11:30am - 11:45amTH2-1: 1
Chemical Composition, Mixing State, and Sources of Arctic Aerosols During the ARTofMELT Expedition
Diego Fellin1,2, Liine Heikkinen3,4, Fredrik Mattsson3,4, Julia Kojoj3,4, Claudia Mohr3,4,5,6, Ilona Riipinen3,4, Paul Zieger3,4, Luisa Ickes7, Elena Barbaro1,2, Andrea Gambaro1, Stefania Gilardoni2
1Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Italy; 2Institute of Polar Sciences, National Research Council, Italy; 3Department of Environmental Science, Stockholm University, Sweden; 4Bolin Centre for Climate Research, Sweden; 5Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Switzerland; 6Department of Environmental Systems Science, ETH Zurich, Switzerland; 7Department of Space, Earth and Environment, Chalmers University of Technology, Sweden
The ARTofMELT expedition (May–June 2023) aboard the research icebreaker Oden offered a unique opportunity to investigate Arctic aerosol properties during the spring-to-summer transition. Using a combination of Nano-IR, Total Carbon, and HR-ToF-AMS analyses, we characterized accumulation- and Aitken-mode particles, examining variability in their loading and composition, as well as their mixing state and microphysical properties. These findings will help improve our understanding of aerosol-cloud interactions in a poorly observed region during this critical seasonal transition, shedding light on processes involved in the onset of sea-ice melt.
11:45am - 12:00pmTH2-1: 2
Sea Ice as a Source of Biological Ice Nucleation Particles in the Arctic Atmosphere
Lasse Jensen1, Jennie Spicker Schmidt1, Gabriel Freitas2, Martina D’Agostino1, Camille Mavis3, Lotte Dyrholm Thomsen1, Eva R. Kjærgaard1, Dorte Søgaard1,4, Bernadette Rosati1, Marianne Glasius1, Merete Bilde1, Jessie Creamean3, Lars Chresten Lund-Hansen1, Paul Zieger2, Kai Finster1, Tina Santl-Temkiv1
1Aarhus University, Denmark; 2Stockholm University, Sweden; 3Colorado State University, USA; 4Greenland Climate Research Centre, Greenland
The Arctic oceans are a quantitatively important reservoir for biological ice nucleating particles (bioINPs). These are emitted to the atmosphere through sea spray, and are linked to Arctic cloud formation. Due to accelerated sea ice melt, sea ice microorganisms are progresively discharged into the surface waters, potentially contributing to marine bioINPs. We used field experiments and laboratory simulations to investigate bioINPs in fast and pack ice, looked into physical and microbial factors driving bioINP concentrations, as well as emissions of bioINPs from melted sea ice. Our results will be essential for constraining future climate change predicions for the Arctic region.
12:00pm - 12:15pmTH2-1: 3
Investigation of the chemical composition of Arctic Organic Aerosols
Lotte Thomsen1, Martine Rasmussen1, Celine R. Frederiksen1, Alina Mostovaya2, Jennie S. Schmidt3, Julia Kojoj4, Christian D. F. Castenschiold3, Tina Santl-Temkiv3, Paul Zieger4, Johnna M. Holding2, Merete Bilde1, Marianne Glasius1
1Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark; 2Department of Ecoscience, Aarhus University, 8000 Aarhus C, Denmark; 3Department of Biology, Aarhus University, 8000 Aarhus C, Denmark; 4Department of Environmental Science, Stockholm University, 114 18 Stockholm, Sweden
Arctic aerosols were collected during the ARTofMELT expedition and during two ground-based field campaigns in Disko Bay (West Greenland) and Young Sound (East Greenland), followed by analysis using ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-MS). Aerosol samples from ARTofMELT showed the presence of compounds derived from oceanic fatty acids and monoterpenes, among others. Primary marine aerosols influence the composition at Young Sound. Aerosol samples from Disko Bay show a correlation between monoterpene-derived oxidation products indicating long-range transport from marine or terrestrial monoterpene sources. A comparison between the field measurements will provide a large-scale analysis of the Arctic environment.
12:15pm - 12:30pmTH2-1: 4
Influence of free tropospheric aerosols on the microphysical and radiative properties of a coupled low-level cloud in the central Arctic: a case study from the ARTofMELT expedition
Roman Pohorsky1, Radiance Calmer1, Berkay Dönmez1, Ian Brooks2, Heather Guy2, Paul Zieger3, Lea Haberstock3, Julia Kojoj3, Nicolas Fauré4, Sonja Murto5, Michael Tjernström5, Jessie Creamean6, Julia Schmale1
1Extreme Environments Research Laboratory, Ecole Polytechnique Fédérale de Lausanne, Sion, 1950, Switzerland; 2School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, U.K.; 3Department of Environmental Science and Bolin Centre for Climate Research, Stockholm University, Stockholm, SE-106 91, Sweden; 4Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, SE-41296, Sweden; 5Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, SE-106 91, Sweden; 6Department of Atmospheric Science, Colorado State University, Fort Collins, CO, 80523, USA
Low-level mixed-phase clouds in the Arctic strongly influence the surface energy balance, but their representation in models remains poorly constrained due to large uncertainties on aerosol-cloud interaction processes. Combining detailed in situ aerosol and cloud measurements, collected from a tethered-balloon system in the central Arctic in June 2023, with modeling approaches, this case study quantifies the contribution of entrained free tropospheric aerosols to the cloud’s number of droplets and radiative properties. These findings highlight the need for more systematic vertical aerosol-cloud profiling to improve our knowledge of free tropospheric aerosol characteristics and their influence on clouds’ radiative properties.
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