Preliminary Data Analysis of the 2023 Boeing ecoDemonstrator Explorer SAF Emissions and Contrail Project

In October 2023, Boeing and NASA conducted a joint flight and ground experiment based out of Paine Field in Everett, Washington. This experiment measured the emissions and contrail properties of a Boeing 737-10 equipped with CFM LEAP-1B engines, utilizing the NASA DC-8 airborne laboratory as a chase aircraft. The experiment measured and evaluated particulate emissions and contrail properties from three fuel types over 11 flights and two ground tests.  In-situ flight measurements on the DC-8 were typically conducted at distances ranging from 1 to 20 nautical miles behind and within a vertical range of +/- 100 feet of the altitude of the 737-10 for both contrail and plume sampling. Atmospheric conditions ranged from ice supersaturation for persistent contrails to subsaturated temporary contrails to non-contrail conditions. The fuels tested included low sulfur Jet A, 100% paraffinic sustainable aviation fuel, and local Jet A.  Significant efforts were made to minimize fuel mixing to avoid contamination with sulfur and/or aromatics across fuel types.

Here we present preliminary data analyses from both the ground test and in-flight measurements, focusing on the measurements of total particles, non-volatile particles measured after passing through a 350C thermal denuder, and ice particle concentration measured using a Cloud Aerosol Spectrometer (CAS) and contrasting the results for different fuel types. Differences in particulate matter with fuel type were also captured by the NASA high-spectral-resolution lidar (HSRL) High Altitude Lidar Observatory (HALO) Water Vapor differential absorption lidar (DIAL) instrument, which sampled approximately 1,000-5,000 ft above the contrails made by the Boeing 737-10.   Challenges of using instruments originally developed for particle measurements in clear air to the more complicated environment of an ice cloud such as a contrail will be discussed.

This presentation will also highlight challenges related to logistics, fuel handling, and sampling in contrails, which highlights the complex interactions between atmospheric chemistry and microphysical processes in cloud formation and ice nucleation. Next steps will encompass future campaign needs, outstanding research questions, and measurement techniques.