Hama Neggs
Senior Member
I would say the intention is to move large numbers of people from place to place. In other words, commercial aviation. Contrails are an unavoidable side-effect.
Debunked: No persistent contrails in Russia
- Thread starter cmnit
- Start date
I would say the intention is to move large numbers of people from place to place. In other words, commercial aviation. Contrails are an unavoidable side-effect.
Svartbjørn
Senior Member.
Contrails are, basically, man made clouds created by accident. Aircraft use combustion engines to move... just like a car uses a combustion engine to move. As a result, theres hot exhaust which contain tiny little particles of soot.. just like with your car or a chimney. As those tiny particles start to cool, the natural moisture in the air condenses on them and.. water being water, they start to stick together. What we see as a result are condensation trails or "contrails" for short.
The stuff you mentioned before about cloud seeding etc is a totally different mechanic entirely. If you look at aircraft that seed clouds, they have tiny rocket like objects attached above or below the wings that lignite and spread the silver iodide into clouds that are ALREADY there.. they dont create clouds. Contrails are created by the exhaust, as I mentioned before. Further to that, you can find footage from WWI and WWII of propeller driven aircraft creating contrails.. Ill try to hunt it down but there's some gorgeous shots taken over london during the Blitz where you can see the contrails clear as day as the Germans fly over head. Does that answer your question?
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Ross Marsden
Senior Member.
Weather modification / cloud seeding does have an intent; contrails do not - hence the difference.
It is a point of difference.
sirtwentythree
Member
So with this cloud seeding that Russia is doing to drive the rain away, what does it look like compared to contrails? They did it just this past Saturday for the parade, I've been looking for pics but haven't found any good ones that show the sky.
Svartbjørn
Senior Member.
Depending on the aircraft used, seeding usually looks something like this:
What youre seeing is the backside of the wing, viewed from the cockpit with the little silver iodide burner lit. Here's another shot of a slightly different set up on a different plane and from the outside but itll give you an idea of what cloud seeding aircraft look like:
I have no idea what kind of aircraft the russians have access to or if they even actually do the seeding they're talking about, but speaking in general terms itd be something similar to this.
TEEJ
Senior Member.
cloudspotter
Senior Member.
Any particular reason? It's cool and all but I don't see any cloud seeding going on
Svartbjørn
Senior Member.
For shots of the sky with aircraft in it I think Cloud.
cloudspotter
Senior Member.
TEEJ
Senior Member.
I thought that Sirtwentythree was looking for images from the day of the parade? Was he assuming that the sky would appear strange and still show persistent effects?
cloudspotter
Senior Member.
Possibly. I think we need clarification
deirdre
Senior Member.
i think he just wants to know what cloud seeding looks like. obviously they would have done it BEFORE the parade. and into clouds down wind I imagine, unless they are weird.
like does it look like crop dusting? can you see it from the ground? or is it too "light" to see from the ground?
edit um upwind
cloudspotter
Senior Member.
Trailspotter
Senior Member.
I do not think, that there was a cloud seeding near Moscow before the Victory Day Parade on May 9th, 2015. The MODIS satellite images of the day from NASA Worldview show no rain clouds in vicinity (Moscow is in the centre of the images below):
Terra image at about 9:00 UTC (12:00 noon Moscow time)
The Aqua image at about 10:50 UTC
They may have been ready to seed clouds that could potentially rain on the Red Square, but there was no need to do it in Moscow. There were clear sky in the morning and some high altitude cirrus clouds midday.
PS Regarding the thread title. These satellite images shows quite a few persistent contrails formed ahead and within the advancing cirrus band.
Terra image at about 9:00 UTC (12:00 noon Moscow time)
The Aqua image at about 10:50 UTC
They may have been ready to seed clouds that could potentially rain on the Red Square, but there was no need to do it in Moscow. There were clear sky in the morning and some high altitude cirrus clouds midday.
PS Regarding the thread title. These satellite images shows quite a few persistent contrails formed ahead and within the advancing cirrus band.
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Yes, you can't manufacture rain clouds. But planes do of course "manufacture" cirrus clouds, which is what contrails are. But cirrus clouds don't make rain.
Efftup
Senior Member.
Why not? Serious question here.
The comments in the video are a very good explanation of Cloud seeding for people who are not sure.
cirrus clouds are very wispy looking clouds of ice crystals. Is it that they are not dense enough to make precipitation of any kind? a good explanation would certainly help people understand.
The comments in the video are a very good explanation of Cloud seeding for people who are not sure.
cirrus clouds are very wispy looking clouds of ice crystals. Is it that they are not dense enough to make precipitation of any kind? a good explanation would certainly help people understand.
Don't quote me on this, but my understanding is that cirrus clouds are just too insubstantial to create rainfall. They form at high altitudes, where the air is thin and cold and cannot hold much water at all, so the volume of water in a cirrus cloud is tiny compared to the volume in a low, thick, rain-bearing cloud.
cloudspotter
Senior Member.
cloudspotter
Senior Member.
Or Virga. But yes, it evaporates before it reaches the ground
I'm sure I read somewhere that ice crystals falling from cirrus into rain clouds below can actually, in turn, cause the rain cloud to produce precipitation.
cloudspotter
Senior Member.
I think there was a thread about the on Metabunk somewhere. Not sure if it turned out to be true but I can see the thinking behind it, seeding the clouds with ice nuclei
deirdre
Senior Member.
so at 5:10 is really the only 'from a distance' shot. and since the flare is on I assume the silver is being sprayed, but I cant see it because it is too 'light'. and the clouds too dark.
at 2:47 and 3:32 I see a bit... so it looks like crop dusting but a lot 'lighter' (mistier) of a spray
and I thought only Cumulous Nimbus clouds can rain. ? (the dark clouds in that video). so cloud seeding would (presumably) take place into a dark cloud, no?
deirdre
Senior Member.
that's what I was thinking, looks like a very clear day from the video. and cloud seeding doesn't make the rain cloud disappear completely.
deirdre
Senior Member.
@sirtwentythree
the biggest differences are crop dusting and cloud seeding aren't persistant, are NEVER as long a line, don't hold form like a contrail does (its like spraying baby powder) and
the biggest differences are crop dusting and cloud seeding aren't persistant, are NEVER as long a line, don't hold form like a contrail does (its like spraying baby powder) and
- contrails there is always a gap between the engine and the start of a trail.
- crop dusting/cloud seeding, no gap because they are literally spraying something out, like if you squeeze a bottle of baby powder.
sirtwentythree
Member
Thanks for sharing. I actually watched the entire video so I could see as many shots of the sky as possible. I also noticed Youtube has full video of several of the prior year parades. I'll get through those eventually.
SR1419
Senior Member.
In general, cloud seeding is done in clouds that are already producing precipitation- to enhance precipitation (or mitigate hail)- to clear the skies they try to get the rain clouds to rain out prior to reaching a location (i think).
Here is an video of cloud seeding in Texas.
A fair amount of cloud seeding is done from the ground:
http://www.nawcinc.com/photopages/CNG.htm
