AERODYNAMIC CONTRAIL EFFECTS WATCHED

摘要

German researchers say aerodynamic condensation trails formed by airflow over an aircraft's wing at high altitude need to be factored into climate models being developed to determine the effect of air traffic on global warming.rnIn certain conditions, says the German aerospace center (DLR), the pressure drop over the wing forms a stream of extremely small ice particles, which grow larger the farther they are from the aircraft, reflecting different wavelengths of light and creating an iridescent trail. While conventional engine contrails generally form in temperature zones and over the poles when the air is colder than 40C, DLR says aerodynamic contrails only form when the air is considerably warmer and there is sufficient water vapor. This makes them more common in the subtropics and tropics.rnWith high traffic growth rates forecast for south Asia, DLR says aerodynamic contrails need to be factored into modeling to determine the role of aviation in climate change.