EGUsphere EGUsphere EGUsphere EGUsphere Copernicus Publications Göttingen, Germany 10.5194/egusphere-2026-2161 Measurement report: Chemical composition of submicron aerosol and cirrus and contrail ice residuals measured in the UTLS over Germany in winter 2018 Brauner Philipp 1 9 Appel Oliver https://orcid.org/0000-0002-6612-8790 1 2 9 Eppers Oliver https://orcid.org/0000-0001-9487-4603 1 9 Köllner Franziska https://orcid.org/0000-0002-4967-5514 2 1 8 Clemen Hans-Christian https://orcid.org/0000-0002-9518-5268 1 8 Bräuer Tiziana https://orcid.org/0000-0003-2432-5152 3 Lachnitt Hans-Christoph https://orcid.org/0009-0005-4702-3896 2 Kaiser Katharina https://orcid.org/0000-0002-3162-2502 1 8 Schneider Johannes https://orcid.org/0000-0001-7169-3973 1 8 Dragoneas Antonis https://orcid.org/0000-0003-2827-7733 4 Hünig Andreas https://orcid.org/0000-0003-2027-7181 1 9 Molleker Sergej https://orcid.org/0000-0002-2980-0330 5 Anderson Bruce E. 6 Cheng Yafang https://orcid.org/0000-0003-4912-9879 7 8 Schlager Hans 3 Voigt Christiane https://orcid.org/0000-0001-8925-7731 2 3 Borrmann Stephan https://orcid.org/0000-0002-4774-9380 1 2 Particle Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany Institute for Physics of the Atmosphere, Johannes Gutenberg University, Mainz, Germany Institute of Atmospheric Physics, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany Instrument Development and Electronics Department , Max Planck Institute for Chemistry, Mainz, Germany NASA Langley Research Center (LaRC), Hampton, USA Multiphase Chemistry Department , Max Planck Institute for Chemistry, Mainz, Germany now at: SCHOTT AG, Mainz, Germany now: Aerosol Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany 23 04 2026 2026 1 39 Copyright: © 2026 Philipp Brauner et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2161/ The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2161/egusphere-2026-2161.pdf

The knowledge of submicron aerosol composition in the upper troposphere and lower stratosphere (UTLS) and the contribution of aircraft exhaust on the cirrus and contrail formation is still limited due to sparse observations and snapshots not considering the evolution of these clouds. Airborne measurements of the aerosol chemical composition were conducted in the 2018 wintertime UTLS region over Germany. With the help of the hybrid mass spectrometer ERICA (ERC Instrument for the Chemical composition of Aerosols), the composition of background aerosol was analyzed as well as the composition of cloud residuals by applying a counterflow virtual impactor. We found that carbonaceous material plays an important role in the particulate matter in the wintertime UTLS over Germany, among which biomass burning (BB) material is the prevailing species. Complementary simulations of air mass history and synoptical analysis suggest that BB material results from wildfires, in particular the Thomas fire in Northern America. Besides the long-range transport of BB aerosol, the chemical composition of UTLS aerosol is driven by local meteorological conditions. Further, carbonaceous aerosol from aircraft exhaust including soot and engine oil contribute to the aerosol population in the size range below 200 nm. Aging contrails contain signatures of aircraft exhaust such as coated soot and engine oil among other biogenic organic compounds and are consistent with the enhancement of these compounds in aircraft exhaust plumes. Sea spray and mineral dust dominate cirrus residuals, implying the formation at a liquid state.

 Deutsche Forschungsgemeinschaft VO 1504/10-1 428312742 SCHN 1138/8-1 European Research Council 321040