thanks all for your comments. I am not a weather expert but I know cirrus clouds from jet trails when I see them, as I said I am a full time sailor with a full view of the sky.
I have seen the jets lay these trails. I have also seen this many times. the only clouds in this picture are jet trails. and further more they spread and block the sun. you might assume these jet trails are cirrus clouds but I seen them laid by the jets and often.
They do look like jet trails here. However, I would like to point out that jet contrails are more or less cirrus clouds, except manmade. Jet contrails are vapor trails that eject moisture into a freezing atmosphere.
from my observations these jet trails spread across the sky and they never use to. nasa calls them spreading persistent contrails, I have seen this happen any time of the year. in the summer at the end of dry spells when the government predicts. the jets come and the weather changes.
Well yes, they can spread like a mat of cirrus, because they bear similar properties--that being deposited water vapor and thus ice crystals. This doesn't always happen of course, as it depends on atmospheric conditions, but it's not unusual.
if the sky is blue and the jets cloud the sky I would say this is weather changing and in effect solar radiation management.
some scientests are calling for solar radiation management.
Jets can cloud the sky, but there is no evidence that it is solar radiation management. There are many proposals for solar radiation management, but conventional atmospheric science explains the behavior of jet contrails to look exactly as depicted on many photographs and youtube videos just fine.
David Keith, a Canadian environmental scientist and Harvard professor, is describing is a controversial form of Geoengineering called Solar Radiation Management.
It may be a crude fix, but, he says it may be just the kind of solution we need to stave off catastrophic climate change in a world that's waited too long to shift away from fossil fuels.
http://www.cbc.ca/thecurrent/episode/2014/12/02/renewable-energy-climate-change/
from my observation and others it has been happening for many years.
Poor David Keith. He was actually a professor at one of the Universities I attended, though I never actually attended one of his classes. Seems like a nice guy though. Kind of sucks that his picture gets posted on the dartboards of some individuals out there.
But on the topic, he mentions "sulfuric acid particles" in the "stratosphere." While many jetliners can climb to the lower stratosphere depending on what latitude it is at (the further south the better), and also their weight, the question here is whether or not they are actually doing it at present. Given the article came out yesterday, it seems to be a subject that is still being discussed. Watching the Tedtalk, he also addresses his reservations on geoengineering, and that he would like more exposure on examining his proposals.
But to get to my point, let's ask some important questions here:
First, is what you see explainable by conventional science? If you look at the photos above, and if you can fathom that jet emissions are water vapor deposited into the atmosphere, and that such depositions are similar to cirrus, then the answer should be a yes.
If the answer is still no, then the next question is, what exactly does one think is being left by aircraft?
Is this being done globally or to a sufficient extent that it actually addresses issues with solar radiation and what not?
Where are these aircraft coming from?
What type of aircraft are they?
What supplies these aircraft?
Are there enough aircraft to do this?
Who runs these aircraft?
At some point, if you keep asking the questions, you might encounter a bit of a brick wall. What David Keith proposes is arguably cheap (at least according to him), but it still seems like a large scale operation that wouldn't be a secret either.
Yes, I meant upwind.
