title: Biofuel blending reduces particle emissions from aircraft engines at cruise conditions.
abstract: Aviation-related aerosol emissions contribute to the formation of contrail cirrus clouds that can alter upper tropospheric radiation and water budgets, and therefore climate. The magnitude of air-traffic-related aerosol-cloud interactions and the ways in which these interactions might change in the future remain uncertain. Modelling studies of the present and future effects of aviation on climate require detailed information about the number of aerosol particles emitted per kilogram of fuel burned and the microphysical properties of those aerosols that are relevant for cloud formation. However, previous observational data at cruise altitudes are sparse for engines burning conventional fuels, and no data have previously been reported for biofuel use in-flight. Here we report observations from research aircraft that sampled the exhaust of engines onboard a NASA DC-8 aircraft as they burned conventional Jet A fuel and a 50:50 (by volume) blend of Jet A fuel and a biofuel derived from Camelina oil. We show that, compared to using conventional fuels, biofuel blending reduces particle number and mass emissions immediately behind the aircraft by 50 to 70 per cent. Our observations quantify the impact of biofuel blending on aerosol emissions at cruise conditions and provide key microphysical parameters, which will be useful to assess the potential of biofuel use in aviation as a viable strategy to mitigate climate change.
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Moore
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|Science Systems and Applications, Incorporated (SSAI), Hampton, Virginia, USA.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Thornhill
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.|University of Vienna, Wien, Austria.
authors.forename: Bernadett
authors.initials: B
authors.lastname: Weinzierl
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.|Ludwig Maximillians University, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sauer
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.|Ludwig Maximillians University, Munich, Germany.
authors.forename: Eugenio
authors.initials: E
authors.lastname: D'Ascoli
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.
authors.forename: Jin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lichtenstern
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Scheibe
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Beaton
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|California State University San Bernardino, San Bernardino, California, USA.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Beyersdorf
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|Science Systems and Applications, Incorporated (SSAI), Hampton, Virginia, USA.
authors.forename: John
authors.initials: J
authors.lastname: Barrick
authors.affiliation: NASA Glenn Research Center, Cleveland, Ohio, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Bulzan
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|Bennington College, Bennington, Vermont, USA.
authors.forename: Chelsea A
authors.initials: CA
authors.lastname: Corr
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|NASA Postdoctoral Program, Columbia, Maryland, USA.
authors.forename: Ewan
authors.initials: E
authors.lastname: Crosbie
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Jurkat
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Martin
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Dean
authors.initials: D
authors.lastname: Riddick
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|Science Systems and Applications, Incorporated (SSAI), Hampton, Virginia, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Shook
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Slover
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.|Johannes Gutenberg University, Mainz, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Voigt
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: White
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.|Science Systems and Applications, Incorporated (SSAI), Hampton, Virginia, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Winstead
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Yasky
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Luke D
authors.initials: LD
authors.lastname: Ziemba
authors.affiliation: National Research Council Canada, Ottawa, Ontario, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Brown
authors.affiliation: Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Schlager
authors.affiliation: NASA Langley Research Center, Hampton, Virginia, USA.
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Anderson
mesh_terms: D000336:Aerosols / Q000032:analysis / Q000737:chemistry; D000401:Aircraft / Q000295:instrumentation*; D056804:Biofuels / Q000032:analysis*; D057232:Global Warming / Q000517:prevention & control; D017752:Greenhouse Effect / Q000517:prevention & control; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D001335:Vehicle Emissions / Q000032:analysis* / Q000517:prevention & control*
chemical_list: D000336:Aerosols; D056804:Biofuels; D052638:Particulate Matter; D001335:Vehicle Emissions