Chemische Zusammensetzung, Umwandlung und Wolkenaktivierungseigenschaften von Submikrometer-Aerosolpartikeln in Abluftfahnen großer Ballungszentren
Zusammenfassung der Projektergebnisse
During the EMeRGe project, we successfully conducted two aircraft field campaigns with the research aircraft HALO, namely EMeRGe-EU (7 research flights) in summer 2017 and EMeRGe-Asia (12 research flights) in spring 2018. The compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) worked well during all flights, providing aerosol mass concentrations of the non-refractory components of submicron particles. Together with the additional gas-phase and particle-phase parameters measured by the EMeRGe-team, a large and unique data set was obtained that covers a large area of Europe and the area off the Chinese coast between the Philippines and Japan at altitudes ranging from below 1 km up to 10 km (Europe) and up to 14 km (Asia). The emission plumes of numerous individual target cities and major population centers were probed at various distances and altitudes. The analysis of all individual plumes and target cities is currently ongoing. A general overview on all vertical profiles showed distinct differences between the data obtained over Europe and those obtained over Asia: We observed higher sulfate mass concentrations in the Asian boundary layer (up to about 4 km altitude) than over Europe, accompanied, but less pronounced by higher ammonium mass concentration. In contrast, the averaged organic mass concentrations was found to be higher in Europe than in Asia. In our project, a special focus was set on secondary aerosol formation from inorganic and organic precursor gases and on photochemical processing of organic aerosol particles during their residence time in the atmosphere. We observed a large variability in the degree of oxygenation (inferred from mass spectral marker ions m/z 43 and 44) in background aerosol and identified emission plumes. However, an assignment of observed plumes to specific emission source regions as well as the determination of plume age turned out to be very difficult. In a case study during EMeRGe-Asia, we followed the plume generated both by the Taichung power plant and the city of Taichung during its downwind evolution. We were able to show that with plume dilution (decreasing CO mixing ratio) the mass concentration of particulate organic and sulfate mass increased, indication secondary aerosol formation from organic and inorganic (SO2) precursors. The degree of oxidation of the organic aerosol also increased with increasing distance to the plume origin. Furthermore, the concentration of cloud condensation nuclei (CCN) increased with photochemical processing, indicating that oxygenated organic aerosol possesses a higher hygroscopicity than freshly emitted organic aerosol. Chemical plume age was estimated by the ratio of the two VOCs toluene and benzene and supported the findings obtained from the mass spectrometer. A second case study in Taiwan as well as data obtained in the London plume yielded comparable results that fit into the same data range when plotting the particle oxidation proxy versus chemical plume age inferred from VOC ratios.
Projektbezogene Publikationen (Auswahl)
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Aircraft-based measurements of aerosol chemical composition in the outflow of Asian megacities during EMeRGe-Asia 2018, 2018 joint 14th iCACGP Quadrennial Symposium and 15th IGAC Science Conference, Takamatsu, Japan, 2018
Kaiser, K., J. Schneider, S. Borrmann, and the EMeRGe-Team
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Cloud condensation nuclei (CCN) measurements with the HALO aircraft during EMeRGe in European and Asian airspace, 2018 joint 14th iCACGP Quadrennial Symposium and 15th IGAC Science Conference, Takamatsu, Japan, 2018
Krüger, O. O., M. L. Pöhlker, C. Pöhlker, B. A. Holanda, T. Klimach, H. Su, Y. Cheng, J. Ditas, D. Sauer, K. Kaiser, J. Schneider, J. P. Burrows, V. Nenakhov, M. D. Andrés Hermándes, U. Pöschl and the EMeRGe team
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Effect of Megacities on the Transport and Transformation of Pollutants on the Regional to Global Scales (EMeRGe): an overview of the HALO airborne campaigns in Europe and Asia, 2018 joint 14th iCACGP Quadrennial Symposium and 15th IGAC Science Conference, Takamatsu, Japan, 2018
Burrows, J.P., M.D. Andrés Hernández, H. Schlager, H. Ziereis, J. Schneider, R. Koppmann, K. Pfeilsticker, U. Platt, A. Zahn, M. Vekroussis, A. Pozzer, C. K. Chou, and P.K. Wang
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Aircraft-based measurements of aerosol chemical composition and processing in the outflow of Asian and European megacities during EMeRGe. EGU General Assembly 2019, Geophysical Research Abstracts, Vol. 21, EGU2019-10361, 2019
Kaiser, K., J. Schneider, S. Borrmann, and the EMeRGe-Team
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Atmospheric Processing and Evolution of Organic Aerosol Emitted from Major European and East Asian Population Centers, 27th IUGG General Assembly, Montreal, 2019
Kaiser, K., J. Schneider, S. Borrmann, E. Förster, M. Neumaier, H. Bönisch, A. Zahn, H. Schlager, H. Ziereis, D. Sauer, B. Amorim Holanda, O.O. Krüger, A. Kalisz Hedegaard, M.D. Andres Hernandez, J.P. Burrows
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Transport and transformation of pollutants in the outflow of megacities: the EMeRGe project in Asia, EGU General Assembly 2019, Geophysical Research Abstracts, Vol. 21, EGU2019-2267, 2019
Andrés Hernández, M.D., J.P. Burrows, H. Schlager, H. Ziereis, J. Schneider, R. Koppmann, K. Pfeilsticker, U. Platt, A. Zahn, M. Vrekoussis, A. Pozzer, C. K. Chou, P.K. Wang, and the EMeRGe team
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Aircraft measurements of nitrous acid in excess of model predictions in the boundary layer and free troposphere, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13607
Schreiner, B., Pfeilsticker, K., Kluge, F., Rotermund, M., Zahn, A., Ziereis, H., Bohn, B., Schneider, J., Kaiser, K., Pozzer, A., and Mertens, M.
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Aircraft-based aerosol composition measurements during the HALO mission EMeRGe: Atmospheric processing of anthropogenic and biomass burning aerosol, European Aerosol Conference, 2020
Kaiser, K., J. Schneider, E. Förster, M. Neumaier, H. Bönisch, A. Zahn, H. Schlager, H. Ziereis, J. Wolf, D. Sauer, L. Eirenschmalz, P. Stock, M. Lichtenstern, B. Amorim Holanda, O. O. Krüger, M. L. Pöhlker, U. Pöschl, A.-M. Blechschmidt, A. B. Kalisz Hedegaard, M. D. Andrés Hernández, J. P. Burrows, and S. Borrmann
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EMeRGe - the Effect of Megacities on the transport and transformation of pollutants on the Regional and Global scales , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19474
Burrows, J. P., Andrés Hernández, M. D., Vrekoussis, M., Chou, C. C.-K., Wang, P. K., Schlager, H., Ziereis, H., Zahn, A., Schneider, J., Pfeilsticker, K., Platt, U., and Kanaya, Y.
