A Very Unusual Contrail

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Okay, it’s not actually a contrail.   But it’s a related phenomenon - a plume of hot humid air is rising from a volcano, and where it hits the cold upper air, the water vapor it contains condenses out.  Possibly into ice, but it’s hard to tell.

The brown clouds are volcanic ash.   The white round cloud is condensed water.

Here’s a wider shot:

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You can see the plume must be very high.  See it has cast a shadow on the cloud layer, which has been pushed away from the volcano by the rising air.

Here’s the original image from NASA

http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS020&roll=E&frame=9048

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Modern Contrail Confusion

This photo is from January 29th 2009, at approximately 3-4PM over Corvallis, Oregon.

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It shows a contrail from a plane that has made a 540 degree turn (one and half full turns) to fly back the way it came.  This photo was probably taken an hour after the plane made the turn, judging by the amount of spread.

This provoked some interest in the local press:

What’s that up in the sky?

Jet trail has mid-valley looking up, imaginations soaring
A misguided passenger airliner?
A military jet on maneuvers?
A visitor from another planet who decided not to stick around?

They even got a quote from a local authority:

But another viewer noted, “I got a shot of this unusual trail also. I’m an aircraft mechanic and that does not seem like a condensation trail to me.”

(Not sure why an aircraft mechanic would be an expert on contrails, but there you go).

The next day, things were resolved:

Contrail could be from Boeing jet
By Steve Lathrop
For the gazette-Times
Test flight tracked as far south as mid-valley

FlightAware.com shows the meandering path of a flight [BOE504 - a Boeing 737-800 test aircraft] from Boeing Field in Seattle that apparently came as far south as the mid-valley Thursday and then returned. The site says the plane departed at 11:40 a.m. and landed at 2:59 p.m. The loop-the-loop contrail was photographed over Albany around 2:30. At its southern tip over the mid-valley, the flight path shown on the site appears to circle in just the shape the contrails were seen.

Several readers sent in photos.

This contrail is very similar to the one I described (and tracked with FlightAware) in Voodoo Contrails, but what’s interesting here is the similarity of the story to stories in “contrail confusion is nothing new“, where, back in the 1950s, people were having the exact same reactions to contrails, and newspapers were writing the same stories:

Back in the 1950s, of course, contrails were less common.  Now it takes a rather unusual contrail to spark the public’s imagination.     However, in some places, contrails are still relativly uncommon, so still get mistaken for UFOs, such as these in Hawaii, 2007:

Ground Level Contrails

Contrails form when the water in engine exhaust mixes with cold moist air and freezes. Normally you see this at 30,000 feet with jet engine exhaust. But in some parts of the world, these conditions can be found at ground level. Here’s a car leaving a contrail in Alaska

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(Photo by Yukon White Light, original here)

Over time these contrails can spread out to form a haze that covers the area.

Ice Fog and winter driving

From a distance this ice fog (Seen here in Fairbanks, Alaska) can look just a like layer of cloud or mist:

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Here the individual car contrails quickly merge into a single sheet due to their small size and large number.  A jumbo jet obviously creates a much bigger contrail, something more like the building in the middle of the above photo.   That’s why you get the more distinct white lines in the sky.  And of course, at around 30,000 feet, it’s much more likely to be 40 below than it is at ground level - except for Alaska in the winter.

At the South Pole, they regularly have contrails at ground level:

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Life Magazine Contrail Photos

1988 - A vapour trail crosses the sky above the Suleymaniye Mosque and the Yeni Cami or New Mosque in Istanbul

1970 - Vapour trails across the sky

1970 - Vapour trails across a pink sky at sunset

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Cirrus Uncinus and Contrails

 

I took these photos around 8AM this morning, Feb 4th 2009, in Los Angeles.

 

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They show Cirrus Uncinus clouds, with a contrail running through them.

Cirrus uncinus clouds (or “Mares’ Tails”), according to wikipedia:

Cirrus uncinus is a type of cirrus cloud. The name cirrus uncinus is derived from Latin, meaning “curly hooks”. Also known as mares’ tails, these clouds are generally sparse in the sky, and very thin.

The clouds occur at very high altitudes, at a temperature of about minus 40-50 degrees Celsius. They are generally seen when a warm or occluded front is approaching. They are very high in the troposphere, and generally mean that precipitation, usually rain, is approaching.

And indeed, looking at the forcast, rain is coming, predicted for tomorrow and the next three days.

The long “tails” of the cirrus uncinus clouds are actually precipitation - very high snow in the form of tiny ice crystals falling through the air.  The wind blows these sideways, giving the distinctive hook shape.

The contrail in the same region is persisting for the same reason the clouds persist - it’s in a region of the atmosphere where there is moisture.  Notice the abrupt end of both the the contrail and the clouds at the left of the second photo. Contrails are a form of cirrus cloud, and if there is enough moisture in the air, a contrail will eventually spread to be indistingushable from the surrounding cirrus.  In this case though, the cirrus uncinus would have been exactly the same even if there were no contrails.

Twilight Zone Contrails

I was watching the first episode of The Twilight Zone, Where is Everybody, made in 1959, and I noticed that the movie poster had a nice depiction of some persistent contrails forming a grid:

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I don’t think it’s a real poster, but it’s a real movie (Battle Hymn, with Rock Hudson), and a real 1959 episode of the Twilight Zone.  Just goes to show, contrails have been in American popular culture for quite a long time, at least fifty years.

If anyone recognizes the original image, please let me know where it’s from.

And while we are on the subject of posters, check this out:

http://www.flickr.com/photos/49502995517@N01/433032511

Things are not as they seem

This is an actual photo, not photoshopped.  

The stork is not at the same altitude as the contrail, it’s actually quite a bit lower.   It’s the same thing when you see two planes, one making a contrail, and one not - they are just at different altitudes.

Voodoo Contrails over Los Angeles

I was walking along this morning at around 10AM, when I noticed a huge semi circular contrail, somewhere to the south of LAX.  This is something I’ve never seen before.  The weather was very well suited for contrails, and there were quite a few criss-crossing the sky.   

Then about half an hour later I saw another one.   Now it was really interesting.   I hurried home to get my camera, but by the time I was home things had blown east a bit, and I was not able to get a very good shot.

You’ll have to take my word for it - it was very impressive.   I’m hoping that people in the “chemtrail” community will also have seen it and will post some better photos, and I can update this post.

[UPDATE 12/4/08] Here’s One from the Ontario Weather Service, titled “A perfect circle”: 11/20/08 - “A Perfect circle in the morning”, taken by Bettina Gilois, Pacific Palisades, CA:

So what was it?   Well, I went to the FlightAware web site and looked for planes that looked suspicious.   I saw one flying over Catalina, with the call sign VooDoo1, so I looked at that, and bingo:

 

That’s the guy.  The text next to the plane reads:

VOODOO1 B722
291 377
KLAX KLAX

Which means it’s a B722, flying at 29,100 feet, speed 377 knots, and it took off from LAX and is going to land there.   It’s still flying now, about three hours after I first saw it.

What is VOODOO1?  It’s actually a plane owned by Raytheon, N289MT, a test plane that they use to test avionics equipment:

Here’s the satellite photo for the region in the map, showing the high level wispy clouds, and some contrails.

 

The photo was taken around noon, by which time the plane was no longer leaving trails.  It’s quite possible it contributed to some of the haze over the the east.

People Don’t Notice Contrails

I find clouds fascinating.   If I see a lenticular cloud while driving I might nearly crash the car while straining for a better view.   I’ve only seen mammatus clouds once in my life, and stopped to try to take a photo.  I’m quite fascinated by contrails and contrail shadows, especially the “black beam” shadows that seem to extend in front of the contrail.   

Yet my fascination is not shared by the general population.  When I saw the mammatus there was nobody pointing up at the sky.    Other people on the freeway were not swerving their cars, despite the impressive black beam in front of them.   Why not?

Unfortunately, the answer is rather simple: they’re just not that into clouds.  

Yes, my cloud obsession is simply not shared by other people, much in the same way that I don’t understand my friends interests in certain sports, or cars, or the contestents on American Idol.   They might be similarly bemused by my lack of interest in such things.  But the point here is that most people’s interest in clouds is limited to A) is it sunny? and B) might it rain?

So it’s hardly surprising that the gradual increase in contrails over the last 30 years has gone much without comment.   Each year the sky looks pretty much the same as last year.    But then, you get some people who, for some reason, started looking at the sky with more interest, and they noticed, for the first time, that the sky sometimes gets covered by contrails that spread out into a layer of cloud.

They then sometimes slip down a slipperly illogical slope - if they had not noticed this before, then that means it was not there before, hence it just started, and hence again it must be something deliberate.   So the “chemtrail” theory is born - these persistent contrails are actually some kind of nefarious deliberate spraying by the powers that be.

You’ll note that this theory is based on one fact in the theorist’s mind: “I did not notice this before”.

So, if you did not notice something, and hence it did not exist until you noticed it, then what about all those people who have NOT yet noticed that contrails spread?  Do the contrails not spread for them?   

The reality is that the vast majority of people simply don’t pay much attention to clouds, or planes in the sky. The contrails have been there all their lives, and they might as well be noticing the type of covering used on the road outside their house, or what hairstyles the newsreaders have   For most people it’s stuff that is simply there, and does not impact their lives in one way or the other.  It changes slowly over time, but day to day you don’t notice any change.

Sometimes though some people notice things that others have not, and then you can get into an argument about how things are, or were.  One such argument took place in 1971 between celebrity activist Arthur Godfrey and Senator Gordon Allott, R-Colorado,  over possible effects of the then proposed supersonic transport (the SST, a high speed plane like the Concord).   

One of the concerns Godfrey raised about the SST was the possibility of excessive contrail coverage.  The problem of contrails creating clouds was well known in 1971, and Godfrey was well aware of this from personal experience.  But Senator Allott was simply a person who had never noticed these spreading contrails, and hence we get the following newspaper clipping from the March 11, 1971 Missouri Mexico Ledger: (See the 4th story across at the top: “Godfrey calls SST ‘Nonsense’“)

Godfrey tangled with Sen. Gordon Allott, R-Colo., when he said present jetliners are environment hazard enough without adding SSTs to the skies. Godfrey said he’d seen, on hunting trips to the Colorado Rocky Mountains, blue skies ”clouded over” by jet contrails by 9:30 in the morning.

Allott said he’d lived in Colorado all his life without ever seeing jet contrails form clouds—and said he has too much respect for the environment go go on hunting trips and shoot animals.

If a US Senator failed to notice these spreading contails spreading in 1971, is it really that surprising that people still don’t notice them now?  Or that people who believe in “chemtrails” are simple people who have only now, for whatever reason, taken an interest in the skies.

Memphis Belle WWII Bomber Contrails - 1944

This is an excerpt from the 1944 film “The Memphis Belle: A Story of a Flying Fortress”. The full original film is public domain, and can be found here:

http://www.archive.org/details/TheMem…

The film shows contrail formation, including showing “broken” contrails.

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

Make sure you listent to the audio, as it explains how high the planes are, how cold it is, and why contrails form.

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