We present in-situ observations of vertically resolved particle chemical composition in the summertime Arctic lower troposphere. Our analysis demonstrates the strong vertical contrast between particle properties within the boundary layer and aloft. Emissions from vegetation fires and anthropogenic sources in northern Canada, Europa, and East Asia influenced particle composition in the free troposphere. Organics detected in Arctic aerosol particles can partly be identified as dicarboxylic acids.
We present in-situ observations of vertically resolved particle chemical composition in the...
Review status: a revised version of this preprint is currently under review for the journal ACP.
Chemical composition and source attribution of submicron aerosol particles in the summertime Arctic lower troposphere
Franziska Köllner1,a,Johannes Schneider1,Megan D. Willis2,b,Hannes Schulz3,Daniel Kunkel4,Heiko Bozem4,Peter Hoor4,Thomas Klimach1,Frank Helleis1,Julia Burkart2,c,W. Richard Leaitch5,Amir A. Aliabadi5,d,Jonathan P. D. Abbatt2,Andreas B. Herber3,and Stephan Borrmann4,1Franziska Köllner et al.Franziska Köllner1,a,Johannes Schneider1,Megan D. Willis2,b,Hannes Schulz3,Daniel Kunkel4,Heiko Bozem4,Peter Hoor4,Thomas Klimach1,Frank Helleis1,Julia Burkart2,c,W. Richard Leaitch5,Amir A. Aliabadi5,d,Jonathan P. D. Abbatt2,Andreas B. Herber3,and Stephan Borrmann4,1
Received: 20 Jul 2020 – Accepted for review: 27 Jul 2020 – Discussion started: 03 Aug 2020
Abstract. We use airborne measurements of aerosol particle composition to demonstrate the strong contrast between particle sources and composition within and above the summertime Arctic boundary layer. In-situ measurements from two complementary aerosol mass spectrometers, the ALABAMA and the HR-ToF-AMS, with black carbon measurements from an SP2 are presented. Particle composition analysis was complemented by trace gas measurements, satellite data, and air mass history modeling to attribute particle properties to particle origin and air mass source regions. Particle composition above the summertime Arctic boundary layer was dominated by chemically aged particles, containing elemental carbon, nitrate, ammonium, sulfate, and organic matter. From our analysis, we conclude that the presence of these particles was driven by transport of aerosol and precursor gases from mid-latitudes to Arctic regions. Particularly, elevated concentrations of nitrate, ammonium, and organic matter coincided with time spent over vegetation fires in northern Canada. In parallel, those particles were largely present in high CO environments (> 90 ppbv). Additionally, we observed that the organic-to-sulfate ratio was enhanced with increasing influence from these fires. Besides vegetation fires, particle sources in mid-latitudes further include anthropogenic emissions in Europe, North America, and East Asia. The presence of particles in the Arctic lower free troposphere correlated with time spent over populated and industrial areas in these regions. Further, the size distribution of free tropospheric particles containing elemental carbon and nitrate was shifter to larger diameters compared to particles present within the boundary layer. Moreover, our analysis suggests that organic matter when present in the Arctic free troposphere can partly be identified as low-molecular weight dicarboxylic acids (oxalic, malonic, and succinic acid). Particles containing dicarboxylic acids were largely present when the residence time of air masses outside Arctic regions was high. In contrast, particle composition within the marine boundary layer was largely driven by Arctic regional processes. Air mass history modeling demonstrated that alongside primary sea spray particles, marine-biogenic sources contributed to secondary aerosol formation by trimethylamine, methanesulfonic acid, sulfate, and other organic species.
We present in-situ observations of vertically resolved particle chemical composition in the summertime Arctic lower troposphere. Our analysis demonstrates the strong vertical contrast between particle properties within the boundary layer and aloft. Emissions from vegetation fires and anthropogenic sources in northern Canada, Europa, and East Asia influenced particle composition in the free troposphere. Organics detected in Arctic aerosol particles can partly be identified as dicarboxylic acids.
We present in-situ observations of vertically resolved particle chemical composition in the...