You occasionally see very pretty photos of contrails, like this one:

Very pretty.  But what is it?  It’s clearly not a regular exhaust contrail, as the trail seems to start actually ON the wing, and it has a weird rainbow effect you don’t often find in exhaust contrails.

It’s actually an aerodynamic contrail.  It’s formed by the reduction of pressure in the air as it moves over the wing.  When the pressure of a gas falls, then its temperature also falls (the same principle as is used by your refrigerator).  The reduced temperature cause small drops of water to condense, which then may freeze.  The (frozen) drops get larger as more water condenses on them.  The different sized drops (or ice crystals) have different optical properties, which affect different wavelengths of light, which accounts for the “rainbow” effect.

A rather more scientific explanation (also explaining the exact colors) can be found here:

http://contrailscience.com/files/Gierens_Aerodynamic_poster_060625.pdf

The interesting thing about this type of contrail is that they are actually more common in warm weather.   They need a lot of moisture, and cold air is generally dry, so they are more common in the summer months, and in warmer climes. See Aerodynamic Contrails Phenomenology and flow physics  – Gierens, et al.

As aerodynamic contrails are independent of the formation conditions of jet contrails, they form an additional class of contrails which might be complementary because they form in predominantly in layers that are too warm for jet contrail formation.

(They are not entirely complementary however, as you can get both types of contrail simultaneously from the same plane, see below.)

There is actually surprisingly little work being done on the formation of aerodynamic contrails.   A lot of the time they only show up as wingtip contrails (which you can see are very dense in the above photo).  Conditions need to be just right for the full wing to generate a contrail, and it typically does not last very long at all.

You’ve probably seen aerodynamic contrails on landing planes, like:

Here you can see the wing contrails vanish almost immediately.  The long persisting contrails (which won’t persist very long) are from the outer end of the lowered flaps – where air is compressed and then expanded very rapidly, causing a lot of moisture to condense.   You can also see there’s a lot of moisture in the air, it’s quite misty looking.

If the aerodynamic contrail is thick enough, then it forms like a solid sheet, and can curl up at the sides as it is drawn into the wingtip vortices:

http://www.airliners.net/photo/Cathay-Pacific-Airways/Boeing-777-267/2213426/L/&sid=0b512dfe498efba828a2189aca22fac6

 

This fantastic photo set on Flickr has some nice photos of both exhaust and aerodynamic contrails, you can clearly see the difference:

http://www.flickr.com/photos/jpro747/

In this shot, you can see the jet seems to be underneath a layer of clouds, suggesting it’s at a low altitude, where exhaust contrails would not normally form.  Although with this image, it’s little hard to see what is in front of what.  I suspect that the shadow you see near the tail is actually the shadow of the plane on the clouds, meaning the plane is just above them, or in them – in a region of high humidity, either way.

From the same set, we can see that the two types of contrail are not mutually exclusive.  You can have both at the same time:

Note you have the thick white contrails coming from the engine, and the aerodynamic contrails coming from the wings.

(side note here: most of the photos in jpro747′s set were taken FROM THE GROUND with a Canon 350D ($400) attached to a 1200mm 6-inch Dobsonian telescope ($300-$1000, depending on quality).   In most of the shots, you can clearly see the type of plane, and usually the airline markings.   Now, why has NOBODY in the supposed 2 Million “chemtrail” community managed to take a closeup photo of a jet spraying chemicalsConsidering you can do it with $700 worth of equipment, it seems rather odd).

This video shows an aerodynamic contrail forming in patchy air:

Aerodynamic Contrail in patchy air

You can see the trail looks very similar to the photos, especially in the final segment of the video.  There are few wide shots, so it’s hard to tell how long the trails is lasting for, but at 0:50, the camera pulls back, and the provious trail is either off screen, or has already evaporated.    Note this video was shot in Torino (Turin), Italy,on August 16th 2008 – during the summer.  That’s when these type of contrails are more likely, as they need very humid air.

(Update 9/24/2010)

Here’s a similar phenomenon. This is taken at a lower altitude, with the the sun just right.  This is a bit different as it’s not really a trail – or rather it’s a very short non persistent trail that only exists because of the extreme changes in air pressure from the F-22′s high power maneuvering.

Original source:

http://www.fencecheck.com/forums/index.php/topic,12042.msg203579.html#msg203579

And here’s an early photo, from LIFE magazine, October 4 1954

You can also get contrails from the tips of propellors

Here’s what it looks like from close up, following a KC_10:

Reference:

Aerodynamic Contrails Phenomenology and flow physics  – Gierens, et al.
Aerodynamic contrails Microphysics and optical Properties – Gierens, at al.

  108 Responses to “Aerodynamic and Rainbow Contrails”

  • Torino is in Italy, not Spain. Could you please correct this little mistake?
    By the way, nice website.

  • Thanks Calvin, I fixed it. Not sure where I was thinking of there.

  • “Very pretty. But what is it? It’s clearly not a regular exhaust contrail, as the trail seems to start actually ON the wing, and it has a weird rainbow effect you don’t find in exhaust contrails.”

    Hi Uncinus. There are TWO elements to what you see. The first (starting at the wing) is the aerodynamic element, as the pressure drop above the wing initiates the precipitation of fine ice crystals into the air. The second is the exhaust water from the jets which is condensing directly into ice crystals. The aircraft is flying high in a partly super-satured stratospheric layer, and the picture wasn’t taken from sea level – because the sky is BLACK. (I can appreciate that a modicum of photographic contrast and colour saturation modification has taken place.)

    “It’s actually an aerodynamic contrail. It’s formed by the reduction of pressure in the air as it moves over the wing. When the pressure of a gas falls, then its temperature also falls (the same principle as is used by your refrigerator). The reduced temperature cause small drops of water to condense, which then may freeze. The drops get larger as more water condenses on them. The different sized drops refract water by different amounts, which accounts for the “rainbow” effect.”

    Well, I’ve covered that it’s TWO effects. I wish to argue strongly that your “growing water droplets” is way off. What were you thinking? You KNOW that the temperatures of the stratosphere don’t rise above freezing point until far above normal aircraft flight altitudes!

    The effect (and its mostly visible on the aircraft exhaust ices due to their relative abundance here) is due to INTERFERENCE – not refraction.

    Due to stratospheric super-saturation, the crystals are progressively growing in size as the agglomerate more ice from the “excess” water vapour.

    As they progressively GROW in thickness (they’re flat hexagonal crystals), they also progressively INTERFERE with specific light frequencies. So you are “bound” to get a rainbow-like effect. Not only that, but subsets of these frequencies will “come around again”, so you’ll get two or three “rainbows”. But as they larger, the crystals get more “exotic” in shape, and degrade this initially “pure” physical phenomenon, until after a quarter of a mile the effect is gone – scattered away.

    At high cruising speeds, the wave vortex of each wing isn’t as pronounced as it is at low speeds and higher angles of attack, but here you CAN see that the tip vortices are “coming inboard” as they follow the aircraft’s wave vortex.

  • The reason I was talking about growing water droplets was mostly to address the low-level aerodynamic contrails, such as those seen in the video. They can form where it is too warm for ice to form.

    Regarding “what I was thinking”, my explanation is partially cribbed from the Gieren poster:

    http://contrailscience.com/files/Gierens_Aerodynamic_poster_060625.pdf

    Which is actually from a paper on the sequence of photos from which this one was taken. In the poster they say:

    The ice crystal size distributions (solid curves) are generated from homogeneous
    freezing of liquid aerosol droplets (dashed). The smallest droplets freeze first,
    followed by freezing of larger droplets, until all available aerosol particles are
    depleted.

    Mie theory was used to calculate optical properties from the size distributions,
    assuming spherical ice particles.

    It then explains this exact color distribution, which matches his assumptions. “Refraction” was probably wrong, I’ve changed the text slightly to reflect “different optical properties”

    The formation of aerodynamic contrails is a very different process to exhaust contrails, it’s not fully understood, but it’s not surpising that the resultant crystals can be very different.

    As for where the photo was taken:

    On June 12 2005 from 14:59 to 15:06 Bejing time (~07:00 UTC) pilot and photographer Jeff Well took a series of 45 photos of an exceptionally colourful iridescent contrail produced by an A340-313X aircraft in 9600 m (31,500 feet) altitude, just 1200 m higher as his position on the same route over eastern China.

    I must admit though, I’m not exactly clear if liquid water can exist at that altitude and temperature, even for the fraction of a second he implies. Deposition (the opposite of sublimation) seems more in keeping with what I’ve read.

  • Haha, so I was right about the photo!

    I read the pdf AFTER I’d posted, and with some trepidation, when I realized the solemnity of the source!

    But I now suspect they also hadn’t properly considered the temperatures involved, and that also the solid ice deposition and accretion would produce by interference the same sequence (in effect) as their results demonstrated – including the scattering they mentioned.

    If exhaust steam at 1100 deg C cools down a 1000 degrees to visibility, hence changing phase to liquid at 100 degrees taking out 540 Kcal/gram in a fraction of a second, I cannot see how it could waste much time at all making a second phase change to solid at 0 degrees taking out only 80 Kcal/gram and dropping a further 30 degrees.

    The strange nature of the ice trail leading from the trailing edge of the wing hold’s one’s attention, doesn’t it?

    It is “backlit” by reflected sunlight off the top of the wing, as well as lit by sunlight from above.

    Quite a show. As ever, your site is superb…

  • I think this paper explains the situation better. Note Figure 1 in this paper is a photo of the same plane taken at around the same time.

    http://contrailscience.com/files/Aerodynamic%20contrails%20Microphysics%20and%20optical%20Properties.pdf

    They estimate the temperature at 241K (-25F), which is rather different to the -40C they mention in the poster. At that temperature, water can exist as liquid supercooled droplets that only freeze when they get to a certain size.

    It does seem to be all explained in the paper. A bit complicated though.

  • Ha!

    You are right about it being “a bit complicated”, but I’m grateful for the complexity. Personally, to fully understand and master THAT would take me about a month of eight-hour days in a technical library. I shan’t be doing it, but thanks.

    It’s interesting that this rare phenomenon will become less rare in the future, as more flights will take place along the Pacific Ring, where warmer and more humid conditions are to be found.

    I like the way they considered the trail in depth and breadth, and made distinctions between particle sizes, and considered simplifications (!) to get their results. Also the discussion of the pre-conditioning of the aerosol particles by previous flights, and their relevance to GW and albedo modification.

    They are right. You are right. A brilliant science paper of 54 pages. I’m off to eat some words…

  • Hello,

    As you quote, “Now, why has NOBODY in the supposed 2 Million “chemtrail” community managed to take a closeup photo of a jet spraying chemicals. Considering you can do it with $700 worth of equipment, it seems rather odd).”

    My thoughts exactly. I believe most of the misconception regarding chemtrails originate over these aerodynamic contrails. From observation, these contrails do indeed last much longer than normal exhaust contrails (most of the time) and are more common in the summer. Furthermore they are usually produced lower in altitude, and as you have shown, there is a level where this aerodynamic contrail can disappear and be replaced with an exhaust contrail. Here are some photos from Flickr photographer Downintheblue: http://flickr.com/photos/downintheblue/563204943/in/set-72157594502002966/
    http://flickr.com/photos/downintheblue/562840736/in/set-72157594502002966/

  • Thanks Ryan, those are some excellent photos!

  • Hi guy

    i’m italian, and i’m from turin

    explaination is a total HOAX because the video, made by a my friend, show a chemtrail.

    this entire site is pure misinformation

  • In Italian.
    Me stesso, se sei così sicuro che sia una scia chimica perché non vai a denunciarlo?
    Ps. anch’io sono di Torino e non credo a quello che dici. Porta delle prove, ma gli sciacOmicari non sono in grado di farlo

    In English.

    Are you sure “Me stesso”? If so you have to denounce it to Italian Police
    P.S. Me too are from Turin (Italy), and I thiink you’re a liar. You’ve to demonstrate it
    Chemtrail are all HOAX, you’re HOAX, not this site

  • Your website is just another disinformation website about the raellly danger of chemtrails.

    You wrote to us that you are just a pilot, but remember a pilot is just a pilot and not a reliable scientist.

    Chemtrails is a real danger here below a list of llustrious scientist, researchers, doctors whom are researching and warning the population about the danger of Chemtrails.

    - Engineer Clifford E. Carnicom, US, New Mexico.
    - Meteorologist Scott Stevens, US.
    - Atmospheric scientist Neil Finley – Canada.
    - Doctor Michael Castle – US.
    - Toxicologist Dr. Hildegarde Staninger – US, Los Angeles.
    - Indipendent jornalist William Thomas – Canada.
    - Research and activist Jerry E. Smith – US, California.
    - Research Tom Montalk – USA.
    - Biologist Dr. Michael Castle – USA.
    - Biologist Dr. Giorgio Pattera – Italy.
    - Director of Nexus Magazin Tom Bosco – Australia.

    This persons are really reliable source of information!!!!!!

  • That’s rather an unfortunate list Sonia. If those are actually the most illustrious scientists who believe in chemtrails, then it does not say much for the quality of the theory.

    You might also want to look at “Project Steve”, for a little perspective.

    http://en.wikipedia.org/wiki/Project_Steve

    But really, one must be careful of relying on ad hominem or appeals to authority – it’s really the facts that we need to focus on. Have the above people published any research in peer reviewed journals?

  • why you are changing topic?
    as i sad you are just a pilot and you cannot write about SCIENCE on contrails and chemtrails!!!!
    the scientists listed above are a reliable source of information of the matter, if you look at their website you will find several articles and scientific pubblication of their research on chemtrails.
    offcourse you dont know them and you did not have even read some scientific document on a serious topic as chemtrails and their danger.

    also why you are covering your really identity? why you are not in the normal register in WHOIS for your domain?
    it is obscure your behaviour and it is clear your aim for this web site.. you just want disinformation on the reality of the danger of chemtrails!!!!

    stop your disinformation without any scientific prove you are just a pilot not a scientists and think about what are you doing!!! you breath as everyone heavy metal!! you must be aware of this

  • Sonia, surely you don’t think people can’t write about science if they are not scientists? I’m interested in flying, and the weather, and science, and pseudoscience – so I write about things that I find interesting.

  • Sonia, if biologists, a couple of vaguely entitled ‘researchers’ and a journalist are reliable sources of ‘chemtrail’ information, then why not a pilot?

    you cannot write about SCIENCE on contrails and chemtrails!!!!

    I’m sure if you browse around the site you’ll find plenty of scientific reasoning as to why there are no chemtrails up there.

  • for Uncinus and James.
    you can write whatever you want on your website. but this does not means ITS TRUE and its true science, as you wrote you are JUST A PILOT interested in pseudoscience so you admit you are not a reliable and objective source of information about the subject.

    as you wrote you are just interested in flying and weather as an amateur, my grand father is interested in weather and flying too but his not opening a website and assumption is a scientists and write about science of chemtrails and contrails… your affirmation are just ridiculous.

    YOU ARE JUST A PILOT, an amateur about flying. your pseudoscience is just you own opinion and ITS NOT TRUE.

    also you seems not be really interested in reliable source of information because for sure you have not read any reliable and scientific documents wrote from illustrious scientists as in the list above provided by me.

    the illustrious scientist listed above are working for important reliable and scientific organization, before speak about a subject you do not know i would invite yourself to read more SCIENTIFIC PUBBLICATION on it.

    also you are not still answering to all the readers of this pseudoscience website…. you do not answer about your really identity, ….

    why you are covering your really identity? why you are not in the normal register in WHOIS for your domain?

    the fact is! you want just disinformation about the real danger of chemtrails and illegal aerosol operations.

    how much do you get payed to write your pseudoscience and disinformation on this website??
    how is really your employer?

    stop your disinformation without any scientific prove you are just a pilot not a scientist and think about what are you doing!!! you breath as everyone heavy metal!! you must be aware of this, you should apologize with your readers for your lack of SCIENTIFIC documentation on your website.

  • Nice work for making this site Uncinus. You put so many contrail related phenomena into one site with good illustrations and easy to understand descriptions. Not like some scientific papers I found on this subject, which give a lot of information , but it’s almost impossible to understand for simple people.

    I am an aviation enthusiast and amateur pilot and have been interested and fascinated by contrails for some time. I live under busy high altitude airway and like to observe aircraft with binoculars and spotting scopes for more than 5 years. I have seen various shapes of contrails, their shadows and it’s really a very fascinating sight.

    For me, as an aviation enthusiast and avid contrail spotter, that chemtrail conspiracy theory looked very funny and very stupid the first time I heard about it.
    But perhaps the sight of huge persistent contrails is so magnificent for some people, that they can’t fully understand it and try to seek alternative explanations.
    Probably like Appollo landing on the moon is also an event above some people’s understanding of human technology limits, so they think it’s a conspiracy. This is just my thought on how some conspiracy theories are born.

  • Sonia-

    The people you listed are not ATMOSPHERIC Scientists…in fact, some are not scientists at all.

    Carnicom is a highly dubious source who has not even acknowledged persistent contrails

    Stevens is a “weatherman” with no backing from his peers…

    Will Thomas?? Please tell me what is scientific expertise is.

    You want science?

    Please enjoy the research papers below- all written by real atmospheric scientists from around the World…all reviewed by their peers…and all acknowledging that normal contrails can and so persist for hour and even days and spread out into a thin haze of cirrus clouds. If they do not think spreading contrails are “chemtrails”….why should you??

    Enjoy!

    http://www.grida.no/climate/ipcc/aviation/038.htm

    http://tinyurl.com/6dphju (note the year- 1986)

    http://tinyurl.com/hvp34

    http://tinyurl.com/4qyaww

    http://tinyurl.com/3lc9ry

    http://tinyurl.com/4spcco

    http://tinyurl.com/3mcj3e

    http://tinyurl.com/3f2y2z

    and this paper from 1970 is quite telling in its description of contrails spreading out and “covering the whole sky”

    http://tinyurl.com/47lcdg

    here is an interesting photo from 1983:

    http://www.1000plus.com/Imagic/8301sund.htm

  • Sonia, sure, I’m “just a pilot”. I wish I was getting paid to write this, but no, I’m simply writing about a subject that interest me. What’s wrong with that?

    No, I’m not a scientist. No, you are not obliged to agree with me. So let’s agree on that.

    Let me ask you a very simple question:

    How long can contrails last?

    Please answer that one simple question, as it’s the most important foundation for any discussion regarding contrails. I’d appreciate it if you could also give references which back up your answer (even references to Carnicom).

    How long can contrails last?

  • [This post has been edited for clarity, ad hominem arguments and duplicate posts have been removed]

    Also the links you listed are an unfortunately list of generic documents about weather took around from some website.
    this list are not related to chemtrails phenomenon.

    I invited you to read some scientific paper wrote by illustrious scient Dr. Hildegarde Staninger – US, Los Angeles. about the danger to chemtrails and linked illness as Morgellons.

  • you cutted and modified my original post!!!!!!!!

    reply to my question (i posted to you 3 times all ready!!!).
    why you are covering your really identity?
    why you are not in the normal register in WHOIS for your domain?
    you are traing to hide your really identity because you want misinform on the true of chetmrails, off course you are payed by someone who is interesting in misinform people about th really danger of chemtrails.

  • Okay, one time:

    I post anonymously (and have a private domain) for personal privacy reasons. That’s my own choice. That’s all.

  • Sonia-

    how long do contrails last?

  • Utterly gorgeous! I get to see a fair amount of contrails where I am as I am right in between a major domestic route and far enough in between that they can get some serious altitude going over. I have seen several types, the ones that pretty much vanish right away, others that seem more like the usual “sky writer” where it does vanish within a few minutes, and the ones that seem to still be streaked across the sky an hour or so later.

    I guess I could be being targeted by those evil government types – but somehow I don’t think the Australian Government is in the same league as the American one for ‘major conspiracies’, lol. Least of all doing it on a major domestic route – of which in Aus are extremely defined and and don’t overlap at all. That would be why all my contrails are always north south.

    That said, with it coming into summer now I am very much hoping I get to see something this beautiful.

  • Dear sonia,

    If you were breathing nearly as much heavy metal as you think you are, you’d probably be very sick or dead, but luckily such things are detectable by doctors. If you’re so concerned then you should probably get a screening.

    Unfortunately, most chemtrail fanatics dabble in pseudoscience such as orgone, over unity, and the like. Just because somebody with a graduate degree says something doesn’t mean it is true or that they are reliable. My statistics teacher has a masters in statistics, or so he claims. He’s an idiot.

    Uncinus however, is doing us quite a service by providing all this evidence from REAL science.

    Great website, btw. Do you happen to have any articles on Crow instability?

  • My attempt at replicating the photo above. This was taken with a Canon 20d with 70-200 2.8L Zoom with a 2x extender. Taken at about 4pm EST.

    http://i34.photobucket.com/albums/d106/jculpjr/contrails-1.jpg

  • Nice photo Jim. If you have the original uncropped image, then you could work out the height of the plane based on its wingspan, and the other parameters. See:

    http://contrailscience.com/measuring-the-height-of-contrails/

  • Dr. Gregory Benford, UC Irvine who works with DOE on weather research says in Toxic Skies, ” You’ve got to in a sense engineer
    all these so you get the right kind of clouds for the effects we want” Paul Moyers paraphrases Dr. Benford and states that Benford says that ” we will probably see it in the near future” -it refering to chemical laden contrails.
    http://www.youtube.com/watch?v=JNDMJCTFslw

    So, we should definitely keep looking up and probing this issue. In the Discovery series on Chemtrails where commercial jetfuel was tested (showing no statistically significant level of aluminum -there was some ) they reported that the Air Force denied a request for a sample of their jetfuel for testing.

    Programs done by the military are often conducted without public knowledge. Every possible indicator is exactly as Benford states with one caveat, Benford says it hasn’t been done yet. There is quite a bit of evidence suggesting that this atmospheric ‘testing’ has been ongoing for decades and it is an evolution that brings this testing well beyond “chaff”

    The discovery channel special shows chaff for creating a radar cover. I suspect that there are more efficient means of dispensing chaff through the use of additives to jetfuel which create the same type of cover. It’s a ‘pet theory’ but one that many dozens of military and atmospheric papers lend support for. Patents which in some cases have been developed into point of use are in evidence.

    Keep looking up and Cheers !
    -Bryan

  • re; above post meant to state that the USAF refused to give a sample of their jetfuel.

    … I’ll let youall decide why they refused…. speculation is so veryyyyyyy unsatisfying isn’t it?

  • Bryan:

    The discovery channel special shows chaff for creating a radar cover. I suspect that there are more efficient means of dispensing chaff through the use of additives to jetfuel which create the same type of cover. It’s a ‘pet theory’ but one that many dozens of military and atmospheric papers lend support for. Patents which in some cases have been developed into point of use are in evidence.

    Most “objections” to contrails are borne of scientific ignorance. This one, your theory, is a classic case in point.

    Chaff works by re-radiating (reflecting) the specific radar beam wavelength because the LENGTH of each conducting fibre is AN EXACT MATCH for the frequency of the radar beam. “Point sources” of aluminum (which is exactly what you’re theorizing here) would be TRANSPARENT to the beam and thus USELESS.

    And then your second point (unbelievable!) is a complaint that the military never let you know what they are doing – they conceal their movements, don’t tell you what fuels they use, you can’t find them on flight logging software. Well, of course they should. That way, you and any enemy will know what they are doing, and your country’s defence would be rendered USELESS.

    Fortunately, their chaff has a tuned length, and they don’t let you know what they’re all doing, so we are all SAFE. (Or at least SAFER!)

  • Chaff works by re-radiating (reflecting) the specific radar beam wavelength because the LENGTH of each conducting fibre is AN EXACT MATCH for the frequency of the radar beam. “Point sources” of aluminum (which is exactly what you’re theorizing here) would be TRANSPARENT to the beam and thus USELESS.

    This patent discusses the various size of chaff, including some “microsphere” chaff. However these are pre-manufactured, and certainly would not work as fuel additives.

    They mention “smoke chaff”:

    Similarly, at optical frequencies, the particle size would be so small at resonance that one would have essentially smoke chaff.

    Optical frequencies are, of course, visible light. Smoke chaff is just a smoke screen.

  • Yes Jazzsymphony, nano sized metals would not work the same as chaff. I am a lot less confident than you that there aren’t ways to employ nanoparticulates for defense purposes. Have you looked at the research papers? Have you read the Eastlund patent on barium, or is that just a waste of time for your ‘angle’ on the subject?

    What do you think (Uncinus or Jazzrap) will be employed in order to engineer the types of clouds Benford discusses? Neither of you seem interested in that, how could you NOT be curious? Is it because it doesn’t fit your beliefs? I suspect you both view this as one of the possibilities of geo engineering but Benford seems quite certain that this will happen.

    -Bryan

  • Benford seems quite certain that this will happen.

    http://www.gregorybenford.com/bio.php

    Benford is also a famous science fiction writer. Not that that disqualifies him from having an opinion, but perhaps his ideas are a bit more wide ranging and far thinking than the average scientist.

    He seems certain that humans will have to modify the climate deliberately. He suggested (in 1997) several ways we might do this. One of them is increasing cloud cover.

    http://www.californiaskywatch.com/documents/htmldocs/benford_climate_controls.htm

  • Brain for Sale:

    What do you think will be employed in order to engineer the types of clouds Benford discusses? Neither of you seem interested in that, how could you NOT be curious? Is it because it doesn’t fit your beliefs? I suspect you both view this as one of the possibilities of geo engineering but Benford seems quite certain that this will happen.

    As you know, Man is already “geoengineering the Earth” willy-nilly and anarchically, in a possibly non-reversible experiment, as he combusts fossil fuels.
    I am all for conscious geo-engineering attempts, but am primarily for those that conscript living processes themselves. These forces have already modified poisonous volcanic emissions into our fresh air, and should merely be encouraged.

    Benford’s article is reasonable. I’m strongly against “engineering the atmosphere” directly (especially using sulfur compounds) and don’t believe there’s the slightest evidence that it’s happening now, either, with barium or aluminum.

    The only “non-living” process I would recommend is Stephen Salter’s Salt-Spray Trimaran, which uses natural salt crystals from evaporated sea water to provide more nucleii for condensation to form, thus increasing cloud cover. This can be carried out in the southern oceans away from human activities, and also reduce the intensity of southern storms. It’s an easily-reversible process, too.

  • Mr. Jeff Well’s photograph appears to be “doctored” a bit too much. In fact, Mr. jazzroc’s comments seem to lend credibility to my following assertions:

    Assertion #1:

    jazzroc said:

    The aircraft is flying high in a partly super-satured stratospheric layer, and the picture wasn’t taken from sea level – because the sky is BLACK. (I can appreciate that a modicum of photographic contrast and colour saturation modification has taken place.)

    I say:
    Why would a modicum of contrast and saturation need to take place? Why not show the actual event as originally photographed, instead of making adjustments?

    Assertion #2:

    jazzroc said:

    The strange nature of the ice trail leading from the trailing edge of the wing hold’s one’s attention, doesn’t it?

    It is “backlit” by reflected sunlight off the top of the wing, as well as lit by sunlight from above.

    Quite a show. As ever, your site is superb…

    I say:
    Proof positive that this is a blatantly “Photo Shopped” picture. If the ice trail is backlit AND lit from the sunlight from above, then why is the bottom of the aircraft fuselage so lit up? And, why are there pinpoints of light on the forward right portion of the red jet engine cowlings? If the sunlight was emanating from above, then certainly there would be no substantial light source from below the aircraft to generate such a photographic effect.

    Thus, the doctored photograph negates any claims that it is in fact real… And lets not get into how a jet, traveling at several hundred mph, can be photographed by a guy, traveling at several hundred mph, in another jet — 1200 meters below — can attain such a pristine looking photograph… Think, “turbulence”, “camera shake”, “light diffusion”, “statistical probability”…

  • John, this is just one of 45 photos in a set of the same incident. Did you not read the linked PDF that shows another 13 of them? This is just the best one.

  • John,

    the underside of the plane is brilliantly backlit by the EARTH (or more accurately the sunlit cloud beneath). Pinpoints of light would be reflections of light from the camera plane. Only if the Earth were MATT BLACK would the underside of that plane be in silhouette.

    (A fine example of “blatant photoshopping” is a “chemtrailer’s” trail “gap”, or “hazmat inside” faked by sciechimiche inside a Boeing 777LR prototype, both which you can find on my site. THOSE are “photoshopping”!

    It appears you have difficulty understanding or interpreting physical realities.

    In the stratosphere there is NO TURBULENCE. The stratosphere gets warmer within increasing altitude and has a serene stability. It’s the reason why passenger planes fly there…

    The camera plane is also a jet. It is smooth – there is NO VIBRATION. The subject is BRIGHTLY LIT from both above and below, meaning that shutter speed would be fast, which also reduces any likelihood of camera shake.

    “Light diffusion” – the atmosphere is clear…

    “Statistical probability” – you’ve lost me there… probability of what? Taking the picture?

    You should get out more often, perhaps buy a camera, go for a flight in the stratosphere (instead of through your fantasies), read a library book on the nature of the stratosphere…

  • Hello jazzroc,

    There you go again… assuming without observing. What sunlit cloud from beneath? I don’t see one. Your “scientific” assertions border on the hilarious. Let’s see, I have read such statements from you, as: “the plane is flying on autopilot….” and my favorite (when talking about a jet flying in a holding pattern): “the pilot probably over-cooked it”. I showed that comment to my relative, who is a pilot, and he just laughed…. yea, overcooked what? the shrimp on the barby?

    [Pinpoints of light would be reflections from the camera plane]. You mean the camera plane that is 1,200 meters below? Sorry, but the angle of reflection does not equal the angle of incidence. The pinpoints of light on the engine cowlings are at a different angle than the photographic camera angle (POV) of the camera plane.

    [No turbulence in the stratosphere]. Just two words for that: Jet Stream…. ["The subject is BRIGHTLY LIT... meaning that the shutter speed would be fast"]. That statement is circular reasoning (something that scientists are famous for). Let me try one: “The football game is on TV… meaning that there would be beer in the fridge.” Yea, that sounds pretty logical to me.

    Oh, I just thought of something: IF the stratosphere is so serene, then why do passenger planes experience great turbulence when flying through a storm? And before you answer that, let me remind you that “anvil” storm clouds can reach an altitude of 50,000 feet — well within the stratospheric layer.

    [“Light diffusion” - the atmosphere is clear…] Don’t you mean “stratosphere”? Gotta’ get your terminology right, you know! Think: The jet is flying at ~ 33,000 feet. Plus, since it is not part of “space”, the stratosphere — and the atmosphere — contain particulates that “diffuse” light… Think of the fake Soviet Space walk and the sunlight on the cosmonaught’s helmet face shield. C’mon jazzy, you gotta’ know that! That is 8th grade science, my man!

    [“Statistical probability” - you’ve lost me there… probability of what? Taking the picture?] Was it just dumb luck the photographer just happened to stumble upon this event, and was able to grab his camera and take the picture?

    [You should get out more often, perhaps buy a camera,]… I’m out every day… and I have seven (7) cameras — both still and video cameras. Now, speaking of cameras, you never did answer my questions about what type of equipment Mr. Jeff Well used to attain such a pristine picture. I anxiously await your answer!

    [read a library book on the nature of the stratosphere…] Well, Mr. jazzroc, I would say that I am more well-read than you.

  • Hello Mr. Unicus,

    Yes, I have seen and read the .pdf file of which you speak of. I have studied the 13 photographs and have wondered why the photos on the .pdf file show the “subject” plane flying from page left to page right… while the photo at the top of this page shows the “subject” plane flying from page right to page left. When did the turnaround happen?

    Also, the plane below seems to not only be 1,200 meters below, it seems to be quite a distance behind. When did the plane below catch up to the “subject” plane?

    And just one more observation” the underside of the “subject” plane in the .pdf file is in no way as “BRIGHTLY LIT” (as Mr. jazzroc says) as the photo at the top of this web page. Why is that? A modicum of luminance and chrominance embellishment, maybe?

    I await your response…

    John

  • The image was probably rotated to fit on the pdf. Possibly rotated for composition on airliners.net. Probably contrast enhanced as well. But, er, so what? It’s still a wonderful photo.

    Jeff Wells says:

    G-VBLU (cn 723) Look! I have dreamt for months to spot this gorgeous scene that a Virgin Airbus with a rainbow contrail. Photo was taking while decsending from 9000m to 8100m when she was climbing to 9600m on opposite direction & nearing route point PIMOL. Many thanks to A.net Photographer Zhangzongli for his help.

    So the planes were traveling in opposite directions.

    The underside of the plane is lit in exactly the same way that the underside of ALL planes are lit.

    I don’t even understand why you think this would have been faked. What about the other photos above, taken from the ground, that show a similar trail, but less distinct, and with a blue background. Are those faked too?

  • John,

    your act should run well in music hall…

    Meanwhile, IF Mr. Well HAD run into a thunderstorm at 28,800 feet, I dare say he would have DROPPED his camera. Needless to say (except in YOUR case) such events normally take place in the tropics, and not where Mr. Well took his photograph.

    There are NO “pinpoints” of light on the subject plane. They are masked by the wider reflections of the bright light from the cloudbase below, which you so hilariously deny.

    When it comes to jet streams, if you learn to study even harder you will discover that the norm for the stratosphere is stable and slow-moving layers, and the rarity is the jet stream (with speeds greater than 80 mph). Perhaps you are hoping to learn atmospheric science by continual argument with me or Uncinus – but this will not be the case.

    And let me point out that his name is UNCINUS, not UNICUS. The very fact that you seem unable to get things correct is what Uncinus and I are interested in.

    Why can’t you do this? What is it, other than your obvious failure to appreciate reality, that you suffer from?

  • Hello Uncinus,

    Let me first address your post before moving on to jazzroc’s…. I will be taking into consideration photos #1, #3 and #4 at the top of this web page.

    YOU SAID:
    “The image was probably rotated to fit on the pdf. Possibly rotated for composition on airliners.net. Probably contrast enhanced as well. But, er, so what? It’s still a wonderful photo.”

    I SAY:
    Okay, I’ll give you the “rotation” and “composition” excuse… but the “contrast” excuse starts to push it. Why make any adjustment at all from the original .pdf file? Why not leave it the same? I can accept the photos on the .pdf file as “original”, but Mr. Jeff Well’s photo at the top of this web page is too perfect. Hey, I can even accept photos 3 & 4 (above) as “originals”, as they beautifully depict the reality of a “real” jetliner flying through a “real” sky… but remember: the argument I have is for the validity of Mr. Jeff Well’s photograph at the top of this web page. It is far too perfect.

    YOU SAID:
    “The underside of the plane is lit in exactly the same way that the underside of ALL planes are lit.”

    I SAY:
    Well then, look closely at all three pictures. Are the undersides of planes #3 & #4 lit “exactly the same way”? Why are not “ALL” these planes lit the same on the underside?

    YOU SAID:
    I don’t even understand why you think this would have been faked. What about the other photos above, taken from the ground, that show a similar trail, but less distinct, and with a blue background. Are those faked too?

    I SAY:
    Refer to my comments above for clarification…. Now, on to jazzroc…

  • Why make any adjustment at all from the original .pdf file? Why not leave it the same? I can accept the photos on the .pdf file as “original”, but Mr. Jeff Well’s photo at the top of this web page is too perfect.

    Because it was a photo submitted to airliners.net, a site dedicated to good looking photos of planes. Nearly all the photos on that site have been enhanced in some way – cropped, sharpened, color adjusted. This is common practice for digital photographers.

    Are the undersides of planes #3 & #4 lit “exactly the same way”? Why are not “ALL” these planes lit the same on the underside?

    The differences can be attributed to photo #3 being taken from the ground, hence the intervening air makes the plane much more hazy (photo #1 was taken from very close to the subject), and photo #4 being taken also from the ground, but also at a different time of day, when the sun is low enough in the sky to directly light the side of the plane.

    However, the MANNER of their lighting is essentially the same – it’s from light reflected from the air, the clouds, and the ground below the plane.

    Think about this: if the only source of light is the sun, then why are the bottoms of these planes not totally dark?

  • [Pinpoints of light would be reflections from the camera plane]. You mean the camera plane that is 1,200 meters below? Sorry, but the angle of reflection does not equal the angle of incidence. The pinpoints of light on the engine cowlings are at a different angle than the photographic camera angle (POV) of the camera plane.

    By “pinpoints of light”, are you perhaps mistaking the painted white markings on the underside of the engines for reflections? Here’s another photo of the same type of Virgin Airbus:

    http://commons.wikimedia.org/wiki/File:Virgin.atlantic.a340-600.g-vyou.arp.jpg

  • That’s another great picture, Uncinus. Well done, there!

  • For Post #45:

    Nice one Uncinus! I’ll give you that: “well done”. I must concede here, that that was a good observation.

  • Hello JazzRoc,

    YOU SAID:
    “your act should run well in music hall…”

    I SAY:
    Thanks jazz… I, like you, am a musician. I’ll take that as a compliment (even though it is a bit backhanded… gotta’ keep a sense of humor, you know)

    YOU SAID:
    “Meanwhile, IF Mr. Well HAD run into a thunderstorm at 28,800 feet, I dare say he would have DROPPED his camera. Needless to say (except in YOUR case) such events normally take place in the tropics, and not where Mr. Well took his photograph.”

    I SAY:
    I did not say Mr. Well ran into a thunderstorm where he was flying. I said that the anvil clouds of thunderstorms can reach an altitude of ~50,000 feet: well within the stratospheric layer. The point I was making, was that the stratosphere is not as “serene” as you say it is. Please re-read what I said in the post (above). Also, thunderstorms happen quite frequently in the desert – quite a beautiful sight when looking east towards the desert from the Los Angeles basin.

    YOU SAID:
    “the underside of the plane is brilliantly backlit by the EARTH (or more accurately the sunlit cloud beneath).”

    I SAY:
    Read what you just said: “the underside of the plane is brilliantly backlit…” Do you know what “backlit” means? Your statement is contradictory.

    YOU SAID:
    “Pinpoints of light would be reflections of light from the camera plane….”
    AND
    “There are NO “pinpoints” of light on the subject plane.”

    I SAY:
    Well, which is it? Are there “pinpoints of light”, or not? Another contradiction, my good man… Bully!

    YOU SAID:
    “When it comes to jet streams, if you learn to study even harder you will discover that the norm for the stratosphere is stable and slow-moving layers, and the rarity is the jet stream (with speeds greater than 80 mph). Perhaps you are hoping to learn atmospheric science by continual argument with me or Uncinus – but this will not be the case.”

    I SAY:
    Repeat after me… slowly: “Tropical Jet Stream… Polar Jet Stream….” Say that three times, and then refer to the following web page: http://en.wikipedia.org/wiki/File:Jetstreamconfig.jpg
    And would you look at that: it is from your favorite source of information – WIKI!!!

    And here’s a little more info. about the “rarity” of Jet Streams:
    Between 1979 and 2001, it has been found that the position of the jet stream has been moving northward at a rate of 2.01 kilometres (1.25 mi) per year across the Northern Hemisphere. Across North America, this type of change could lead to drier conditions across the southern tier of the United States and more frequent and more intense tropical cyclones in the tropics. A similar slow poleward drift was found when studying the Southern Hemisphere jet stream over the same time frame.[49]
    ^ Associated Press. Jet stream found to be permanently drifting north. Retrieved on 2008-05-08.

    YOU SAID:
    “And let me point out that his name is UNCINUS, not UNICUS. The very fact that you seem unable to get things correct is what Uncinus and I are interested in.”

    I SAY:
    Mono-expletive…. Uni-Cus…. UNCINUS… big deal! It was a late night typo. Lighten up and go play some jazz…. or rock, Mr. Jizzsock. Oops! typo again ;-)

    YOU SAID:
    “Why can’t you do this? What is it, other than your obvious failure to appreciate reality, that you suffer from?”

    I SAY:
    “Question authority…” You say you are a scientist… I question it.

  • John Aytche:

    “Question authority…” You say you are a scientist… I question it.”

    Well, you may -one day.

    But being able to comprehend a color picture seems difficult for you.

    What was it you said it was? – “Proof positive that this is a blatantly “Photo Shopped” picture.”

    Which was to do with this:

    http://contrailscience.com/files/Aerodynamic%20contrails%20Microphysics%20and%20optical%20Properties.pdf

    When you’ve plowed through this we could talk some “science”, perhaps.

  • I live in an area that has a rainy season and a dry season. We are right now in the very hottest and driest month of the year, and yet there are still many contrails almost everyday. Why is that?
    I also wonder, shouldn’t global warming lessen the number of contrails we see? Why do we keep seeing more and more?

  • Where abouts do you live?

    It’s not the weather at ground level that’s a factor. It’s the weather at the altitude that the contrails form at. What’s the weather like at 34,000 feet? In, say, Boston, MA, at ground level it’s 55F with 13MPH winds, but at 34,000 feet it’s -54F, with 52MPH winds.

    http://www.usairnet.com/cgi-bin/Winds/Aloft.cgi?location=BOS&Submit=Get+Forecast&hour=06&course=azimuth

    Global warming would actually create slightly MORE contrails, in theory. The height at which they form would rise slightly, but the increased temperature would evaporate more water, leading to higher humidity. There’s a lot of factors though.

  • You don’t need planes to see an aerodynamic contrail. Just look at a Formula1 car when it’s driving at 200mph through humid weather at the Brazilian Grand Prix, or any of the numerous hot and humid races they run. As the “wings” at the front and back create downforce, they deflect the air at a sharp angle and condense the moisture from the air. But without freezing temperatures to convert the water vapor to ice crystals, they also disappear in a fraction of a second.

  • But without freezing temperatures to convert the water vapor to ice crystals, they also disappear in a fraction of a second.

    … unless the RH is high enough that the air is ice-supersaturated.

  • I am perpetually intrigued by aviation and aerospace operations. Very interesting collection of contrails images….these are works of art.

  • Chemtrails appear at all altitudes and all temperatures and humidity levels. At 26,000ft+ in temperatures of -40C where contrail formation is optimal they last about a minute. Watch the documentary “Don’t talk about the weather”, then decide. It’s on YouTube. Features hundreds of chemtrail vs. contrail videos comparing the two in the same sky and also chemtrails starting and stopping, laid in patterns like parallel lines and grids, shapes likes Xs, As and Zs. I highly doubt this comment will remain live.

  • TrutherD, of course your comment will remain! It’s precisely the type of ignorance that those of us who understand the facts like to see! With that comment, you have just said “I know nothing about the atmosphere or aviation and I also accept youtube videos, made by OTHER ignorant people as “fact”, simply because I’m too lazy to research this from the perspective of peer reviewed scientific fact”. Thanks! That video is nothing but paranoid trash made by someone else who is clueless about the truth.

  • If you examine the absorption spectra of water you will find it takes about 10m of water to stop visible light (i.e. sunlight) but only 10 millionths of a meter to stop far infrared (i.e. heat radiated from the earth) – Thats why water appears clear to our eyes but water containing samples need to be made very thin for IR spectrometry.

    So in far infrared light the contrails may well be much larger than they look to us.

    The heat collected may well melt the ice crystals and then the heated droplets could re-radiate the heat out in all directions.. some of which returns to earth enhancing global warming.

    The epa report on contrails shows the visible contrail cover in some areas is 2-3%. I think its unlikely we can change anything about the planet by this much and then expect no reprecussions.

  • Andy: in far infrared light the contrails may well be much larger than they look to us
    I’m not sure about that. They are mostly made of ice frozen much colder than freezing point. There will be a touch of supercooled water too. If there’s no ice there, there will be no trail there either

    The heat collected may well melt the ice crystals
    They must remain in the same state at that altitude in that stratospheric layer. Any temperature rise will instantly accelerate (and warm) the next impinging air molecules.

    the heated droplets could re-radiate the heat out in all directions.. some of which returns to earth enhancing global warming
    They won’t be droplets. The ice crystals will reflect back infra-red downwards, “blanketing” the Earth during darkness. But they also reflect back sunlight (raising the albedo) during daylight. The net result is moot.

    The epa report on contrails shows the visible contrail cover in some areas is 2-3%. I think its unlikely we can change anything about the planet by this much and then expect no repercussions
    That is 2-3% where there actually IS a contrail. It is not 2-3% of the Earth’s surface as a whole. You must remember the surface area of the US amounts to only 2% of the surface area of the Earth.

    Tell you what – why don’t you read the “Contrails-to-Cirrus” link above left on this page and see whether you agree or not? It seems to be well covered there…

  • The presence or absence of the rainbow colors in the contrail is a result of the angle formed between the viewer, plane and the incident light. The presence of a rainbow is dictated by the way light refracts off of circular water droplets. Most sky rainbows are seen when the sun is low and at your back. In the images above I’d guess that the sun had to be very low in the sky to see a rainbow from directly below the aircraft. Someone call the photographer and very for me?

    If you can handle a little physics check out the MIT lecture at http://video.google.com/videoplay?docid=-2978729867097229598&ei=Ddl1S83zH5PorAKF9PjdBw&q=mit+rainbows&hl=en&view=3#

  • Quite right, I missed the paper. Mie scattering is new to me. That better explains the repeating bands of color. I always find it interesting how light interacts with virtually the same medium of water in such a myriad of ways. Scattering, refraction, diffraction in so many different flavors. Sometimes it’s hard to imagine how something as simple as the size of the water droplets can make such a big difference in how the light patterns are interpreted by science. Make them really small and you can’t call it a rainbow anymore. I guess that means the article title is wrong.

  • I guess so :) But I was just using the term “rainbow” in the sense of the spectrum of colors, not the mechanism of creation.

  • Hi again.

    I wanted to make a remark about the explanation you used regarding the different colors in relation to the different sizes of ice particles in the above example of aerodynamic contrails.

    The scientific term is refraction, or the bending of light to or away from ‘line normal’ which is the normal path the light is traveling in. The higher energy the ray (or particle, in this case photons of light) the more it will bend in reference to the observer when it enters a medium of greater refractive index from a lower one (I.E from air into water or glass). This is why if you stick a pencil in a glass of water it appears ‘broken’ if you look at it edge on; the light is being bent or refracted as it travels from the air into the water.

    As for the contrails the same principle that causes the rainbow effect in the different sized ice particles is true of opals: Opals actually do not have a regular repeating crystalline structure like other gems. They’re composed of tiny ‘beads’ or smooth grains of silicates at varying sizes. The larger the grains the longer the wavelengths they refract because essentially the longer wavelengths cannot ‘fit’ inside the smaller grains. The same effect causes you to loose your wireless signal as you pass under an overpass or through a tunnel. The carrier waves literally cannot fit. And so the smaller ice particles are responsible for colors on the shorter end of the spectrum such as blues and greens and the larger ones are responsible for the ones on the longer end such as reds and oranges.

    Just thought I would comment. I hope this post is not too irrelevant to topic, or that I insulted anyone’s intelligence ( I know some guys are going to be thinking, yeah, jackass, we know! we know! It was in school!) I just thought the science was fascinating.

  • Archaeopterix:

    The scientific term is refraction

    No. “Interference“.

  • this article is BULLSHIT

  • What specifically is bullshit bio?

    And he’ll never be seen again. Or there will be copypasta from conspiracy sites.

  • That’s the problem I have with these people…They are NEVER held accountable for their claims. He disappears after making that ridiculous statement and probably believes he has “won a debate”.

  • Really aerodynamic contrails? Nice fancy out 2 big words together – Aerodynamic and contrails put the 2 together and HWAM instant explanation .. What does that mean that the contrails fly better or theyre built to have less friction while moving at a fast pace? – you guys suck

    Binary and trinary weapons read up on that for awhile- for all of you who think the government so convincingly ‘has your back’

  • All right… what you YOU call them?

    I know you won’t be back to read this though.

  • Primo les appareils qui laissent des trainées de consdensation de toute la carling finissent par se refroidir ce qui est assez rapide surtout a la vitesse sub-sonic pour les incultes il est facile de confondre un épandage et un contrail; les chemtrails existent et c est même un programme!! mais cela prouve une chose ils ont peur!!! un coup pour rien avec ce site!!

  • “Interference, not refraction”.
    What a beautiful picture from Jeff Well !!

    I thought I’d add that the phenomenon is the employed in the anodising of aluminium – The colour is produced by creating different thicknesses of oxide layer, apparently.
    It is also used in coatings for lenses, especially laser optics. Different wavelengths of light (ie colours) can be split and/or combined by using optics coated to cause selective destructive interference. See “dichroic filters and dichroic mirrors”.

    Great site, by the way.

    Paul..
    The RoadRunner..

  • Alain Laurendeau (pidgin):

    Firstly the apparatuses which leave trainées of consdensation of all carling end up getting colder what is rather quick especially has the sub-sonic speed for the not cultivated it is easy to merge a épandage and a contrail; chemtrails exists and c a program is even!! but it proves a thing they are afraid!!! a blow for nothing with this site!!

    Another “expert”. Gee, thanks… :(

  • Another hay nonny mouse wrote:

    “Binary and trinary weapons read up on that for awhile- for all of you who think the government so convincingly ‘has your back’”

    Um….known about them for decades…..they have been around since at least WW2 when there was an idea to construct a binary bomb containing magnesiuam arsenise and sulphuric acid – the 2 would mix when the bomb struck, creating Arsine – however it does not appear to have ever been built let alone used.

    Of course the main reason for binary agents is..drum roll…..SAFETY! If one of them leaks you do not have a lethal chemical, asopposed to a leak of a unitary agent in which case you do. The 2 parts can be stored in widely different locations, minimising the chances they will ever get together before they are loaded into a munition. Production for each component is also safer than the lethal derivative.

    Other reasons include improved shelf life (the seperate components often do not degrade whereas the mixed product does)

  • I think you forgot to add “nwo” to your Google search there Mike. The theory there goes that H1N1 and SARS, spread by chemtrails, are part of a widely separated binary (or trinary) weapon. The activating component of which will come in the future and kill all but 500,000,000 people.

    And of course there is less than zero evidence to support this theory. It’s not even that popular on infowars, which says something.

  • Oh right – sorry – I bow to your superior knowledge of fantasies! ;)

  • Nice site, here is a video from 1944 showing contrails, note you can see them “switching” on and off

    So much for the 1997 business

    http://www.youtube.com/watch?v=wfOrez6q7WM

  • Giorgis,
    Very nice indeed.

  • Uhm, you wouldn’t think Uncinus had missed that one ?

    http://contrailscience.com/memphis-belle-wwii-bomber-contrails-1944/

  • Epoxynous is Uncinus’ youtube name.

  • Recently I saw a short rainbow contrail in about the same spot of the sky where there was a sundog just a few minutes before. As it cleared the spot, it became white again. My first thought was that the contrail had produced another sundog, similar to those I had seen previously on some persistent contrails.

    It lasted just a few seconds. Unfortunately, I wasn’t prepared and missed the opportunity to take a picture. I’ve been looking for another opportunity since, but so far unsuccessfully. On the web I found many nice pictures of the contrail-produced sundogs, for example, http://www.dewbow.co.uk/haloes/sundog49.html , but none of them on a new short contrail.

    I’m in doubt now, whether it was indeed a sundog, or I saw a rather different phenomenon. Has anybody here seen a sundog on a short-lived contrail before?

  • Not that I recall, but it initially sounds quite plausible. If there was a sundog there before then that means there was a cloud there that moved. Then the contrail came along.

    However, according to atoptics, the conditions are quite specific, requiring horizontal hexagonal crystals

    http://www.atoptics.co.uk/halo/dogfm.htm

    And it would seem that in a short contrail, the conditions might still be too turbulent for the crystals to be aligned like that. Possibly though it was one of the other ice halos?

  • “And it would seem that in a short contrail, the conditions might still be too turbulent for the crystals to be aligned like that. Possibly though it was one of the other ice halos?”

    Yes, I’ve read this afterwards, hence my doubts that it was a sundog.

  • Clearly though contrails DO create sundogs. So if they require relatively stable, the question would be how quickly the contrail region becomes stable enough.

    The wake vortices persist for several minutes, but they also sink, but then contrails sink. If you look at the video of a plane leaving contrails, clearly they spiral at the start:

    http://www.youtube.com/watch?v=xl6iR7w7a_Q&hd=1

    But further back they are not spiraling. Are they no longer coincident with the wake vortices?

  • “…the question would be how quickly the contrail region becomes stable enough.”

    Good, at least some of my recorded observations may be of help here. I took a series of pictures the last Sunday. The plane flew just below a sundog, leaving a persistent contrail:

    [img]http://contrailscience.com/wp-content/uploads/P1030095.JPG[/img]

    The sun was going down, whereas the contrail was rising up in the sky, so in about six minutes the contrail was above the sundog:

    [img]http://contrailscience.com/wp-content/uploads/P1030104.JPG[/img]

    While passing through the sundog spot, the contrail did acquire some hues, but they were not as brights as on the flanking clouds:

    [img]http://contrailscience.com/wp-content/uploads/P1030101.JPG[/img]

    In the last photo, the contrail is about four and half minutes old.

  • Hi, I thought this was a beautiful example of aerodynamic contrails.
    http://www.airliners.net/photo/Switzerland—Air/McDonnell-Douglas-F-A-18C/1131524/M/

  • UNCINUS:
    “However, according to atoptics, the conditions are quite specific, requiring horizontal hexagonal crystals
    http://www.atoptics.co.uk/halo/dogfm.htm
    And it would seem that in a short contrail, the conditions might still be too turbulent for the crystals to be aligned like that. Possibly though it was one of the other ice halos?”
    [img]http://contrailscience.com/wp-content/uploads/atoptics.JPG[/img]
    Stability of any sort isn’t necessary or possible.
    Hexagonal prismatic ice crystals have weight and are always tumbling when they fall.
    At any one moment in time a PROPORTION of them will be aligned to produce the geometry for the sundog.
    At a next instant there will be the same proportion, but it will be composed of DIFFERENT crystals in the SAME position. Different prismatic crystals shapes and light pathways through these shapes produce the various and complex sundog elements.
    The effect is continuous, just as the effect in a RAINBOW is continuous, even though different drops are involved from moment to moment. Just like going to the cinema, where you watch a continuous film made from 25 frames/sec…
    Some people never get this.

  • No, that’s for a halo. The sun dog requires a majority of the crystals to be aligned, so in needs flat hexagonal crystals. So would not show up in highly turbulent air.

    What you might see is a portion of a halo, but not a sun dog, which is much brighter.

  • As I understand it, haloes and sundogs are part of the same family. You see a halo when the sun is high and dogs and various arcs when it is low.

    I don’t think the contrail or that flatish cumulus is contributing anything to the sundog that is occupying the same part of that photo.

  • They do rely on different types of crystals though. You see sun-dogs when the sun is low because the flat plate hexagons are horizontal, and you need to see them edge on. They would still contribute to a regular halo in other positions regardless of orientation as well as it’s just the same 22 degrees. The flat plates are just like very short hexagonal prisms.

    I don’t think halos are more common when the sun is high – just that when the sun is low, the sun-dog is often the more prominent feature.

  • Yes, you are correct… The flat plates are just like very short hexagonal prisms.

    My main point was that the contrail and that flattish cumulus are not contributing anything to the sundog.

  • Look-up the article on where did the planes go over Los Angeles and you will find out why this guessing at grabbing at straws is not the answer to THE REAL TRUTH that this is happening.

  • Thought you might like a look at some (extremely short) aerodynamic contrails.

    http://www.youtube.com/watch?v=RE9hYLcUnN8

  • I want my blue sky back!!

  • It’s ok, the debunking comminity has arranged for you all to get it back in Summer. Consider it a late Christmas present.

    You’ll find also that you continue to ‘get it back’ yearly, as the Summer conditions in the upper atmosphere become less conducive to the persistence of contrails.

    You’re welcome.

  • That stuff is not supposed to blanket the entire sky and form a thick haze. If I wanted that I’d go live in LA…CMON here. I have not seen one shred of evidence here claiming that ‘chemtrails’ by the contended definition don’t exist! I agree some of the tests done are dubious. But where are your sample tests in the environment and citizens in areas where they seem to form in whatever condition the air is in?? They are supposed to dissipate, not be excessively persistent and hazy!

    Ive heard reports of biological agents, like blood and flu, raining down from the sky in Detroit and a couple other cities in the early 2000′s collecting as a yellowish weblike material. Check that out.

    I appreciate some of the patent notices on the delivery vehicles etc tho. It shows you have some neutrality. We will find out what is really going on eventually, but the BOOK IS STILL OPEN!

  • The people claiming chemtrails to exist need to prove they do. So far they provided the world with a mountain of bunk.

  • Proof lol? To non believers even if the truth hit them in the face they woudn’t believe. Ever heard of Hughes Aircraft Patent #5,003,168? No probably not. Tell me if you feel anything… Again, probably not.

  • @AtleastIKTT

    Do you mean the United States Patent 5003168 (Trigger circuit for a streak camera sweep drive circuit)?
    It has nothing to do with aircraft

  • Search Hughes Aircraft Patent #5,003,168. Dont play dumb. And ill check to make sure its right in case I’m BEING dumb.

  • Im BEING dumb #5,003,186

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