Most of you are aware of contrails (short for condensation trails): clouds that form behind jets flying high in the troposphere or in the lowest stratosphere. The picture below shows a typical example.
Most of you already are pretty expert in producing clouds in cold air: it happens during very cold days--you can see your breath! These clouds are generally made of cloud drops.
Human contrail?
Contrails can be produced by both jet aircraft and high-flying propeller driven planes. Contrails were first observed in the 1920s and was a great concern in WWII, since they allowed the enemy to see high-flying bombers. Also contrails could make it difficult for such bombers to stay in formation!
Sometimes contrails are hard to see, while other times they fill the sky as shown in the figure below. Why? The chemtrail folks think this is due to enhanced military or geoengineering activity. The truth is that it all depends on how close the atmosphere is to saturation (100% relative humidity). Sometimes the upper atmosphere is very dry, thus you need to add a lot of moisture from aircraft to
A sky with a lot of cirrus clouds is a good sign there is upward motion and an upper atmosphere at saturation.
If you have a situation where the atmosphere is at or near saturation and a region with a lot of aircraft flying in the upper troposphere, you can have HUGE numbers of contrails. Here is an example from the NASA MODIS satellite. Look carefully and you can see the cirrus clouds as well--just as one might expect.
Contrails, as most clouds, have a noticeable effect on the radiation balance of the planet. On one hand they reflect solar radiation and thus cool. On the other, they absorb and re-emit infrared radiaton, both upwards and downwards. This tends to cause warming. Right now the best estimates are that the warming effect will dominate and thus contrails will heat the planet by a small amount. This fact shows why the chemtrails idea of U.S. government geoengineering to stop global warming is such nonsense---contrails warm the planet and thus would NOT be something you would enhance to stop global warming.
I stiil say, "they're" out there.
ReplyDeleteI knew it... the whole thing is a goverment conspircy to make us even more parinod..
ReplyDeleteCome on folks, this is high school chemistry. Whenever a hydrocarbon is combusted in air, the result is always carbon dioxide and water. Did ya ever notice the water dripping from a car's exhaust pipe when is is first driven? Yep, the result of combustion! You don't see drips after the muffler becomes hot because water then exits as steam, which you do see in cold weather as a car's "contrail".
ReplyDeleteTHANK YOU!
DeleteI live in Washington state one sunny day I looked up and seen a white jet plane spray and as it stopped turning back around as it finished its turn exhaust was dissipating a short distance behind the plane. But the cloud remained before the turn. I call bs no wait its swamp gas no its a weather balloon. Their up to something and think we as people are stupid
DeleteEugene you are correct.contrails on hot summer days that last all day in the skys.. More BS coming right at us people.. Not Sheepie !!!!
DeleteWhy are there two large tanks on the planes with spray nozzles on the wings? Why would a contrails stop and start in mid air? Our trees are dieing, our bugs are dieing and it's becoming more difficult to breathe. Pull up above ground world news. Here you will see a list of chemicals along with the aluminum. A pilot that quit the spraying warned us of all the air force agenda. This is no hoax it's real and it's killing people.
DeleteOh yes, a grand experiment was done on this subject! In the 3+ days that airplanes were grounded after 9/11, satellite photos showed a very noticeable clearing of the atmosphere over the US. Yes, the plethora of contrails left by jets does alter the albedo reflection of our atmosphere. Here's a link describing the 2002 study noting the warming caused by the absence of contrails:
ReplyDeletehttp://www.greenmedinfo.com/blog/artificial-weather-revealed-post-9-11-flight-groundings
That isn't a study its a blog post. Find a paper published in a scientific, pier reviewed journal and maybe someone will listen to you.
DeleteI saw an interesting and possibly related phenomenon today as an aircraft passed through a thin cloud. A short trail of condensation appeared behind the entire wing of the plane. Possibly the result of melting and then refreezing of ice crystals as the air is compressed (heated) and then rapidly cooled?
ReplyDeleteDuring and after 9/11 I was working near MSP and for the several days after when the airport was shut down we had severe clear weather. No contrails.
ReplyDeleteAirplanes fly because the higher air velocity over the wing top creates a lower pressure there than at the bottom. As Cliff has pointed out many times in this blog, when you compress air, it heats. Likewise, when you drop its pressure, it cools. When you cool the humid air here at the edge of the ocean, you get fog! You will frequently see this happen when airplanes take off here in Seattle, in San Francisco, and in Los Angeles. During take off acceleration, the wings are set for no lift so speed can be gained quickly, then, when the pilot pulls back on the yoke, large white clouds instantly form on top of the wings as the plane is lifted into the air by the low pressure on those wing tops! Of course, this is most frequently seen in early morning when the air is most humid.
ReplyDeleteAll jets are built to become no moisture and the story about moisture trails IS A TOTAL LIE AND YOU KNOW THIS.
DeleteAh, yes, "chemtrails". Frankly, this one (and those who buy into it) are so boneheaded that any attempt at logical conversation is basically pointless. You'll just be accused of being a "government agent" sent to discredit their "information" with "propaganda."
ReplyDeleteWhat's particularly amusing is how the chemtrails crowd will first try to pass themselves off as know-it-alls about what happens 35,000 feet up, yet when one mentions things like radiosonde skew-T plots you get a big "Huh? You must be a government plant!" In other words, "why should factual data get in the way of my pet conspiracy theory?"
I have seen planes flying at similar altitudes with different contrails. I have seen video from planes at altitude leaving different trails. Is the fuel mixture the same for all jets? Some tend to evaporate more quickly while others tend to linger and spread out not evaporating at all. I have observed both happening at the same time and altitude does not seem to matter.
ReplyDeleteI have seen low flying planes in air that I know is too warm to form ice crystals make dense streams that do not evaporate, while at the same, planes flying much higher in colder air have short trails that evaporate. Something is up but what?
I'm still in awe that humans can fly! I look at those contrails and feel pride and even disbelief at the wonder of our technology. I guess I'm pretty lame, eh?
ReplyDeleteAnyone that knows me well knows that I really hate a good conspiracy theory. However, my view on most theories is that 99% of the ones you find on the Internet are absolute, total bunk produced by people that should be seeking out counseling rather than distributing their delusional ramblings across the Internet. Thanks to a paying customer of mine I currently run a blog about conspiracy theories. My BS meter is constantly aware of so many gullible people who are willing to believe in reptilian overlords and other far fetched stories. Anyways take a look here and you will see what I meen Lukes message conspiracy blog!
ReplyDeleteI don't know you, but thank you. Anyone that complains about the government's inability to pass laws but thinks they're gassing the atmosphere with chemicals needs to read this.
ReplyDeleteThank you for the explanation of how humidity -- or lack of it -- factors into the visibility of contrails. I wonder if the temperature of the air that passes through modern jet engines is also a factor in the apparent increase in observable contrails, especially on high-altitude flight paths? Part of the efficiency factor of jet engines is their ability to more completely "combust" fuel, which I presume would mean higher temperatures at the exhaust side of the engines.
ReplyDeleteGreat site.
ReplyDeleteWell I just wish some of the people who I know could think about their foolish Chicken Little wannabe complex. But no such luck, one says it is the New World Order spraying chemicals to remove the unwanted ones,but never could explain how these chemicals know who to affect.Then another claims they are spraying chemicals to change our DNA. Then there is of course the one who claims they are controlling weather
ReplyDeletehttp://globalskywatch.com/chemtrails/ubbthreads.php?ubb=showflat&Number=6859&an=317#Post6859
ReplyDeleteMore questions and debate need to take place... on the surface, the things we see in the sky do not seem to make sense... if you agree, please do more research.
ReplyDeleteHere is a good counter-point opinion to Cliff's post.
https://www.corbettreport.com/interview-1185-peter-kirby-explains-the-new-manhattan-project/
Dont be stupid , chemtrails DO exist,the aluminum, barium, strontium, and other chemicals used are messing up our planet! the director of the CIA admitted to areal spraying, costing over$5 billion yearly. so now the cat is out of the bag. all your junk science and fancy lies can't nullify the facts. watch geoengineering watch, for clarification.
ReplyDeleteAre we truly meant to believe that Contrails (condensation only) are the result of super clean burning jet engines that do not exhaust unburned fuel. They are all Chem-trails to some degree. You want to do some research on the millions of tonnes of Ozone that is burned to keep these behemoths in the air.
ReplyDeleteThey why are some planes at the same altitude not leaving trails!?!
ReplyDeleteIf they are reengineering, then they know man-made global warming is a hoax.
ReplyDeleteOtherwise they would make us stop doing it.