Standard horizontal air shear when it happens. I live directly below the Melbourne to Adelaide flight path and watch the contrails form about every 70 minutes on days where the upper atmosphere permits.
On days where the north/south wind is low the patterns stay linear and fall.
One days where the north/south winds are high at high altitude the contrails simply flatten and fan out.
If the temperature at altitude contains air that is saturated from vapour they will start to condense the crytallisation of moisture that would otherwise happen several hours later. Like a catalyst to a chain reaction.
That makes very little sense to me?
Some days there's absolutely no trail, some a small trail, and others it's like the things are crop dusters.
I can't imagine an amount of air temp differential and prevailing wind speed and direction that makes that make sense.
Sorry if I'm just too dense to understand you, but at least you learned that geoengineering is a real science with real patents and scientists, and real methods and means to carry it out.
Recap-
=No reasonable amount of air temp difference or windspeed/direction seems to explain 'persistent contrails' as they can be observed
=There is plenty of documented evidence of these 'trails' getting turned on and off mid flight
=There are pictures and video of spray apparatus -even in operation
The truth will come out, and I'm not an idiot, same as the majority of 'theorists', so feel free to share any stuff you have/learn that could set me/us straight. Just remember, logic and reason is paramount, not condescension and name calling.