10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Variation in Aircraft Engine Aerosol Emissions with Altitude During the NASA ACCESS Campaign
RICHARD MOORE, Kenneth Thornhill, Edward Winstead, Bernadett Weinzierl, Daniel Sauer, Hans Schlager, Claire Robinson, Michael Shook, Luke Ziemba, Bruce Anderson, NASA
Abstract Number: 1587 Working Group: Combustion-Generated Aerosols: the Desirable and Undesirable
Abstract We present measurements of aerosol emissions indices measured in-situ at various cruise altitudes behind the CFM56-2-C1 engines of the NASA DC-8 aircraft during the 2014 Alternative Fuel Effects on Contrails and Cruise Emissions (ACCESS) project. Aircraft engine emissions can have a disproportionately large climatic impact since they are emitted high in the troposphere and in remote regions with otherwise low aerosol concentrations. This has motivated numerous past ground-based studies focused on quantifying the emissions indices of non-volatile and semi-volatile aerosol species, however, it is unclear the extent to which emissions on the ground translate to emissions at cruise conditions. To better understand these effects, NASA, DLR, and NRC Canada carried out the ACCESS chase plane experiment in 2014. Three different fuel types were investigated including a biofuel blend. Emissions were sampled using a large number of aerosol and gas instruments integrated on HU-25 and Falcon 20 jets that were positioned in the DC-8 exhaust plume at approximately 50-500 m distance behind the engines. It was found that the biojet fuel blend substantially decreases the aerosol number and mass emissions indices, while the gas phase emission indices were similar across fuels. The magnitude of the effects of these fuel-induced changes of aerosol emissions as function of aircraft cruise altitude will be discussed.