http://bolin.su.se/data/oden-ao-2018-mart-aerosol-type-1 Jessica A. Mirrielees, Rachel M. Kirpes, Patricia A. Matrai, Kerri A. Pratt Bolin Centre Database 2024 Datafile Atmosphere Aerosols Aerosol chemical properties Marine Sea spray aerosol Electron microscopy CCSEM-EDX Particle type number fraction Marine aerosol reference tank AO2018 AO18 MOCCHA Icebreaker Oden Earth science > Atmosphere > Aerosols Jessica Mirrielees 2024-06-05T05:22:47+00:00 English 1 The data are provided in one comma-separated values (csv) file (~2 kB). File structure (columns) and contents: 1. name of experiment (description of water sampling location) 2. date (DD/MM/YYYY) 3. time (when surface water was sampled) in UTC (HH:MM) 4. latitude (water sampling location) 5. longitude (water sampling location) 6. number fraction of submicron aerosol particles classified as sea salt 7. ±95% CI of number fraction of submicron aerosol particles classified as sea salt 8. number fraction of submicron aerosol particles classified as organic 9. ±95% CI of number fraction of submicron aerosol particles classified as organic 10. number fraction of submicron aerosol particles classified as mineral dust 11. ±95% CI of number fraction of submicron aerosol particles classified as mineral dust 12. number fraction of supermicron aerosol particles classified as sea salt 13. ±95% CI of number fraction of supermicron aerosol particles classified as sea salt 14. number fraction of supermicron aerosol particles classified as organic 15. ±95% CI of number fraction of supermicron aerosol particles classified as organic 16. number fraction of supermicron aerosol particles classified as mineral dust 17. ±95% CI of number fraction of supermicron aerosol particles classified as mineral dust Aerosol particles were sampled from the MART using a 10-stage rotating micro-orifice uniform deposit impactor (MOUDI, model 120R, MSP Corp.) at a flow rate of 3.5 LPM. An additional 26.5 LPM of particle-free air (filtered with a 1.2 µm pore size HEPA capsule, Pall Life Sciences) resulted in a total flow rate of 30 LPM to the MOUDI. The MOUDI collected particles on transmission electron microscopy (TEM) grids, silicon, and quartz (Ted Pella, Inc) on four stages (< 0.056 µm, 0.1⁠ – ⁠0.18 µm, 0.32⁠ – ⁠0.56 µm, and 1.0⁠ – ⁠1.8 µm aerodynamic diameter) for subsequent offline single-particle analysis. Following particle collection, the substrates were stored in the dark at room temperature (Laskina et al. 2015) Sample analysis using computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (CCSEM-EDX) was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility located at the Pacific Northwest National Laboratory (PNNL) and sponsored by the Office of Biological and Environmental Research of the U.S. Department of Energy. CCSEM-EDX was used to analyze individual particles collected on TEM grids from the MOUDI stages corresponding with the aerodynamic diameter ranges 0.1⁠ – ⁠0.18 µm, 0.32⁠ – ⁠0.56 µm, and 1.0⁠ – ⁠1.8 µm. Approximately 1500 individual particles were analyzed per TEM grid (39,533 total particles from the MIZ, NP, IF1-4, IF+A, OP, and MP MART experiments). An FEI Quanta environmental scanning electron microcope (SEM) with a field emission gun operating at an accelerating voltage of 20 kV and beam current 0.48 nA was used for the CCSEM-EDX analysis. A scanning transmission electron microscopy high angle annular dark field (STEM HAADF) detector was used for SEM images and CCSEM-EDX for particles collected on TEM grids. An EDX spectrometer (EDAX, Inc.) was used to collect X-ray spectra and quantify the relative atomic abundance of the elements C, N, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Fe, Ni, and Zn for individual particles collected on TEM grids. The EDX spectra of individual aerosol particles were grouped based on similarities in elemental composition into 20 clusters using K-means clustering (Ault et al. 2012) and subsequently combined into three particle types (sea salt particles, organic aerosol particles, and mineral dust). The marine aerosol reference tank experiments were carried out during the Arctic Ocean 2018 expedition on board the Swedish icebreaker Oden, which was made in collaboration between Sweden and the US National Science Foundation (NSF) and organized by the [Swedish Polar Research Secretariat](https://polarforskningsportalen.se/en/arctic/expeditions/arctic-ocean-2018). The ship track with latitude and longitude information can be found in the [Navigation, meteorological and surface seawater data from the Arctic Ocean 2018 expedition](https://bolin.su.se/data/oden-ao-2018-navigation-1) data set.