Dozenten: Prof. Dr. Ch. Kottmeier, Prof. Dr. J. Orphal, Prof. Dr. T. Leisner, Prof. Dr. P. Braesicke, Prof. Dr. A. Fink, PD Dr. M. Höpfner, Prof. Dr. C. Hoose, Prof. Dr. P. Knippertz, PD Dr. M. Kunz, Prof. Dr. J. Pinto
Aircraft-based single particle composition measurements in the Arctic: Detection of amines from marine biogenic sources in aerosol particles and cloud residues
This talk presents aircraft-based measurements of aerosol particle and cloud residue composition conducted during the Arctic field projects NETCARE (July 2014, Resolute Bay) and ACLOUD (May-June 2017, Svalbard). We used the single particle laser ablation aerosol mass spectrometer ALABAMA onboard the research aircraft Polar 6 to measure particle size and composition in the range of 0.2 – 2.5 µm. During ACLOUD, cloud residuals were sampled by means of a counterflow virtual impactor. Additional gas-phase measurements included CO, CO2, and O3. A second aerosol mass spectrometer was operated during NETCARE, but not during ACLOUD.
Trimethylamine (TMA) was detected as an important compound of aerosol particles, especially at low altitudes (0 - 300 m) where more than 80% of all analyzed particles contained organics compounds and about 60% of this subset contained TMA. Furthermore, TMA was more frequently found in smaller particles: 40% of particles between 200 and 400 nm contain TMA, but only about 10% of the particles > 800 nm. Simultaneous detection of methanesulfonic acid (MSA) suggests that TMA is involved in particle formation and growth, stabilizing MSA and other acids.
In contrast, cloud residuals were found to contain triethylamine (TEA). About 80% of the cloud residuals showed signatures of TEA, mainly together with sulfate. TEA has a high Henry's law coefficient, such that we currently hypothesize that TEA is emitted in gaseous form by marine sources and is efficiently taken up in cloud water. Aqueous-phase reactions with MSA may convert TEA to a more stable form, leading to organic aerosol production by clouds.
PD Dr. Johannes Schneider
Max Planck Institut fuer Chemie Mainz
Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU)
Karlsruher Institut für Technologie (KIT)
E-Mail:hape schmid∂imk kit edu
"CS" - KIT-Campus Süd (Universität), Gebäude 30.23 (Physikhochhaus), Seminarraum 13/2
"CN" - KIT-Campus Nord (Forschungszentrum), Gebäude 435 (IMK), Raum 2.05
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