Originally posted by Quickfix
reply to post by network dude
Usually a hypothetical question, gets a hypothetical answer, just so you know.
The plane being up higher wouldn't make a difference, there still would be a contrail or chem-trail. It being up even higher would make more of a
contrail on your side of the debate, since the moisture in the air is usually higher up and since it is colder up higher it would form the contrail
easier.
It will almost certainly be colder, but there is no guarantee at all that the humidity will be as high.
This site shows atmpspheric soundings at various sites around the British
Isles.
Clicking on any point on the map gives a graph of various measurements - I will use Nottingham for this example - it is the red dot in the middle of
England.
The blue line at the left is the dew point profile, and if you slide your cursor along it you will see the humidity at various heights given in
brackets next to the dew point (which is given as a temperature).
If I set my cursor at the 300mb pressure scale on the left of the graph it shows the altitude to be 29846 feet, dew point to be -63.9 deg C, and
humidity 23%.
2 intervals above on the graph the pressure is 286mb, altitude is 30873 feet (so only 1027 feet higher), and hte dew point is -61.9 - but hte humidity
is now 34% - 11% change in about 1000 feet.
So the difference can be quite large for a small change in altitude.
Henche the video is not evidence of anything, except that the aircraft are flying in differenet atmospheric conditions - you can't even say which is
higher or lower from the persistance of the contrails - it could go either way.
As for the KC-10 - the physics involved in creating aerodynamic contrails is about year 11-12 level.
Do you remember the gas laws? PV=nRT?? If you drop the pressure in a constant volume you also drop the temperature.
Aircraft wings work by dropping the pressure on the top of the wing (so basically the higher pressure underneath pushes upwards), and so the
temperature drops. If the atmospheric conditions are such that the temperature drops to tehpoint where moisture condenses out of the air then of
course you get condensation.
it really is that simple.
And with your response to the video being a hoax, do you have some other video or thread to point to, to show for your what if view point?