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Airplanes Cause Accidental Cloud Seeding

timothy posted more than 3 years ago | from the you-think-boeing-and-seattle-is-a-coincidence? dept.

Earth 151

An anonymous reader writes "A new study by a team of U.S. researchers found that commercial and private jetliners may be contributing to a form of accidental cloud seeding. When an airplane flies through a cloud, its propellers cause the expansion and cooling of the air behind them which can cause water droplets to spontaneously cool and crystals to form. The aircraft sets off a chain reaction in the cloud that can continue on for hours after the plane has passed by. The researchers also discovered that this phenomenon is more common near the poles, where many of Earth's weather monitoring systems are, and it could be skewing data that research teams are gathering in those areas."

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"Propellors"? (0)

Anonymous Coward | more than 3 years ago | (#36638636)

Now you're into the time slip...

Re:"Propellors"? (1)

petteyg359 (1847514) | more than 3 years ago | (#36638674)

They're those things that spin around on a motor. They're quite useful, because they behave differently than jet engines in certain conditions.

Re:"Propellors"? (0)

Osgeld (1900440) | more than 3 years ago | (#36638702)

oh we know what they are, but when was the last time you saw a commercial plane with them? let alone a propeller powered commercial jetliner...

this entire thing stinks of stupid

Re:"Propellors"? (1)

petteyg359 (1847514) | more than 3 years ago | (#36638758)

Did you miss that first sentence of the summary where it clearly said " private and commercial"?

Re:"Propellors"? (1)

magarity (164372) | more than 3 years ago | (#36639310)

Did you miss that first sentence of the summary where it clearly said " private and commercial"?

I didn't miss it but apparently you missed the part about 'over the poles'. And they didn't mean poles as in Polish people.
 
The only prop aircraft over the poles is the (very) occasional TU95 Bear bomber.

Re:"Propellors"? (3, Informative)

DougF (1117261) | more than 3 years ago | (#36639838)

Fail. The LC-130H is commonly seen over both the Arctic and Antarctic, and it has 4 props and skis.

Re:"Propellors"? (1)

jimmydevice (699057) | more than 3 years ago | (#36639440)

Did you miss the "commercial and private jetliners" in the first sentence?

Re:"Propellors"? (4, Informative)

Wyatt Earp (1029) | more than 3 years ago | (#36638846)

I saw some yesterday, Dash-8s and there a lot of other propeller commercial aircraft out there.
http://en.wikipedia.org/wiki/Bombardier_Dash_8 [wikipedia.org] - turboprop
http://en.wikipedia.org/wiki/Beech_1900 [wikipedia.org] - turboprop
http://en.wikipedia.org/wiki/Cessna_406 [wikipedia.org] - turboprop

We even have one of these flying out of Anchorage
http://en.wikipedia.org/wiki/Lockheed_L-100_Hercules [wikipedia.org] along with
http://en.wikipedia.org/wiki/DC-3 [wikipedia.org]
http://en.wikipedia.org/wiki/DC-6 [wikipedia.org]
http://en.wikipedia.org/wiki/Short_360 [wikipedia.org]

Re:"Propellors"? (1)

Joce640k (829181) | more than 3 years ago | (#36640228)

Yep, we get loads of commercial props around here. The Dash-8s hold about 40 passengers so they use them on routes where they can't fill Airbuses. I've been on quite a few of them, they fly pretty good and aren't noisy when you're inside them. Only problem is the top speed which is less than a jet.

Re:"Propellors"? (1)

Wyatt Earp (1029) | more than 3 years ago | (#36640328)

I flew on a Dash-8 last summer from Seattle (KSEA) to Portland (KPDX) in the morning, pilot was able to take us right over Mt St. Helen's crater at about 12,000 feet, gorgeous flight.

My cousin flies A320s and whenever I mention Dash-8s his response is "Man, I love those planes."

Re:"Propellors"? (2)

Travelsonic (870859) | more than 3 years ago | (#36638976)

.. but when was the last time you saw a commercial plane with them?

Actually, just before the sun set - a DeHavilland/Bombardier Dash-8 of US Airways Express.

Re:"Propellors"? (1)

Scrameustache (459504) | more than 3 years ago | (#36638978)

last time you saw a commercial plane with them?

Must have been a few days ago, I don't usually bother to look at every plane that goes by, but if I want I'll see a commercial propeller plane go by within the hour, I just have to go out and point my nose up.

Re:"Propellors"? (1)

the linux geek (799780) | more than 3 years ago | (#36638988)

Constantly. US Air especially uses props for short-hop flights.

Re:"Propellors"? (1)

RoFLKOPTr (1294290) | more than 3 years ago | (#36639142)

this entire thing stinks of stupid

You stink of stupid.

Domestic airports in relatively-major cities (relative to their surrounding area... think Bakersfield, Billings, etc) don't usually have big enough runways to support large jets, so they use regional jets and turboprops. The big airlines usually don't run their own small planes. Rather, they use a different banner (United Express, Ted, Delta Connections, etc) for their regional services and usually contract that out to smaller airlines. I used to fly from California to South Dakota for a hunting trip every year, and usually United would put me in a 737 from SFO to Denver, and I'd get in a United Express EMB120 operated by SkyWest. That is one tiny freaking plane. 30 passengers. It's a fun ride as you're descending through the bumpy South Dakotan air.

No, there aren't any 737-sized turboprops, but there are plenty of commercial planes with propellers.

Re:"Propellors"? (1)

starblazer (49187) | more than 3 years ago | (#36639692)

The big airlines usually don't run their own small planes. Rather, they use a different banner (United Express, Ted, Delta Connections, etc) for their regional services and usually contract that out to smaller airlines.

TED was never a small plane airline, it was a "vacation" subsidary of United. It never flew anything smaller than an A320. Now, Anything "Express, Connection" or pretty much most planes from Republic Air Holdings (short of the small fleet of A319s it acquired from Frontier) is RJ.

Re:"Propellors"? (1)

Wyatt Earp (1029) | more than 3 years ago | (#36640074)

Those airports used to support MD-80s, DC-9s, B-727s, B-737s, BAe 146s, but after deregulation and the consolidation of the airlines the planes got smaller and smaller.

From 1980 through 1995 I'd fly in and out of Pierre, Bismarck, Rapid City, Sioux Falls, or Billings out to Eugene, Portland, Spokane or Sacramento.

I've even seen L-1011s and DC-10s in Pierre and Aberdeen way back when.

Re:"Propellors"? (1)

MichaelSmith (789609) | more than 3 years ago | (#36639342)

propeller powered commercial jetliner

Turbo props are used for short distance commercial transport, especially between small airports and where demand is low. They use turbojet engines.

Re:"Propellors"? (1)

rossdee (243626) | more than 3 years ago | (#36639370)

Smaller commercial planes are sometimes turboprop powered. I last flew on one 10 years ago, but I am sure they are still in service on small city to city routes of 300 miles or less.

Re:"Propellors"? (2)

dave420 (699308) | more than 3 years ago | (#36638796)

Ever heard of a Turboprop engine? They're extremely common.

Re:"Propellors"? (1)

Sicily1918 (912141) | more than 3 years ago | (#36638848)

In commercial aircraft? Even private airliners use jet turbines...

Re:"Propellors"? (4, Interesting)

dave420 (699308) | more than 3 years ago | (#36638952)

Yes - in *plenty*. It amazes me that people don't know that. There are a shit-tonne of turboprop aircraft the world over, including the US.

Re:"Propellors"? (1)

antifoidulus (807088) | more than 3 years ago | (#36639708)

Yup and their numbers will probably increase, not decrease at least in the near future because of their fuel efficiency. A turboprop uses considerably less fuel than a jet, esp. for short to medium distances.

Re:"Propellors"? (1)

Adriax (746043) | more than 3 years ago | (#36638962)

Not on my first/last/only flight 5 years ago.
Twin prop engine, only 4 seats wide, out of a small town airport on behalf of Delta. Not everything is a jumbojet out of LAX/Seatac/ect...

Re:"Propellors"? (1)

Deadstick (535032) | more than 3 years ago | (#36639278)

Oh, fer chrissake...google "Beech 1900" or "ATR-72" or "Embraer Bandeirante", among others.

rj

Re:"Propellors"? (1)

MichaelSmith (789609) | more than 3 years ago | (#36639368)

I have never once seen a privately owned turboprop. They are basically workhorses for middle range airlines and commercial operations which need to carry a lot of stuff with short strip capability. Air ambulances for example.

Re:"Propellors"? (1)

capnkr (1153623) | more than 3 years ago | (#36640042)

You don't hang out at general aviation airports or with pilots much, then. See my comment [slashdot.org] below, and if you can at all arrange it, try going to EAA Airventure [airventure.org] in Oshklosh, Wisconsin this August. You will learn. And have LOTS of fun.

Re:"Propellors"? (1)

Wyatt Earp (1029) | more than 3 years ago | (#36640086)

There are quite a few general aviation turboprops, even see them at Merrill Field here in Anchorage.

Saw a Cessna 206 and Pilatus PC-6 without corporate colors June 30 flying

Re:"Propellors"? (1)

capnkr (1153623) | more than 3 years ago | (#36640026)

FYI - a 'turboprop [lmgtfy.com] ' engine is basically a jet engine (or "gas turbine") powering a propeller; the turbine powerplant is more efficient, more mechanically reliable, and has longer TBO's (time between overhaul; 3-5K hours vs 1-2K) than a reciprocating engine. These are just some of the reasons that turboprops are extremely commonly used as working, commercial aircraft, hauling passengers *and* freight, whether employed by large airlines, regionals, freight co's, and/or small independent operators (think bush pilot, air taxi, etc...). Planes like the Cessna Caravan [cessna.com] are common, although I get a hoot out of the ex-DC-3 Basler Turbo-67 [baslerturbo.com] Turboprops are also quite commonly used on high-end civil and business aircraft, like Pilatus [pilatus-aircraft.com] and Piaggio Avanti [piaggioaero.com] .

Re:"Propellors"? (2)

stox (131684) | more than 3 years ago | (#36639656)

Most jet engines, these days, are high bypass turbofan engines. In many respects, not that much different from a Turboprop. The bulk of the thrust comes from the driven element, ie. the fan or prop, rather than the thrust from the turbine itself.

Re:"Propellors"? (1)

MacGyver2210 (1053110) | more than 3 years ago | (#36639490)

A turbine is just a propeller with a hell of a lot more blades...it would logically have the same effect, if not more.

Re:"Propellors"? (1)

mcavic (2007672) | more than 3 years ago | (#36639754)

That was going to be my suggestion.

Not new news (5, Informative)

Afforess (1310263) | more than 3 years ago | (#36638644)

Meteorologists have known about this for some time. They tend to form what is known as "Hole Punch" clouds.

Examples: http://bit.ly/lAxNQO [bit.ly]

Re:Not new news (0)

Anonymous Coward | more than 3 years ago | (#36638708)

Wow. That was actually what it was billed as! No goatse! I'm astonished.

Also known as "contrails" (0)

Geoffrey.landis (926948) | more than 3 years ago | (#36638880)

Meteorologists have known about this for some time.

The common term for it is "contrails."

Yes, it's well known that contrails sometimes to grow into cloud cover. (High altitude thin clouds, not puffy cumulus ones). This is not news.

Re:Also known as "contrails" (2)

sjwt (161428) | more than 3 years ago | (#36639016)

I do believe you did not look at the photos, so from another website, here is some text for you to read.

As a note, because of what ever technical reason stooped you looking a the lint, these clouds can and do look at times look like massive eyes or holes in the clouds, nothing at all like contrails, and in some cases can look like a massive gouge taken out of the clouds, kinda like a revers contrail.

http://www.weatherthings.com/HolePunch.html [weatherthings.com]

"A “Hole Punch” cloud is a non-technical name given to a cloud formed from an aircraft dissipation hole or trail. They are also called "Punch Hole" clouds. Rather than extending as a line, Hole Punch clouds appear as a circular or oval hole in a deck or thin layer of supercooled water clouds. They are not uncommon where jet flight paths intersect altocumulus layers. What is uncommon is when they form in a perfect circle that persists for a length of time to be widely observed."

Not contrails (1)

michelcolman (1208008) | more than 3 years ago | (#36640580)

This is actually not about contrails, but quite the opposite. A contrail is a cloud created by the passage of an airplane (due to the vapor from the engine or simply the dynamic effect of stirring up oversaturated air). This study is about airplanes flying through clouds and causing those clouds to start raining. In a way, they are erasing clouds ("punching holes" in them)

Re:Not new news (1)

MobileTatsu-NJG (946591) | more than 3 years ago | (#36639126)

I can't believe I actually fell for clicking on this... ... good thing it's legit.

Re:Not new news (0)

Anonymous Coward | more than 3 years ago | (#36639606)

Obviously its caused by HAARP and airplanes are being scapegoated.

How is this news (5, Informative)

Anonymous Coward | more than 3 years ago | (#36638646)

I mean seriously, this has been known for decades. There was even a study that looked at the 9-11 shutdown of air-traffic affected climate [cnn.com] .

This has been known for a long time.

Re:How is this news (1)

ChrisCampbell47 (181542) | more than 3 years ago | (#36639104)

Precisely. Someone mod parent up please.

Re:How is this news (1)

MichaelSmith (789609) | more than 3 years ago | (#36639392)

I have only flown across the US once (I am an Australian) but I was surprised to see how many contrails we crossed going from New York to Los Angeles. It may be the distributed nature of the US population. Aircraft go all over the place and cross each others paths with surprising frequency.

Re:How is this news (0)

Anonymous Coward | more than 3 years ago | (#36639252)

Yes - 9/11 ended the experiment of jet travel for 3 days and this is a known result - I remember it being discussed on day 2 of the shutdown.

Re:How is this news (0)

Anonymous Coward | more than 3 years ago | (#36639458)

Check http://radar.weather.gov/Conus/full_loop.php in the evening. You can usually spot westbound radar returns that might be correlated with air traffic.

Re:How is this news (2)

excelsior_gr (969383) | more than 3 years ago | (#36640330)

I agree with what you said, I just want to do some CNN-bashing:
Those damn journalists were trying to be sensational again by saying that the air traffic affects the *climate* while it is obvious that it just affects the *weather*. If the air traffic disappears the *weather* will just roll back to its usual behavior that is dictated by the *climate*. Of course, I am only taking about the condensation wisps that are referred to in the article, not the aircraft emissions, that do have an effect on the *climate*.

But I guess the word weather is out of fashion, and climate sounds so much better... Damned journalists, I hate you guys...

That's the bees knees, Professor! (0, Offtopic)

blair1q (305137) | more than 3 years ago | (#36638656)

Next week when we come by for Slash Dot Mystery Time, can we talk about how steam valves and clock gears work?

That would also be a slide in the ice-house.

And this is nothing compared to.... (-1, Offtopic)

threeseas (2245516) | more than 3 years ago | (#36638662)

...chemtrail. And before anyone gets in a tizzy about the chemtrail topic, weather its real or not.... its not only real but mentioned in weather modification and other paperwork from the US government. This makes the topic of accidental cloud seeding pretty much a non-topic.

Re:And this is nothing compared to.... (2, Insightful)

blair1q (305137) | more than 3 years ago | (#36638762)

Contrails are real. Jet exhaust contains chemicals. Those chemicals are pollutants. They can cause respiratory problems and maybe birth defects. But they can't cause mind control, other than the ability to twist some people into a knot when their brain power meets their ignorance in a paranoid delusion and motivates them to make fools of themselves and enemies of everyone sane.

Re:And this is nothing compared to.... (1)

dominious (1077089) | more than 3 years ago | (#36638778)

weather its real or not.... its not only real but mentioned in weather modification and other paperwork from the US government.

I agree that whether modification its real weather people agree with it or not.

Re:And this is nothing compared to.... (2)

dave420 (699308) | more than 3 years ago | (#36638926)

Chemtrails = bullshit. Abject, horrific bullshit, spread by idiots who don't have a fucking clue about meteorology, basic physics, and more importantly that a few documents mentioning cloud seeding do not instantly mean that even one single witnessed contrail is anything other than a contrail. Critical thinking - it works, bitches.

Re:And this is nothing compared to.... (1)

drinkypoo (153816) | more than 3 years ago | (#36639404)

Abject, horrific bullshit, spread by idiots who don't have a fucking clue about meteorology, basic physics, and more importantly that a few documents mentioning cloud seeding do not instantly mean that even one single witnessed contrail is anything other than a contrail.

Snicker snort. I bet you're attacking the non-arguments from the fringe of the fringe. It's a long jump from reality, where the military continually talks about ongoing plans and goals to "own the weather" with new papers published talking about how it can be done regularly, to "a few documents mentioning cloud seeding". I'm sure you think this is totally normal [hyperlogos.org] for example.

Critical thinking - it works, bitches.

though not for you.

Re:And this is nothing compared to.... (1)

Lehk228 (705449) | more than 3 years ago | (#36639898)

are you seriously supporting chemtrail bullshit?

Re:And this is nothing compared to.... (2)

dave420 (699308) | more than 3 years ago | (#36640426)

Yes, aircraft changing course is totally normal. Heck, large circles are even perfectly normal. Can you provide evidence as to how they are not normal? That's how critical thinking works. Apparently you don't understand that, which is why you believe this bullshit.

arg (1)

Osgeld (1900440) | more than 3 years ago | (#36638676)

Please quit wasting our tax money, seriously the people who did this study should have their funding removed as all they have done is have a "no shit mr 1934" moment over technology that is darn near extinct

Re:arg (1)

MightyMait (787428) | more than 3 years ago | (#36638722)

Don't jet engines have a propeller-like thing called a turbine? Wouldn't they have a similar effect?

Re:arg (0)

Osgeld (1900440) | more than 3 years ago | (#36638730)

Similar as in they are objects that spin, but otherwise no, not really

hell do us a favour and go stand behind a jet engine and let us know how cool the air feels to you

Re:arg (1)

MightyMait (787428) | more than 3 years ago | (#36638900)

Well, exqueeze me!! How about the wings? Didn't TFA mention something about wings? Don't *they* have a cooling effect?

Re:arg (1)

tftp (111690) | more than 3 years ago | (#36639940)

Didn't TFA mention something about wings? Don't *they* have a cooling effect?

A thing that burns megajoules can't have a cooling effect overall. It will have heating effect, to the exact amount of energy expended.

All the fuel that an airplane uses up during the flight heats the atmosphere, unless there is a difference in elevation between the origin and the destination airports.

Re:arg (0)

Anonymous Coward | more than 3 years ago | (#36639092)

RTFA ... they are talking about jets with propellors. Gave me a brief chuckle, then ignore whatever ignorant ramble that might be connected to it.

Re:arg (4, Informative)

mcgrew (92797) | more than 3 years ago | (#36639224)

Oh, ferkrissakes, I came here to use up my last two mod points and almost every comment is ignorant, so I'm going to just make one comment and watch a movie and use those two points in the morning.

I know it's not usual for anybody to RTFA and instead just jump to conclusions thinking you know everything without having a clue, so I'm going to clue a few of you guys. This is not about contrails. Of course contrails have been known about forever. I didn't read this particular FA but I saw another FA about this earlier today, and it was damned interesting.

If it was about contrails, most of you guys would still be wrong. Contrails aren't caused by the turbines, they're caused by the air passing the wingtips of the aircraft. If you want to learn more, there's wikipedia for that.

This is about circular holes in clouds, It's about the exact OPPOSITE if contrails. The cause of contrails is well known, the cause of this particular phenomena isn't known. I find it hilarious that you guys think you know more about physics than folks who've been studying physics all their lives.

I'm not a physicist or meteorologist, but at least I know enough to know the limits of my own ignorance, so I READ. Voraciously. The more I read the more I learn, the more I learn the more I understand how ignorant I am. You guys might try reading once in a while. You're ignorant -- we're all ignorant. A physicist doesn't know shit about cosmology, and a cosmologist doesn't know shit about paleontology.

The man who thinks he knows everything cannot learn. Thus endeth the lesson, grasshopper.

Re:arg (4, Informative)

AnObfuscator (812343) | more than 3 years ago | (#36639382)

If it was about contrails, most of you guys would still be wrong. Contrails aren't caused by the turbines, they're caused by the air passing the wingtips of the aircraft. If you want to learn more, there's wikipedia for that.

Ironic, considering the tone of your post, but I actually *did* look up (and read) the contrails article on Wikipedia, and you are in fact very wrong. http://en.wikipedia.org/w/index.php?title=Contrail&oldid=436631379 [wikipedia.org]

Contrails (play /kntrelz/; short for "condensation trails") or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines. As the hot exhaust gases cool in the surrounding air they may precipitate a cloud of microscopic water droplets. If the air is cold enough, this trail will be comprised of tiny ice crystals.[1]

The wingtip vortices which trail from the wingtips and wing flaps of aircraft are sometimes partly visible due to condensation in the cores of the vortices. Each vortex is a mass of spinning air and the air pressure at the centre of the vortex is very low. These wingtip vortices are not the same as contrails.

Re:arg (1)

excelsior_gr (969383) | more than 3 years ago | (#36640360)

And you missed the point, in which the GP was saying that the article has nothing to do with contrails, it is about a whole different phenomenon altogether.

You shall be now asked to leave the shaolin temple, and leave your geek card at the exit...

Re:arg (1)

Greymoon (834879) | more than 3 years ago | (#36639678)

Thank you for reminding me you are ignorant and apparently fail at taking your own advice. Try being more pretentious next time, the asshole in you wants to be free. ... as in speech.

Re:arg (0)

Beelzebud (1361137) | more than 3 years ago | (#36638814)

Oh shut up about your tax money. Your share of their funds is probably less than 1 dollar per year, for valuable research.

Re:arg (1)

MacTO (1161105) | more than 3 years ago | (#36638856)

While the majority of passengers use jets, it wouldn't surprise me if more than half of the planes in the air use that "darn near extinct" technology. You just won't see many of them at a typical international airport for reasons of economy.

(Where are they used: flights that serve smaller communities, short haul flights, transporting goods or doing exploration in remote areas, etc..)

Re:arg (2)

dave420 (699308) | more than 3 years ago | (#36638862)

Turboprop engines are used all over the world, in very large numbers. The US military alone has over 2,421 active aircraft with propellers (not including helicopters, before you ask).

Re:arg (1)

Osgeld (1900440) | more than 3 years ago | (#36638918)

see how much better that sounds over "propeller jetliner"

Re:arg (1)

dave420 (699308) | more than 3 years ago | (#36638974)

What are you talking about? You claimed propellers are nearly extinct, but clearly they are not.

Re:arg (1)

MacTO (1161105) | more than 3 years ago | (#36638980)

Very few people will even understand the word "turboprop", so writers end up using terms that their readers will understand.

Re:arg (1)

Jeff DeMaagd (2015) | more than 3 years ago | (#36639484)

Which is kind of silly, given that the internet is right there to look things up, turboprop is very well defined. Whether turboprop craft are jetliners appears to be ambiguous. It looks like probably not, but I have nothing to be certain.

nope (1)

localoptimum (993261) | more than 3 years ago | (#36638704)

Jetliners do not have propellers. ;)

Re:nope (0)

blair1q (305137) | more than 3 years ago | (#36638800)

They sort of do, in the form of turbofans in their ducted engines.

However, these do not cause cooling. They cause enormous heating. But they cause turbulence in the air behind the plane. This turbulence may constitute enough of a difference in density and pressure to cause water vapor in the air to condense into mist, which is called a contrail.

Airplanes also have wings and control surfaces. Air flowing over these creates vortices. These vortices can constitute enough of a difference in density and pressure to cause water vapor in the air to condense into mist, which is also called a contrail.

And just wait until Mr. Wizard and his government grant get ahold of the idea of the speed of sound...

Re:nope (1)

Loconut1389 (455297) | more than 3 years ago | (#36638822)

and turboprops are both a jet and a propeller

Mystery Fog formed before airplan crash near Katyn (1)

PythonM (2184020) | more than 3 years ago | (#36638744)

Before the 2010 airplane crash that killed Polish president several top generals and tens of top politician, a mystery fog appeared. Could the fog be intentionally formed the Russian airplane that was flying around that place earlier?

Re:Mystery Fog formed before airplan crash near Ka (1)

Wyatt Earp (1029) | more than 3 years ago | (#36638860)

Or it was just a fog.

http://en.wikipedia.org/wiki/Fog#Characteristics [wikipedia.org]

Fog forms when the difference between temperature and dew point is generally less than 2.5 C or 4 F

"Fog can form suddenly, and can dissipate just as rapidly, depending what side of the dew point the temperature is on. This phenomenon is known as flash fog."

Re:Mystery Fog formed before airplan crash near Ka (1)

amorsen (7485) | more than 3 years ago | (#36639894)

Mystery? What exactly was mysterious about it? Are all fogs mystery fogs?

cue the chemtrail jokes... (0)

lemur3 (997863) | more than 3 years ago | (#36638764)

3 2. 1......

surely someone out there will be using this as more "proof"

Spammy Inhabitat link instead of Science Daily. (5, Informative)

couchslug (175151) | more than 3 years ago | (#36638772)

"commercial and private jetliners" "When an airplane flies through a cloud, its propellers"

The number of jetliners with "propellers" is mighty fucking few, though not zero.

Linking to the PARENT Science Daily piece

http://www.sciencedaily.com/releases/2011/06/110630142835.htm [sciencedaily.com]

instead of the pointless Inhabitat bullshit summary would have been nice. There is NO excuse for the Inhabitat link other than SPAM.

AC is anonymous because he/she/it wants page hits for Inhabitat.
Now I know not to visit Inhabitat again. Fuck you too and thanks for nothing.

http://www.sciencedaily.com/releases/2011/06/110630142835.htm [sciencedaily.com]

Re:Spammy Inhabitat link instead of Science Daily. (0)

Anonymous Coward | more than 3 years ago | (#36638898)

if i had points, i'd mod you up. I can't stand inhabitat.

Re:Spammy Inhabitat link instead of Science Daily. (3, Informative)

sphealey (2855) | more than 3 years ago | (#36638940)

> The number of jetliners with "propellers" is mighty fucking few, though not zero.

The number of airliners with gas turbine engines that turn propellers is in fact quite large.

The bypass fan of a high-bypass turbofan engine is essentially a propeller as well, although ducted.

So that leaves us with the various 707s, DC-8s, and 727s and their military equivalents flying around out there with straight turbojet engines having no fan-push component, which is not all that many in 2011.

sPh

In any case the results of this study should have been blindingly obvious to anyone living in North America during the no-fly week of 9/11 - 9/18.

Re:Spammy Inhabitat link instead of Science Daily. (1)

couchslug (175151) | more than 3 years ago | (#36639140)

Technically quite correct, but few readers not greatly interested in aircraft will get those differences between a conventional external "prop", turbojets, and turbofans. I'm prior avionics/engines/crew dog (cross-training was fun) but try to keep it simple for layfolk.

These are kinda neat:

http://www.popsci.com/technology/article/2010-03/naked-engine-cleaner-flights [popsci.com]

Re:Spammy Inhabitat link instead of Science Daily. (1)

FunkSoulBrother (140893) | more than 3 years ago | (#36639352)

I've never been to inhabitat but holy shit did it want to run a lot of javascript. Like 15 different domains.

Re:Spammy Inhabitat link instead of Science Daily. (1)

Wyatt Earp (1029) | more than 3 years ago | (#36640104)

Turboprops make up for 45% of passengers carried by commercial aircraft in the US and Canada.

Anecdotally (-1)

Anonymous Coward | more than 3 years ago | (#36638808)

I am also prone to seeding around the pole.

There is no going back (0)

Anonymous Coward | more than 3 years ago | (#36638816)

Could we possibly not appropriate these results into the militant anti-human greeny litany and then beat ourselves over the head with it? It's such a drag.

This is a human planet. For whatever reason the universe permitted the emergence of a species of engineers. Barring our extinction the planet will never again approach 'natural.' From radioisotope traces to atmospheric disruption the effect of our existence can not be prevented, removed or even hidden.

Contemporary Western culture is presently indulging a crippling self-loathing as it attempts to come to terms with this reality. Yurts aren't an option. Stop polluting your mind with that nonsense.

Fortunately cultures evolve, sometimes rapidly. A day will come when we cease to relegate all analysis of new knowledge of our world and everything in it exclusively to anti-humanists.

Re:There is no going back (4, Insightful)

wierd_w (1375923) | more than 3 years ago | (#36638890)

Conversely, there are fundemental limitations of what this muddy dirtball can handle, and limits to what technology can accomplish.

The ideal course is to understand both, and proceed accordingly.

To do otherwise is to invite disaster.

Re:There is no going back (1)

couchslug (175151) | more than 3 years ago | (#36639152)

Clearly, we must conquer more muddy dirtballs!

Where have I read this before? (3, Funny)

JayTech (935793) | more than 3 years ago | (#36638874)

I remember reading this at a popular news site over a year ago. Where could it have been? Oh, wait, here it is! http://science.slashdot.org/story/10/06/15/2020240/Airplanes-Unexpectedly-Modify-Weather [slashdot.org]

Re:Where have I read this before? (-1)

Anonymous Coward | more than 3 years ago | (#36639112)

The only thing more pointless than the reposts on Slashdot is someone like you, who purposely sits around searching for every article that he's read just to make the same fucking remark.

It's Slashdot. Everyone who reads this shit is aware that the editors post the same crap over and over again. Pointing it out doesn't make you special, it makes you late to the fucking party.

Why has it taken so long for anyone to think... (1)

Red_Chaos1 (95148) | more than 3 years ago | (#36639210)

...of this? I used to wonder about this as a kid at least 15-ish years ago. Even without the stuff about propellers and pressure and such, it seemed obvious that a plane flying through a cloud would set off a reaction from the larger water drops formed from the condensation buildup on the body of it. Said larger drops fall off and through the cloud further causing a reaction.

Of course I never studied it or took it further, so it is quite possible I am wrong, but the point stands that I thought of it long ago, why is it only news now? Surely I am not the only one to think of it?

opens the door for lawsuits? (1)

Joe_Dragon (2206452) | more than 3 years ago | (#36639232)

Just saying saying that some can say the plane cloud seeding spawned a tornado that killed some one / damaged your car / house / other stuff.

Chem-trails and conspiracies (0)

Missing_dc (1074809) | more than 3 years ago | (#36639266)

This almost sounds like a lead in for "scientific excuses" for chemtrails.

Oh, look, its the turbo-props causing the lasting contrail, those jets are not equipped with special sprayers at all.

Re:Chem-trails and conspiracies (1)

Akima (1998920) | more than 3 years ago | (#36640406)

From my research contrails are a completely normal part of air flight. My Grandpa was flying commercial passenger planes long ago. I asked him about it and he told me... "All engines emit water vapour, usually invisible. Given the right atmospheric conditions the vapour will condense into cloud. In the same way that normal cloud appears in many different forms, so contrails can be persistent, non-persistent, thick or thin and so can be short, long, narrow or wide and can remain as cloud similar to the Cirrus that you see at high level on a sunny day. Contrails are usually of ice and at high altitude. I must have released many 1000s of tons of water which became ice and cloud. So far no lumps have fallen on my head!"

I've also found plenty of evidence that chemtrails have been created in many different countries.
Here's a Germany news report which describes how the German Federal Army have been creating chemtrails: http://www.youtube.com/watch?v=51FcITBszj8 [youtube.com]
There are subtitles in the video.
I don't think this is strictly chemtrails, but the Russians perform cloud seeding by adding silver iodide, dry ice and liquid nitrogen to the clouds to cause immediate precipitation: http://englishrussia.com/2011/05/18/manipulating-the-weather/ [englishrussia.com]

So far I have been unable to figure out if there is a way of visually distinguishing the difference between chemtrails and contrails.

Really my point is... when you see artificial clouds in the sky it /might/ be a chemtrail, but it is much more likely to be a completely normal contrail.

Sure... (1)

gavron (1300111) | more than 3 years ago | (#36639422)

Yeah, those private jets over the poles, why DO THEY DO IT??? Stop private planes flying over the poles. All zero of them.

And as others have mentioned, yeah "propellers" on the "jetliners". LOL! Sure.

I would rather blame rich guys with long noses who were originally made of wood.
Sure, it's Pinnochio. Just as real.

Looks like Slashdot let another potsmoker start a thread.

E

Re:Sure... (1)

amorsen (7485) | more than 3 years ago | (#36639904)

Looks like Slashdot let another potsmoker start a thread.

It looks more like "let another potsmoker comment on the article" to me. Planes fly quite far north when they fly e.g. between Europe and North America, and practically all jet planes have fans -- propellers with many blades.

time lapse (1)

Evoluder (669436) | more than 3 years ago | (#36639578)

Oddly enough I made this time lapse with my phone the other day, see jet fly through on the left. http://youtu.be/2VBx1RHFM3c [youtu.be]

Explain California droughts then (1)

keith_nt4 (612247) | more than 3 years ago | (#36639584)

The question i always have, and never get the answer to, when I see articles about these "studies" is: explain droughts in California over the past 30 years. California has a whole lot of air traffic all over the state and yet it goes multiple years on end with very little rain. If this happens so consistently to conclude there's a correlation why does California have droughts...like ever...?

Re:Explain California droughts then (0)

Anonymous Coward | more than 3 years ago | (#36639874)

Planes don't put moisture in the air, duh.

Anyway, as a right libertarian, I understand that these findings prove that Global Warming is a myth, and Al Gore is stupid. It's a scientific fact!

Re:Explain California droughts then (1)

maxume (22995) | more than 3 years ago | (#36640366)

The planes interact with water that is present in the atmosphere. If there is not much water in the air a plane flies through, it won't cause rain.

Re:Explain California droughts then (0)

Anonymous Coward | more than 3 years ago | (#36640396)

Terrible water management, not so much the lack of water. Also combine the fact that northern california supplies water to a DESERT, with lush lawn, pools, etc... yeah.

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