Why do jet trails persist?
Show answer & explanation
Answer: Humidity determines persistence
Engines release water vapor — Wrong. Engines do emit water vapor and particles, but persistence depends on atmospheric humidity—dry air = quick dissipation.
Humidity determines persistence ✓ — Correct! Atmospheric conditions! Contrail persistence depends on humidity: (1) Jet engines emit hot exhaust—water vapor + particles. (2) High altitude (-40°C+)—vapor instantly freezes into ice crystals. (3) If air saturated (high humidity)—contrails persist, spread (cirrus clouds). (4) If air dry—ice sublimates (evaporates), disappears minutes. (5) Persistent contrails indicate high-altitude moisture. Not chemtrails conspiracy! Normal ice clouds. Can affect climate slightly—reflect sunlight, trap heat. Grid patterns—multiple flight paths. Contrail cirrus can last hours!
High altitude air is polluted — Wrong. High altitude isn't polluted—contrails are ice crystals from jet exhaust freezing. Persistence depends on humidity, not pollution.
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