft.) since 1979 is shown by both satellite Microwave Sounding Unit and radiosonde data (see previous figure), but is larger in the radiosonde data likely due to uncorrected errors in the radiosonde data.
http://www.ncdc.noaa.gov/cmb-faq/globalwarming.html

Content from External Source

Is The Stratosphere Responsible For Global Warming?

Nataliya Kilifarska of the National Institute of Geophysics, Geodesy and Geography, in Sofia, Bulgaria, presents a powerful analysis that confirms a strong relationship between stratospheric ozone and land air temperature.
http://junkscience.com/2012/05/17/is-the-stratosphere-responsible-for-global-warming/

She says that this highly significant relation raises the question about the nature of the influence, and suggests that it operates through control over the temperature and humidity in the upper troposphere/lower stratosphere by ozone variations. The ozone variability itself is initiated by variations in Galactic Cosmic Ray (GCR) intensity, which produces O3 at these levels. GCRs are in turn mediated by the Sun. An important point is that the high effectiveness of this mechanism is due to the fact that small fluctuations of the H2O vapour (in the most arid regions of the troposphere) influences the radiation balance of Earth in a highly non-linear way meaning small changes in the Sun results in a big change in Earth’s temperature.

Content from External Source

Ken Minschwaner, a physicist at the New Mexico Institute of Mining and Technology, Socorro, N.M., and Andrew Dessler, a researcher with the University of Maryland, College Park, and NASA’s Goddard Space Flight Center, Greenbelt, Md, did the study. It is in the March 15 issue of the American Meteorological Society’s Journal of Climate. The researchers used data on water vapor in the upper troposphere (10-14 km or 6-9 miles altitude) from NASA’s Upper Atmosphere Research Satellite (UARS).
Their work verified water vapor is increasing in the atmosphere as the surface warms. They found the increases in water vapor were not as high as many climate-forecasting computer models have assumed. “Our study confirms the existence of a positive water vapor feedback in the atmosphere, but it may be weaker than we expected,” Minschwaner said.
http://earthobservatory.nasa.gov/Newsroom/view.php?id=24432

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And then you did. Bravo.
No . . . I still have not . . . IMO seems the relationship would be very speculative . . . about the same as saying persistent contrails and their contrail induced cirrus clouds cause significant global warming and thereby produce more persistent contrails . . .

I have seen it stated that the amount of water vapor added into high frequency, high altitude air lanes by prior traffic which lingers and is enough to make suboptimal air optimal for persistent contrail formation . . .
 
No . . . I still have not . . . IMO seems the relationship would be very speculative . . . about the same as saying persistent contrails and their contrail induced cirrus clouds cause significant global warming and thereby produce more persistent contrails . . .
I have seen it stated that the amount of water vapor added into high frequency, high altitude air lanes by prior traffic which lingers and is enough to make suboptimal air optimal for persistent contrail formation . . .
You have seen it. My point really. Whether or not you can put a workable interpretation on what you see would be speculation on my part.

The science involved in the atmosphere is not speculative. It will do what it must without a moment's debate. If you understand the science then you will not be speculating.

Contrails don't cause significant GW. Flying through a stratospheric layer will humidify it. Flying through a supersaturated stratospheric layer will dehumidify it.

It stands to reason.
 
A 747-400 adds an average of approx 14 tonnes of water per hour to the atmosphere, based on a average cruise fuel flow of 10 tonnes per hour. In early cruise at heavy weights it is 16 tonnes per hour. A 767 adds about 8 tonnes an hour. An Airbus A330 about 9. 737's and A320's add about 3 each.
 
Yet again you miss the point - the point is not that he knows - it is that he is not SPECULATING.
 
Yet again you miss the point - the point is not that he knows - it is that he is not SPECULATING.
And you are all missing a significant POINT . . . if it is TRUE . . . global warming has increased the frequency of persistent contrails and contrail induced cirrus cloud banks, in the stratosphere, then this becomes evidence of at least two important concepts . . .

1) It is one more piece of evidence global warming exists
2) It is one more piece of evidence that Chemtrail supporters are seeing an increase in persistent contrails and contrail induced cirrus clouds because of a natural process . . . thereby reducing the anger of some supporters toward pilots and aircrews. . .

As I said in #85 above

I have never seen any publication which included the above discussion or speculation about the persistence of contrails based on global warming . . .
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Seems we have the following reasons for increased persistent contrails and cirrus cloud banks . . . which are either fact or speculation . . .

1) More aircraft flying and more frequently . . . Fact
2) More aircraft flying at higher altitudes . . . especially commercial and military . . . Fact
3) Larger and more powerful engines . . . Fact
4) More efficient engines . . . Fact
5) Global Warming increases moisture and decreases temperature in Stratosphere . . . leading to more persistent contrails . . . Speculation
 
Global Warming increases moisture and decreases temperature in Stratosphere . . . leading to more persistent contrails . . . Speculation
Well, it actually does (increase moisture in the troposphere, and decrease temperature in the stratosphere*)**. There's no speculation at all, except to its degree...

Coupled with the points above, it also becomes a fact.

* It will be different when there are no more icecaps and glaciers left to melt. And different again when polar permafrosts go. And different again when ocean clathrates*** decompose. Am I speculating? :(

** The solar energy retained moment-by-moment by the moment-by-moment increase in atmospheric CO2 has already been calculated. It is massive amount.

Such energy increase is kinetic - as is temperature - and results in an increase of the average global atmospheric wind speed, and also a reduction in average global air pressure. Temporary, I think, because water vapor and dissolved CO2 will emanate from the oceans in response to this.

The reduction in temperature in the stratosphere is presently brought about by heat transfer (the latent heat of fusion of ICE) from the poles, glaciers, and mountaintops, which are generally higher. (The tropopause is lower at the poles than at the equator.)

So at present we're in a temporary fool's paradise... ...and that's my firm conviction.

*** Ocean clathrates are a time bomb for any intelligent civilization, on any blue planet in any goldilocks zone around any star in the Universe, which believes it can use fossil fuels without let or hindrance.

The speed of release of carbon dioxide from fossil fuels is determined by the civilization and could be slowed and stopped with some effort.

The speed of release of methane from melting permafrost can be slowed and reversed by dint of great effort.

The release of stored methane from ocean clathrates will be an instant and irreversible catastrophe.
 
Well, it actually does (increase moisture in the troposphere, and decrease temperature in the stratosphere*). There's no speculation at all, except to its degree...

Coupled with the points above, it also becomes a fact.

* It will be different when there are no more icecaps and glaciers left to melt. And different again when polar permafrosts go. And different again when ocean clathrates decompose. Am I speculating? :(
The speculation is . . . are these FACTS capable of increasing the prevalence of persistent contrails and cirrus cloud banks . . . that is . . . are the changes from Global Warming part of the reason people are seeing more trails in the sky . . .
 
I see that the original topic of this thread has been discussed at GLP, where the posters had no idea of the mass of ongoing threats. For a few days they were claiming that no threats had ever been made. Once Metabunk was linked to, they went practically silent.

http://www.godlikeproductions.com/forum1/message2039806/pg3

Sounds crazy to me . . . But the problem is how to engage in a constructive conversation with some of these people (thinking like they do) without having them dismiss you as a shill . . .
 
Yes. Next?
1) The first step is to construct a believable group of evidence that they will relate to without threatening their beliefs . . . this is not easy . . . something Like . . . "If I were managing a covert spraying program I would not want to call attention to my self . . ."
2) Next, one needs to develop a credible interaction with the group so your position will be considered and not immediately dismissed . . . this means validating some of their observations and agreeing that some things are not impossible but highly improbable . . . this is also very difficult . . . avoid condescending or high sounding scientifically laced explanations . . . never use term "Junior High School Science" or equivalent . . .
3) Being very, very patient in the face of attacks and personal insults . . .
 
1) The first step is to construct a believable group of evidence that they will relate to without threatening their beliefs . . . this is not easy . . . something Like . . . "If I were managing a covert spraying program I would not want to call attention to my self . . ."
2) Next, one needs to develop a credible interaction with the group so your position will be considered and not immediately dismissed . . . this means validating some of their observations and agreeing that some things are not impossible but highly improbable . . . this is also very difficult . . . avoid condescending or high sounding scientifically laced explanations . . . never use term "Junior High School Science" or equivalent . . .
3) Being very, very patient in the face of attacks and personal insults . . .
It sounds like you're relaying your personal experience. Here... LOL

Personally, I wouldn't be bothered.

The onus, I believe, is on the uninformed person to rise to the occasion. Not of the informed to go out of his or her way.

Consider it in terms of social effectiveness. It should be the purpose of the ignorant to educate themselves. We are all past the school stage, and it's about time we took the responsibility to be adult. We are all ignorant of something.

In this case these people believe they are informed. They need a short sharp shock. Many will respond to that. The remainder need moral persecution.
 
It sounds like you're relaying your personal experience. Here... LOL

Personally, I wouldn't be bothered.

The onus, I believe, is on the uninformed person to rise to the occasion. Not of the informed to go out of his or her way.

Consider it in terms of social effectiveness. It should be the purpose of the ignorant to educate themselves. We are all past the school stage, and it's about time we took the responsibility to be adult. We are all ignorant of something.

In this case these people believe they are informed. They need a short sharp shock. Many will respond to that. The remainder need moral persecution.
Sorry you feel that way . . . I personally identify with the underdog . . .
 
That's very kind of you. In my experience it wears off with time - the great grindstone. Maybe you're made of sterner stuff. :)
No, I have been the underdog much of my life so I sympathize . . . I think the intelligent, informed and educated have the obligation to lead . . . which means patience and taking a few hits occasionally . . .
 
The speculation is . . . are these FACTS capable of increasing the prevalence of persistent contrails and cirrus cloud banks . . . that is . . . are the changes from Global Warming part of the reason people are seeing more trails in the sky . . .

Asking a question "Are these facts capable...??...is not speculation - it is enquiry.

Speculation is "These facts ARE capable..."

The first is a reasonable question. The second is an (as yet AFAIK) unjustified conclusion.
 
Asking a question "Are these facts capable...??...is not speculation - it is enquiry.

Speculation is "These facts ARE capable..."

The first is a reasonable question. The second is an (as yet AFAIK) unjustified conclusion.
Whatever . . . my inquiry is as stated in #98 above . . . I made no conclusion . . . the conclusion was supplied by Billzilla in #73 . . .


- Climate change is subtly altering the atmosphere, again so that contrails are becoming more common and often lasting longer.
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http://www.thefreedictionary.com/_/dict.aspx?word=speculation
spec·u·la·tion
1.
a. Contemplation or consideration of a subject; meditation.
b. A conclusion, opinion, or theory reached by conjecture.
c. Reasoning based on inconclusive evidence; conjecture or supposition.


Content from External Source
 
The second is an (as yet AFAIK) unjustified conclusion.
It's justified in scientific terms. Just a question of degree...

...we are all faced with balancing that degree against the certainty of our exponential growth and use of fossil fuels.
 
Billzilla,

Seems the persistent contrail expert of experts thinks you are being a bit too enthusiastic with your conclusion . . . in fact, according to Dr Minnis there may be fewer persistent contrails due to global warming . . .


Good posts, Greg.
And as I've explained to Giselle before - but has fallen on deaf ears it would seem - there are two additional reasons why we are seeing more contrails these days.
- Modern jet engines run hotter (more efficient) than older ones and because of physics & chemistry that alone tends to make contrails more often and stronger than the older engines.
- Climate change is subtly altering the atmosphere, again so that contrails are becoming more common and often lasting longer.

None of this is a surprise if you do a few minutes research and have a bit of a think about how it all works.


Dear Mr. B,

I will try to answer your question below.

Patrick


On Nov 10, 2012, at 2:35 PM, George B wrote:




Dr Minnis


Question. . .Dr Minnis . . . Can one say that global warming is potentially responsible for \
an increase in persistent contrails and contrail induced cirrus cloud banks?


I doubt that slightly higher temperatures due to climate change are responsible for an increase in persistent contrails and induced cirrus.

Higher temperatures in the troposphere would raise the altitude necessary for contrail formation, so that there would likely be slightly fewer contrails rather than more.




If so, what percentage could it represent of the total of the following factors?

1) Increased number and frequency of flights overall at altitudes above 30,000 feet
2) Larger and more powerful engines
3) More efficient engines
4) Global Warming



If there is more moisture in the high troposphere and lower stratosphere because o fwarming . . . and the temperature of the upper troposphere is warmer and the stratosphere is colder . . . so can this means . . . more persistent contrails in the stratosphere but fewer in the troposphere . . . ? Seems very negligible to me . . . I have never seen any publication which included the above discussion or speculation about the persistence of contrails based on global warming . . .see research cites below . . .


Persistent contrails rarely ever form in the stratosphere because it is too dry. A slight increase in humidity will not be sufficient to change this negligible frequency. More moisture in the upper troposphere could possibly lead to thicker contrails, but not more of them.






Thanksfor your time

"Recent discussions of climate change (MSU Temperature Record, ACIA) have highlighted the fact that the stratosphere is cooling while the lower atmosphere (troposphere) and surface appear to be warming. The stratosphere lies roughly 12 to 50 km above the surface and is marked by a temperature profile that increases with height. This is due to the absorbtion by ozone of the sun’s UV radiation and is in sharp contrast to the lower atmosphere. There it generall ygets colder as you go higher due to the expansion of gases as the pressure decreases.Technically, the stratosphere has a negative ‘lapse rate’ (temperature increases with height), while the lower atmosphere’s lapse rate is positive."
http://www.realclimate.org/index.php...osphere-warms/

"Recent analyses of temperature trends in the lower and mid- troposphere (between abou t2,500 and 26,000 ft.) using both satellite and radiosonde (weather balloon) data show warming rates that are similar to those observed for surface air temperatures. These warming rates are consistent with their uncertainties andt hese analyses reconcile a discrepancy between warming rates noted on the IPCC Third Assessment Report (U.S. Climate Change Science Plan Synthesis and Assessment Report 1.1).

An enhanced greenhouse effect is expected to cause cooling in higher parts of the atmosphere because the increased "blanketing" effect in the lower atmosphere holds in more heat, allowing less to reach the upper atmosphere. Cooling of the lower stratosphere (about 49,000-79,500 ft.) since 1979 is shownby both satellite Microwave Sounding Unit and radiosonde data (see previous figure), but is larger in the radiosonde data likely due to uncorrected errors in the radiosonde data."
http://www.ncdc.noaa.gov/cmb-faq/globalwarming.html

"IsThe Stratosphere Responsible For Global Warming?

Nataliya Kilifarska of the National Institute of Geophysics, Geodesy and Geography, in Sofia, Bulgaria, presents a powerful analysis that confirms a strong relationship between stratospheric ozone and land air temperature.

She says that this highly significant relation raises the question about the nature of the influence, and suggests that it operates through control over the temperature and humidity in the upper troposphere/lower stratosphere by ozone variations. The ozone variability itself is initiated by variations in Galactic Cosmic Ray (GCR) intensity, which produces O3 at these levels. GCRs are in turn mediated by the Sun. An important point is that the high effectiveness of this mechanism is due to the fact that small fluctuations of the H2O vapour (in the most arid regions of the troposphere) influences the radiation balance of Earth in a highly non-linear way meaning small changes in the Sun results in a big change in Earth’s temperature."
http://junkscience.com/2012/05/17/is...lobal-warming/

"Ken Minschwaner, a physicist at the New Mexico Institute of Mining and Technology,Socorro, N.M., and Andrew Dessler, a researcher with the University of Maryland, College Park, and NASA’s Goddard Space Flight Center, Greenbelt, Md, did the study. It is in the March 15 issue of the American Meteorological Society’s Journal of Climate. The researchers used data on water vapor in the uppe rtroposphere (10-14 km or 6-9 miles altitude) from NASA’s Upper Atmosphere Research Satellite (UARS).
Their work verified water vapor is increasing in the atmosphere as the surface warms. They found the increases in water vapor were not as high as many climate-forecasting computer models have assumed. “Our study confirms theexistence of a positive water vapor feedback in the atmosphere, but it may beweaker than we expected,” Minschwaner said. "
http://earthobservatory.nasa.gov/New...w.php?id=24432

Sent from my iPad


YoursTruly

GeorgeB
ColonelUSAF Retired

***************************************************************************************
Patrick Minnis, PhD
MS 420
NASA Langley ResearchCenter
Hampton, VA, USA23681-0001
phone: 757-864-5671 fax: 757-864-7996 email: Patrick.Minnis-1@nasa.gov
homepage: http://www-pm.larc.nasa.gov
"humilitas estveritas"
*****************************************************************************************



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Cooling of the lower stratosphere (about 49,000-79,500 ft.) since 1979 is shown by both satellite Microwave Sounding Unit and radiosonde data (see previous figure), but is larger in the radiosonde data likely due to uncorrected errors in the radiosonde data.
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Actually THAT is the upper stratosphere in the temperate zones.

small fluctuations of the H2O vapour (in the most arid regions of the troposphere) influences the radiation balance of Earth in a highly non-linear way meaning small changes in the Sun results in a big change in Earth’s temperature
Content from External Source
That doesn't make sense. Perhaps "local atmospheric temperature" would make more sense here.

upper troposphere (10-14 km or 6-9 miles altitude) from NASA’s Upper Atmosphere Research Satellite (UARS)
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Is talking Equatorial. In the temperate zones these altitudes are much lower. Try not to be confused by this.

They found the increases in water vapor were not as high as many climate-forecasting computer models have assumed
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Which is itself a contradiction of what you claim Minnis said. They are still talking an increase in water vapor content, which is what I would expect.

An increase in water vapor is an increase in humidity - unless the temperature rises, and just above the tropopause the increased kinetic activity beneath actually makes it colder.

So there will be more trails as the globe warms - even if air travel weren't still growing exponentially.
 
Actually THAT is the upper stratosphere in the temperate zones.


That doesn't make sense. Perhaps "local atmospheric temperature" would make more sense here.


Is talking Equatorial. In the temperate zones these altitudes are much lower. Try not to be confused by this.


Which is itself a contradiction of what you claim Minnis said. They are talking an increase in water vapor content, which is what I would expect.

An increase in water vapor is an increase in humidity - unless the temperature rises, and just above the tropopause the increased kinetic activity beneath actually makes it colder.

So there will be more trails as the globe warms - even if air travel weren't still growing exponentially.

I am claiming only what he wrote . . . the red text above is Dr Minnis' words without change . . . I just changed the color for emphasis and clarification only . . . I sent him the email which was the quote above without his words in red . . . he then returned my email with his comments which are now in red . . . the quoted cited text were in the original email I sent him without change . . .

Dear Mr. B,

I will try to answer your question below.


Patrick

Content from External Source
I doubt that slightly higher temperatures due to climate change are responsible for an increase in persistent contrails and induced cirrus.

Higher temperatures in the troposphere would raise the altitude necessary for contrail formation, so that there would likely be slightly fewer contrails rather than more.

Content from External Source
Persistent contrails rarely ever form in the stratosphere because it is too dry. A slight increase in humidity will not be sufficient to change this negligible frequency. More moisture in the upper troposphere could possibly lead to thicker contrails, but not more of them.

Content from External Source
 
Billzilla,

Seems the persistent contrail expert of experts thinks you are being a bit too enthusiastic with your conclusion . . . in fact, according to Dr Minnis there may be fewer persistent contrails due to global warming . . .

Interesting, thanks for that.
I'd still like to see a few more opinions and data though.
 
Interesting, thanks for that.
I'd still like to see a few more opinions and data though.
I would like to think global warming would increase persistent contrails and contrail induced cirrus ; however, Dr Minnis is the man . . . he did indicate the one effect could be their appearance . . .

More moisture in the upper troposphere could possibly lead to thicker contrails, but not more of them.

Content from External Source
 
I would like to think global warming would increase persistent contrails and contrail induced cirrus ; however, Dr Minnis is the man . . . he did indicate the one effect could be their appearance . . .
More moisture in the upper troposphere could possibly lead to thicker contrails, but not more of them.
Content from External Source
Hardly relevant when the width of a single dense trail can exceed ten miles. There's no need to over-egg one's pudding.

Today's large turbofan engines do the job just nicely, handling sixteen times more air than the original gas turbines used for cruising the stratosphere. That'll be sixteen times more ice, of course. Nearly...

And you appear to be assiduously avoiding that the "lower stratosphere" altitudes mentioned were Equatorial, and not at all applicable to your speculation as to the dryness of the air where planes are actually cruising.

And you appear oblivious to the consequences of such trails, which is that they REMOVE water from the wet parts of the lower stratosphere/tropopause to well below the tropopause. In effect they are drying the humid tropopause (if they are still growing in weight*) as they fall through it, to humidify the upper troposphere.

This will not normally mix back upwards with the lower stratosphere, so the movement of atmospheric water is predominately downward. Planes flying through over-saturated air at and above the tropopause DRY it, because gravity pulls the solid ice which is being formed downward. (With a low terminal velocity at first but that speed increases with the size of the ice crystal.)

This forms a flat and even cloud base where all the falling ice has evaporated back at a single isotherm. All that ice extracts first 80 cal/gm for fusion, and then 540 calls/gm for evaporation from the high troposphere/ground level. The temperature will be zero deg C. In very cold (clean air) conditions the trail will hit the ground, but only if the air remains saturated all the way down.. ...but saturation only occurs 17% of the time, and mostly around the tropopause**, where the air is at its coldest...

At the poles, these cold humid conditions may reach to ground level, but rest of the troposphere is being continually dried by dusts and other natural aerosols nucleating water droplets to fall as rain. Or, its air is being cleaned by its water vapor. Either will do.

* They could always meet, and I'm sure they often do, drier intervening layers, and evaporate before they get to the tropopause..

** 18,000 ft at poles, to 49,000 ft on the Equator, where planes crossing it have to navigate around cumulonimbus anvils, which rise two miles higher than they could ever fly. The air within such anvils is totally saturated, of course. It's a cumulonimbus trail of its own.
 
Hardly relevant when the width of a single dense trail can exceed ten miles. There's no need to over-egg one's pudding.

Today's large turbofan engines do the job just nicely, handling sixteen times more air than the original gas turbines used for cruising the stratosphere. That'll be sixteen times more ice, of course. Nearly...

And you appear to be assiduously avoiding that the "lower stratosphere" altitudes mentioned were Equatorial, and not at all applicable to your speculation as to the dryness of the air where planes are actually cruising.

And you appear oblivious to the consequences of such trails, which is that they REMOVE water from the wet parts of the lower stratosphere/tropopause to well below the tropopause. In effect they are drying the humid tropopause (if they are still growing in weight*) as they fall through it, to humidify the upper troposphere.

This will not normally mix back upwards with the lower stratosphere, so the movement of atmospheric water is predominately downward. Planes flying through over-saturated air at and above the tropopause DRY it, because gravity pulls the solid ice which is being formed downward. (With a low terminal velocity at first but that speed increases with the size of the ice crystal.)

This forms a flat and even cloud base where all the falling ice has evaporated back at a single isotherm. All that ice extracts first 80 cal/gm for fusion, and then 540 calls/gm for evaporation from the high troposphere/ground level. The temperature will be zero deg C. In very cold (clean air) conditions the trail will hit the ground, but only if the air remains saturated all the way down.. ...but saturation only occurs 17% of the time, and mostly around the tropopause**, where the air is at its coldest...

At the poles, these cold humid conditions may reach to ground level, but rest of the troposphere is being continually dried by dusts and other natural aerosols nucleating water droplets to fall as rain. Or, its air is being cleaned by its water vapor. Either will do.

* They could always meet, and I'm sure they often do, drier intervening layers, and evaporate before they get to the tropopause..

** 18,000 ft at poles, to 49,000 ft on the Equator, where planes crossing it have to navigate around cumulonimbus anvils, which rise two miles higher than they could ever fly. The air within such anvils is totally saturated, of course. It's a cumulonimbus trail of its own.


And you appear to be assiduously avoiding that the "lower stratosphere" altitudes mentioned were Equatorial, and not at all applicable to your speculation as to the dryness of the air where planes are actually cruising.

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The altitude or location of the stratosphere was not cited by Dr Minnis . . . the cited material was suplied by me which contained those facts . . . If you disagree with his (Dr Minnis') generalized statement . . . why not take it up with him . . . I assume you believe as tons water vapor from jet exhaust descend from the stratosphere through the tropopause that this along with the effects of global warming can increase the frequency of persistent contrails within the tropopause . . . is that what you are saying??
 
Today's large turbofan engines do the job just nicely, handling sixteen times more air than the original gas turbines used for cruising the stratosphere. That'll be sixteen times more ice, of course. Nearly...

Not really, the extra air is just air that helps the thermal efficiency, resulting in a cooler exhaust, which means a higher probability of contrail formation. The quantity of air used will not in itself affect the quantity of ice crystals formed. Now if it were to use 16 times more fuel, that would be another matter.

The spreading size of a contrail is not particularly related to the initial size either. If 100 feet grows to 10 miles wide, it does not mean 200 feet would grow to 20 miles wide. More like 10 miles plus 100 feet.
 
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