Pre 1995 Persistent Contrail Archive

MikeC said:
Not sure if these are "persistent enough", but there are some quite substantial contrails off the canards of the XB-70 at 2.05 and 2.20 - just for a second or 2 each. I wonder if they are actually smoke for airflow indication?
Click to expand...
No.

The forewings of a canard aircraft suffer a higher wing loading than the rear wings so that near the stall the nose of the aircraft automatically lowers. That wing loading (when exploited sufficiently) will cause a sufficient pressure (and therefore temperature) drop at the tip vortices to form a temporary trail in certain atmospheric conditions.

When the XB70 was lost (by one of its tailfins colliding with a Starfighter chaseplane) it went into a flat spin and a complete cloud formed above the whole aircraft as it fell.
 
Five minutes looking. 1977.

http://www.flickr.com/photos/30159472@N04/5715276757/

contrailscience.com_skitch_1977._Dad_and_my_old_brother_at_the6121519796ff9197c83975b95b046d9a.jpg


http://www.flickr.com/photos/30159472@N04/5715841370/in/photostream/
contrailscience.com_skitch_1977._My_dad_and_my_old_brother_in_c55e53e20d74863a14520608238b4a45.jpg

contrailscience.com_skitch_1977_20121102_122332.jpg
 
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A Schoolar Poster about Contrails made by "Deutsche Zentrum für Luft- und Raumfahrt e. V. " (DLR) from the year 1989.

(Dont´ be confused about the sligthly changed name behind "DLR", they had changed their name a little bit)

www.abload.de_img_chn8oa3.jpg


I´ve searched a readable version for a long time , now i found it again...

https://www.metabunk.org/metamirror_cache/www.abload.de_img_chn8oa3.jpg
 
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I was browsing in a second hand bookstore today and found this:

Life Magazine, Nov. 29, 1943, pp 69-83.
contrailscience.com_skitch_photo__282_29_20121229_160524.jpg


Looked it up when I got back. It was an air-force book, partially reprinted in Life.

View attachment Target Germany.pdf

Also has this small image:
contrailscience.com_skitch_LIFE___Google_Books_20121229_163141.jpg

And mentions of vapor trails:
contrailscience.com_skitch_LIFE___Google_Books_20121229_163329.jpg

contrailscience.com_skitch_LIFE___Google_Books_20121229_163454.jpg


There's also a video with the same name that seems to have some close-up shots of a contrail from above, as well as some conventional contrails video.
http://www.youtube.com/watch?v=5hp0x80fqOU

contrailscience.com_skitch_Target_Germany__281945_29___YouTube_20121229_161856.jpg

contrailscience.com_skitch_Target_Germany_20121229_161941.jpg
 
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Mick said:
View attachment 1303



There's also a video with the same name that seems to have some close-up shots of a contrail from above, as well as some conventional contrails video.
http://www.youtube.com/watch?v=5hp0x80fqOU

contrailscience.com_skitch_Target_Germany__281945_29___YouTube_20121229_161856.jpg
Click to expand...

I am not sure that this particular one is a contrail - for the few seconds it is in the video it sems to get smaller, which makes me think it might be a smoke marker.

the following text explains how they were used:

External Quote:
When the lead bombardier's Norden bombsight released his bombs, two smoke bomb were released from below the chin turret. When the rest of the squadron bombardiers or toggleers saw the smoke bombs released we then hit the SALVO switch and released our bombs also. Of course, milli-seconds later we would have seen the actual explosive bombs falling from the bomb-bay but in an attempt to group the bombs on target we needed to release them ALMOST at the same time the lead bombardier released his bombs.
From here - http://goodsky.homestead.com/files/deception5.html

Earlier in the video you can see smoke trails ending in bombed areas - these are very distince single trails, as opposed to smoke screens from the ground.
 
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These are two great ones...

Number one: From the german Nazi-Propaganda Magazine "Der Adler", Year 1941, Number 6

DerAdler_HimmelsschriftDersKrieges.jpg

The title means "Skywriting at war" and the article discripes, how contrails are formed and that they could be used to find the Airplanes of the enemy.

Number Two: Script of a Scientific Lession for "german Academy for Aviation-Science (1940)".

The Article´s name is "Die Entstehung von Eisnebeln aus den Auspuffgasen von Flugmotoren"
(The formation of icy-clouds due to Evapurations of Airplane-Engines)

This is a more scientific analysis how contrails are made and under what conditions they stay permanemt. Compareable to the "Color of Clouds"-Book from 1972. Take a look to this graph, showing under wich conditions contrails are persistant;

TEmp.jpg

"Wolkenschweife" means "contrails".
X-Axis is temperatur in celsius. Y-Axis is relative humidity.
Black squares are Flligths without any contrail.
Circles are Fligths with a short contrail under 300 meter
"+"-Sings are Contrails between 300 and 1000 meters
black circles are contrails longer than 1000 meters

Some other captures from this early WW2-Paper:

TEmp.jpg

TEmp.jpg


You can donwload the PDFs to both articles here:

First Article:
Der Adler, 1941 Heft 6, Über die Entstehung von Kondensstreifen
http://chemtrail-fragen.de/der_adler_1941_heft_6_ueber_die_entstehung_von_kondensstreifen.pdf

Second article:
Die Entstehung von Eisnebel aus den Auspuffgasen von Flugmotoren
Ernst Schmidt, 1940, Deutsche Akademie der Luftfahrtforschung
http://chemtrail-fragen.de/ernst_schmidt_1940_deutsche_akademie_der_luftfahrtforschung.pdf

Somebody who has better english-skills than me should translate these documents from World-war-2.
 
It would imply that if enemy planes were being able to follow the contrails back to their source, that they were Persistent and long lasting.
 
FreiZeitGeist, did you notice that the two photos on "page 21" of your Number Two have been cropped out of the top right photo on "page 160", your Number One?
 
I assume the article in the "Adler" magazine is based on the paper by Ernst Schmidt.

Here is my shot at translating the interesting part in that paper (pg. 19 and 20). For references to "DFS", see Wikipedia

The problem of sublimation and condensation in supersaturated layers low on nuclei could be solved only to a small degree. It seems however that supersaturated conditions without condensation and sublimation are not as frequent as A. Wegener has assumed. Some of the phenomenons observed by Wegener are likely to have been caused by influx of water vapor. On their high-level flights, the DFS is conducting experiments with injection of hydroscopic and non-hydroscopic nuclei in the upper troposphere. No unambigious results have been found yet. The experiments are suffering from the impossibility to measure water vapor saturation properly at low temperatures.

Based on the experiences about cloud trail formation behind airplanes to date, the DFS has issued a leaflet for the battlefront. Slow planes are more likely to create cloud trails than fast planes. With short cloud trails, alternating between full and reduced throttle affords a certain level of protection. If long and persistent cloud trails are forming, climbing and gliding flight has to be employed in turns.

The problem in question has further relevance with regard to conditions for ice accretion. Jaumotte has pointed out an interesting case which is associated with the phenomenons described here. Above a rain and hail cloud at around 5000 m altitude, a 6 to 10 cm layer of ice formed on a plane in an area that was entirely clear. The reported thickness of the ice seems exaggerated, however the incident implies that above the cumulus cloud there must have been a clear layer with high supersaturation which was made unstable by the airplane, causing rapid icing.

This case closely resembles the accident of three Italian planes near Lucca. In 1939, on December 6th three planes of the Italian air force crashed due to ice accretion. The planes were part of a larger squadron flying at 3000 m altitude above the clouds, within sight of each other. The planes flying in the middle of the group were creating veritable snow clouds, more accurately ice cloud trails, when they passed between two towering clouds. The following planes crashed when they passed that area, quite obviously due to icing. It is likely that the cause has been heavy supersaturation prevailing between those two high-reaching clouds which was amplified and "triggered" by the preceding planes, so that the trailing planes suffered sudden and rapid ice accretion.

These cases are showing how scant our knowledge is about the supersaturated layers which exist in the atmosphere, and how significant the experiments conducted to research the meteorologic conditions of the upper troposphere are with respect to the safety of aviation. However, major progress can only be expected once the problem of exact humidity determination at low temperatures is solved, by methods that can be handled easily.
 
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An example of a persistent spreading contrail from the book "Aeronautical Meteorology" by Matveev and Smirnov, 1955 (Part 1). The book can be downloaded here: http://u8239182.letitbit.net/download/19610.1bd4a7628d527952a0c1cf648576/192923.rar.html.

Облачный след.PNG

The translation of contrail chapter:

External Quote:
Condensation and sublimation of water vapor in the atmosphere lead to the formation of so-called contrails after a flying plane.
Observations show that contrails are formed in the troposphere at temperatures lower than -30...-40 degrees.
Contrails are formed due to sublimation of water vapor, which is the result of combustion of aircraft fuel (gasoline, kerosene) getting into the atmosphere. The effect of pressure drop under an airplane's wing due to faster air motion (Bernulli's law) contributes considerably to contrail formation. The decrease of pressure leads to decrease of temperature (the process is adiabatic). If the air at the flight's height is close to saturation, the additional temperature drop under a wing will cause condensation and contrail formation. Extra condensation nuclei originated from non-combusted particles of fuel contribute to the process. Observations show that contrails form in regions which are close to saturation over ice. This fact along with additional water vapor and condensation nuclei from an airplane produce a persisting contrail.
Another fact is that persisting contrails form in the regions with cirrus clouds or light haze (which may not be visible from the ground) in the upper troposphere. When air is unsaturated (over ice), contrails will rapidly dissolve because of turbulence. The trails usually form after each engine. Later they merge into a single one. Contrails may also be formed after an aircraft's wing due to flow underpressure and jet disruption.
 
CbIncus said:
An example of a persistent spreading contrail from the book "Aeronautical Meteorology" by Matveev and Smirnov, 1955 (Part 1). The book can be downloaded here: http://u8239182.letitbit.net/download/19610.1bd4a7628d527952a0c1cf648576/192923.rar.html.

View attachment 2446

The translation of contrail chapter:

External Quote:
Condensation and sublimation of water vapor in the atmosphere lead to the formation of so-called contrails after a flying plane.
Observations show that contrails are formed in the troposphere at temperatures lower than -30...-40 degrees.
Contrails are formed due to sublimation of water vapor, which is the result of combustion of aircraft fuel (gasoline, kerosene) getting into the atmosphere. The effect of pressure drop under an airplane's wing due to faster air motion (Bernulli's law) contributes considerably to contrail formation. The decrease of pressure leads to decrease of temperature (the process is adiabatic). If the air at the flight's height is close to saturation, the additional temperature drop under a wing will cause condensation and contrail formation. Extra condensation nuclei originated from non-combusted particles of fuel contribute to the process. Observations show that contrails form in regions which are close to saturation over ice. This fact along with additional water vapor and condensation nuclei from an airplane produce a persisting contrail.
Another fact is that persisting contrails form in the regions with cirrus clouds or light haze (which may not be visible from the ground) in the upper troposphere. When air is unsaturated (over ice), contrails will rapidly dissolve because of turbulence. The trails usually form after each engine. Later they merge into a single one. Contrails may also be formed after an aircraft's wing due to flow underpressure and jet disruption.
Click to expand...


The pressure drop is over the top of the wing. Must be a typo or an error with the translation.
High pressure moves to low pressure giving way to lift.
 
Thank you justanairlinepilot for pointing out this detail. I've checked the original source in Russian and there is told about the drop of pressure and temperature under the wing (I think the authors speak about engines). The drop above the wing is higher and this is the cause of airplane's lift.
 
Back to topic...

Some early Contrail-Pictures from the GDR
(German Democratic Republic, most known as "East-Germany")

collected by Allmystery-User Mr. Q

Postcard with a IL-14 used by "Interflug" until 1963, so this picture must be taken earlier

taef65a_IL-14-1966.jpg

Postcard showing the Mitropa-Hotel near Airport Schönefeld, taken in early 70s

tf06b6a_Postkarte_Mitropa_1971_resize.jpg

Some "Haarp-Clouds" Over Berlin Schönefeld from the 70s (Yes, the GDR seems to be very progressive in secret weather-warfar ;-)

t68cd43_Postkarte_TU3_IL18_1970_resize.jpg



2 Postcards from West-Berlin from the 60s

tbdfbfd_KGrHqVikE6JfP2oYhBOkwKmvr560_12.JPG

t484d23_670555.jpg
 
[NOTE: This thread is JUST for posting photos and video, and immediate commentary on them. Off topic or long discussions will be deleted or moved]

OT Posts moved to:https://www.metabunk.org/threads/1757-Weather-Modification-in-Wikileaks-Contrails-vs-Chemtrails-Etc
 
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A quote from an old Sovietic book called "Aeronautical Meteorology" by M. A. Babikov (1951). Unfortunately there's no photo in it, so feel free to move my post.

PDF link: http://firstep.ru/library/TechnicalBooks/AviaMeteorology.pdf (page 27).

Vast amounts of condensation nuclei exist in lower layers of the troposphere, but at higher layers (at altitude 5 km and above) they should be less numerous. When planes fly at high altitudes, a persistent trail can be frequently seen in the sky. This phenomena can be explained by saturated and supersaturated layers which exist there without condensation or sublimation nuclei. The aircraft entering such a layer can introduce them as products of fuel burning, rapidly achieving condensation.
Click to expand...

The book has a misunderstanding of condensation and sublimation nuclei (the author writes about them as about two different things). It has been shown later that they are the same.
 
Some images from Sovietic Cloud Atlas by Hrgian and Novojilov (1978).

contrail_01.png contrail_02.png

http://elib.rshu.ru/files/img-214103409.pdf (read pages 49-50)

Translation of the caption:

The trails (1, 2) which were probably formed 15 to 30 mins. before the photography was done expanded and now look like sheep skin; the trail (3) formed later and reminds a band in the sky. The cirrus clouds behind possibly developed from earlier trails. WMO Cloud atlas code: 200.

It's a good evidence of "chemtrails" over non-NATO countries and their transforming to cirrus clouds.
 
CbIncus said:
The book has a misunderstanding of condensation and sublimation nuclei (the author writes about them as about two different things). It has been shown later that they are the same.
Click to expand...

Actually, condensation nuclei (CCN, cloud condensation nuclei) and sublimation nuclei (IN, ice nuclei) are different.

There are cloud condensation nuclei everywhere in the atmosphere. This is why it is so hard to get water supersaturation in the atmosphere. As soon as conditions get to water saturation, the vapor condenses on the abundant CCN to form a cloud of water droplets.

There are essentially no ice nuclei (sublimation nuclei) in the atmosphere. This is precisely why areas of ice-supersaturation can exist for long periods of time.

In the Russian book, it would have been sufficient to say,
This phenomena can be explained by saturated and supersaturated layers which exist there without sublimation nuclei.
Click to expand...

It is misleading to say "without condensation nuclei" because these are everywhere in the atmosphere.
 
And CCN and IN are different because of their molecular structures. For water to condense or accrete on the surface it needs to fit the molecular structure. Different substances have surface molecular geometries that are better suited for either water or ice. Since ice is a crystal it's got more exacting requirements.

There may be some confusion because ice clouds can form on CCN, but they form first as liquid water, which then freezes into a crystal form, which then acts as and IN, then accretes - not directly into ice. This is the dominant mechanism for contrail formation.
 
Yes, the liquid water comes from condensation from some process that brings the air to water saturation.
In the case of cirrus formation, that mechanism is cooling by lifting; upward motion ahead of a front, in the vicinity of a jetstream (warm die of the core), convection.
In the case of contrail formation the mechanism is mixing with hot, moist jet exhaust.
 
Ross Marsden said:
Actually, condensation nuclei (CCN, cloud condensation nuclei) and sublimation nuclei (IN, ice nuclei) are different.

There are cloud condensation nuclei everywhere in the atmosphere. This is why it is so hard to get water supersaturation in the atmosphere. As soon as conditions get to water saturation, the vapor condenses on the abundant CCN to form a cloud of water droplets.

There are essentially no ice nuclei (sublimation nuclei) in the atmosphere. This is precisely why areas of ice-supersaturation can exist for long periods of time.
Click to expand...

Thank you for this information! I've been searching for something like this for a long time!
 
Observation of a persistant Contrail from the Year 1919

from
"Wolkenbildung durch ein Flugzeug"
(in: Naturwissenschaften , ISSN 1432-1904, Vol. 7 (34. 1919), Page 625)

contrail1919.jpg

Source: http://www.digizeitschriften.de/dms/img/?PPN=PPN34557155X_0007&DMDID=dmdlog408

the most important parts in plain text

External Quote:

Wolkenbildung durch ein Flugzeug

Am 11. Mai d. J. wurde in München die Aufmerksamkeit des Publikums durch einen Wolkenstreifen gefesselt, der sich hinter einem Flugzeug bildete, das in sehr großer Höhe flog.

Das Flugzeug war gestartet um 9 Uhr 46 Min. Um 10 Uhr 40 Min. war ein feiner Streifen zu beobachten, der in der Richtung des Flugzeuges sich fortpflanzte, so daß das Flugzeug immer den Kopf der Erscheinung bildete.

[...]

Allmählich verbreiterte sieh das Gebilde und nahm eine senkrecht zur Längserstreckung wellenförmige Struktur an oder, wie sich sehr anschaulich ein Beobachter ausdrückte, "es glich einem Schlangenskelette". Man sah jede einzelne Wirbelgruppe des Auspuffs in wunderbar klarer Ausbildung. Die einzelnen "Wirbel" des Skeletts traten in regelmäßigen Abständen auf. Schließlich entwickelte sieh das ganze Band zu einer regelrechten Cirruswolke; um 11 Uhr 40 Min. trat die Erscheinung eines Sonnenrings auf, der sich in dem Augenblicke entwickelte, als die Wolke die Sonne passierte.

[...]

Die Wolke zog mit mäßiger Geschwindigkeit in östlicher Richtung ab, wobei sie immer mehr das Aussehen einer normalen Cirruswolke annahm und alles Auffällige verlor.

[...]

München, den 21. Juni 1919
L.Weickmann
... translated with google:

External Quote:
Formation of clouds through an airplane

On 11 May of this year was in Munich tied the attention of the audience through a cloud streaks that formed behind an airplane that flew in very high altitude.

The aircraft took off at 9:46 am. At 10:40 am there was observed, a fine strip propagated in the direction of the aircraft, so that the aircraft always formed the head of the phenomenon.

[...]

Gradually broadened check the structure and took a perpendicular to the longitudinal extension wavy structure or, as one observer put it very clearly, "it was like a snake skeletons." They saw each vertebral group of the exhaust in a wonderfully clear training. The single "vortex" of the skeleton occurred at regular intervals. Finally see the whole band developed into a regular cirrus cloud, by 11:40 am took the appearance of a sun ring on that developed at the moment, as the cloud crossed the sun.

[...]

The cloud moved with a moderate speed in an easterly direction, it took more and more the appearance of a normal cirrus cloud and lost all conspicuous.

[...]

Munich, 21 June 1919
 
Translation to natural English

External Quote:
Formation of clouds by an airplane

On 11 May of this year, in Munich, the attention of the audience was drawn to cloud streaks that formed behind an airplane that flew at very high altitude.

The aircraft took off at 9:46 am. At 10:40 am there was observed a fine strip propagating in the direction of the aircraft, so that the aircraft always formed the head of the phenomenon.

[...]

The structure gradually widened and took on a wavy structure perpendicular to its length or, as one observer put it very clearly, "it was like a snake skeleton." They saw each vertebral group of the exhaust in a wonderfully clear formation. The individual "vertebra" of the skeleton occurred at regular intervals. Finally the whole strip was seen to develop into a regular cirrus cloud, by 11:40 am it took the appearance of a sun ring that developed as the cloud crossed the sun.

[...]

The cloud moved with a moderate speed in an easterly direction, it took more and more the appearance of normal cirrus cloud and became inconspicuous.

[...]

Munich, 21 June 1919
 
Two articles from Meteorological Dictionary by Khromov and Mamontova (1974).

External Quote:
Airplane trails

Artificial cirrus clouds which form behind airplanes in upper troposphere and lower stratosphere; their structure is similar to Cirrocumulus clouds; the international name: Cirrus tractus (Ci tr.). They are often observed in conditions favourable for cirrus clouds formation; and cirrus usually cover a part of the sky (even a small one). The formation of airplane trails is generally caused by water vapour in the exhaust (condensation trails); another reason is dynamic pressure decrease in vortices running off from wings and propellers and adiabatic temperature drop (aerodynamic trails).

Synonym: cloud trails.
External Quote:
Aerodynamic trails

Airplane cloud trails caused by adiabatic cooling of air to saturation or slight supersaturation when it is flowing around the wing. They are relatively rare and non-durable when compared to airlane trails.
 
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