Observing links between lifetimes of satellite detectable contrails and aircraft type

Clouds produced by aircraft (contrails) are responsible for over half of the positive radiative forcing from aviation, leading to the proposal of contrail avoidance as a method for mitigating the climate impact of aviation. This requires accurate prediction of the radiative properties of individual contrails, which themselves are highly dependent on the contrail microphysical properties, lifetime and macrophysical evolution along with the background atmospheric state.  In-situ observations have also shown an impact of the generating aircraft and its fuel type on the properties and evolution of contrails. However, these observations are typically made close to the aircraft, with fewer observational constraints for the properties of the longer-lived contrails that drive the majority of the radiative forcing.

Coupling satellite observations of contrails with flight data, we track contrails formed by individual aircraft over the North Atlantic. We find a strong link between aircraft type and contrail lifetime, with newer, more fuel-efficient aircraft forming longer-lived contrails. This relationship is not driven by the aircraft properties, but rather by operational differences in aircraft flight patterns, with the newer types flying higher in this region and so producing contrails with longer lifetimes. We present some encouraging initial evidence of reductions in aircraft soot emissions affecting contrail lifetime.