SoSmoker, whats the air pressure at 30-40k feet? Do you know a formula for different air pressures at different altitudes? Or you don't need to know that?
I'm a scuba diver, so I know sea level pressure(also known as 1 bar or 1 atmosphere) is equal to ~14.7psi. My guess would be that at 30-40k feet that the pressure would be ~4psi....
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Also, how do you think pressure effects contrails? Also, would 24 hours make a difference between seeing contrails and not seeing contrails(as FDD has described in his area). How quick and how much do the temps at cruising altitude(say 25-40k feet) change. I'm just wondering what the dynamics of the upper atmosphere are like/can be within a short period of time. Thanks
(I pay more attention to earths temps rather than 35k feet above my head).
Edit- whats the normal temps, @ cruising altitude, during the cycles of the year(I'm sure it depends on where you are flying though). For example, on land the average winter temps are 30 degrees, the spring is 65F, the summer is 80F and the fall is 60F. Is the upper atmosphere usually much colder than earths surface? Sorry for inundating you with all the questions.
RON PAUL REVOLUTION
~PEACE~
From wiki........ Who knows how legit it is, I just copied and pasted it though.
The main products of hydrocarbon fuel
combustion are carbon dioxide and water vapor. At high altitudes this water vapor emerges into a cold environment, and the local increase in water vapor can push the water content of the air past
saturation point. The vapor then condenses into tiny water droplets and/or deposits into ice. These millions of tiny water droplets and/or ice crystals form the vapour trail or contrails. The energy drop (and therefore, time and distance) the vapor needs to condense accounts for the contrail forming some way behind the aircraft's engines. The majority of the cloud content comes from water trapped in the surrounding air.[
citation needed] At high altitudes, supercooled water vapor requires a trigger to encourage deposition or condensation. The exhaust particles in the aircraft's exhaust act as this trigger, causing the trapped vapor to rapidly turn to ice crystals. Exhaust vapour trails or contrails usually occur at above 8000 metres (26,000 feet). where the temperature is below -40
°C (-40
°F).
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