Meteorological Observations From Aircraft and Satellites for Contrail Cirrus Evolution Observed in Flight Testing

The uncertainty surrounding the climate impacts of persistent aircraft-induced cirrus (AIC) or condensation trails (contrails) is driving the aviation industry and scientific communities to better understand the roles of aircraft and engine relevant parameters, fuel properties, and the background atmosphere. Given the relatively long timeline for the aviation industry to evolve current fuels and airplane equipage, engagement with the meteorological community is encouraged to improve the ability to forecast impactful, persistent contrails. The work presented here contributes to that goal by providing analyses of in-situ and remotely sensed satellite observations of contrails, which can help improve model accuracy of persistent contrail forming regions.

In October 2023, Boeing and NASA conducted a series of 11 flights in the Pacific Northwest region of the U.S., measuring the emissions and contrail properties of a Boeing 737-10 using the NASA DC-8 airborne platform. The primary goal of the experiment was to evaluate how the use of a very low soot emission engine coupled with low sulfur and paraffinic sustainable aviation fuels affect contrail ice properties. In-situ atmospheric measurements were made on the lead and trailing aircraft, as well as from the GOES-West satellite using the mesoscale mode. For some of the more interesting contrail events observed through satellite data during the test campaign, key analyses will be shown that highlight the importance of better identifying the roles of the aircraft, engine, fuel, and atmospheric properties. This improved understanding can aid in assessing a contrail’s contribution to overall emissions and their impact on the climate, as well as enabling potential mitigation approaches.