Ecologic urgency : Air traffic excess

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 oliverstoned wrote:

“If the cloud was formed by aircraft movement from the "very busy airline" then there would be hundreds of those clouds criss-crossing the sky, not just one, unless all the very busy aircraft follow exactly the same route without disturbing the contrail of the previous arcraft. Contrails are unstable and disperse very quickly, too quickly to "seed" larger copies of themselves - roll-clouds are formed by two pressure systems sliding over each other, just like the tobacco in a hand-rolled cigarette. If you can describe a mechanism where an arcus/roll-cloud can be formed by an aircraft I would love to hear it.” 

So how do you name this cloud? Is it natural, according to you? 
It's called a roll cloud or arcus cloud and of course it is natural, rare, but natural. Ask any meteorologist or nephologist. I'll repeat my question - explain how such a cloud can be created by an aircraft.

 oliverstoned wrote:

“Where is this other layer of atmosphere that is affected by all the other meteorological phenomenon that release water vapour into the air if not between us and the sun??” 

I don’t understand your point, what I said is that air traffic releases its exhausts in high altitude between the sun and us, and since there are too much planes, its exhausts don’t have time to dissipate , that’s why 
We’re seing a lot more contrails than before and even artificial clouds below overbusy airlines. Sometimes we can read a definition of contrails saying that when we see contrails, it means that it’s about to rain (because it forms 
In humid air). It was true ten years ago, it’s not anymore. We had two months of drought here, and we’ve seen contrails almost everyday since the beginning of that drought period and you know why? Because as we’re beyond the threshold of saturation and the huge amount of steam water (& soot) rejected by planes cannot dissipate properly and that’s why the old contrail definition is not valid anymore. We’re disturbing water and light cycles.
There is no evidence that contrails form rain, in fact meteorically it is unlikely. Rain clouds are low altitude, contrails are high altitude. If the atmosphere is more humid (saturated) then there will be rain, not drought - that's pretty basic weather prediction and not related to contrail formation.

 oliverstoned wrote:

“The sun is white and the sky is black. The sun appears yellow (and the sky appears blue) to us because of Rayleigh scattering of the light from the sun by particles in the atmosphere - the more particles (or the thicker the atmosphere) the more yellow the sun and the less blue the sky. This is why the sky is deeper blue overhead and less blue towards the horizon. (read the linked page)” 

Indeed the sunlight from space is white but the atmosphere composition made the light yellow since the dawn of times and until very recently. Children use to take a yellow pencil to color the sun, now they don’t need 
any pencil, just to draw a circle. The layer of pollution from airtraffic also prevents from bright stars, astronomers also complain: 

https://darkskydiary.wordpress.com/tag/contrails/ 

These two effects are unrelated so I fail to see why you group them together. I'll repeat what I have already said - if the sun is less yellow and more white it means that there is less scattering of the shorter blue wavelengths of light reaching our eyes from the sun - this means there is less atmospheric interference. Contrails and other disturbances in the atmosphere would make the sun more yellow.

The astronomers are not complaining about the change in colour of the sun (or the scintillation caused by atmosphere, which is a common effect when observing space from the earth ... hence the need for Hubble Space Telescope), but on the cloud cover in general.

 oliverstoned wrote:

“If you believe that the sun is less yellow than it was then that is because there is less vapour & less pollutants in the atmosphere that there were, not more - ie more of the sun's spectrum is reaching our eyes. “ 

Ho wcan you be so sure? I explained my theory that the black clouds modify not only color of light but also affect the parallelism of lights wich are scattered by the steam water/soot layer.

In this picture white light (the sun) is shinning onto clear glass (the sky) - the blue light in the spectrum is scattered and makes the glass appear blue while the yellow/orange light passes through without scattering and looks yellow/orange in the shadow.

Black clouds are white - they appear black because they absorb all the light that is trying to shining through them - in other words the black is shadow - this is why Nimbostratus (rain clouds) are darker at the bottom - the sunlight does not reach the bottom of the cloud. Of course water droplets refract light - that is how rainbows are formed, but black clouds are not refracting light, they are absorbing it.

 oliverstoned wrote:

“In our lifetime we have seen the effects of Mount St Helen's on sunsets, so the increased "blue" skies following Eyjafjallajökull shouldn't surprise anyone and really cannot be attributed to stopping air traffic for a couple of days.” 

Please be more explicit, I don’t understand. Americans report the same after the 11th Spetember 2001. I can tell you the sun was less blazing during the ban flight, one can look at it much longer than in normal times 
when it’s very blazing.
It is a specious correlation - the clear skies after 9/11 were not caused by banning air flight but by natural weather effects since the skies were clear of all clouds, not just contrails - we need much more data  before we can jump to conclusions to cause and effect - hundreds of days without air traffic, not just a few.

 oliverstoned wrote:

Every body of water on the planet releases "steam" into the atmosphere on a scale vastly greater than anything created by aircraft - every single cloud in the sky is "steam" released from the earth - from seas, rivers, lakes and from the normal "breathing" of plants. The atmosphere on a cloudless day is full of water - it's called humidity. Most of the water in contrails does not come out of the aircraft or its exhaust gasses, most of it was already in the atmosphere before the aircraft took off, the passage of aircraft causes the water vapour in the atmosphere to condense into water droplets, which we see as contrails - this is done by two well documented processes - the first is by reducing the air pressure in the wake of the aircraft which means that the air can no longer "hold" the vapour it contains, and the second is by the relatively small volume of water in the exhaust gasses causing the humidity in the air to exceed its saturation point and so it condenses as a cloud of ice crystals 

Please quote a bigger producer of steam water than a jet plane: there’s not. Boats reject a lot, but you don’t have 100 boats that go the same way in one hour, there are too slow.
Erm... the sun and any movement of surface water (waves, ripples, and rive flow) all produce water vapour in far larger quantities than any number of aircraft - trees also release far more water into the atmosphere than aircraft. For man-made objects I would cite power stations of all types since they all produce electricity from steam. A small cumulus cloud weighs as much as a 747 - and 747's are not made of water - a minute fraction of the weight of a 747 is water (and most of that is contained within the human passengers)

 oliverstoned wrote:

“Not 24 hours. I'm not that blind - the shadows and relative position of the sun is totally different - my guess is there is between 4 and maybe 6 hours difference in the time of day those photographs were taken. In the first photograph the sun is behind the camera, and in the second photograph the sun is much lower in the sky and in front of the camera, which results in the apparent brightness seen by the auto-exposure of the camera. Looking at the palm leaves I don't think these are 5 hours apart on the same day so this means the second photograph is 29 or 53 hours later, but not 24 hours - however, you would have gotten a similar effect if the photographs were taken 5 hours apart on the same day, with or without airtraffic. “ 

Well seen, it’s three hour. One day the sky is deep blue, the day after it’s white Unfortunatly the two pictures were no taken at exactlt the sam ehour but we’d have seen what billions of people noticed 
In the USA in 2001 and in Europe 10 years later. One day it’s deep blue, the day after it’s white. 

You really cannot make subjective statements like this - white skies mean less scattering of sunlight, this means there are less molecules in the air to scatter the light - contrails and aircraft created pollutants would make the sun more yellow and the sky more blue.

To make theses claims based upon photographic "evidence" you have to be more scientific - the photographs have to be taken at exactly the same time of day and pointing in exactly the same direction and with exactly the same exposure time and aperture. You would then have to repeat the experiment every day for months with air traffic and every day for months without air traffic. 

A three hour time difference is significant, I'll repeat (with your verified time corrections¹): you would have gotten a similar effect if you had taken the photographs three hours apart on the same day, with or without air traffic. The sky in the second picture looks more white because the sun is lower in the sky and for no other reason.

_________________
¹ 4 hours 9 minutes. 

Edited by Dean - June 14 2011 at 16:33