Vertical profiles of volatile organic compounds and fine particles in atmospheric air by using an aerial drone with miniaturized samplers and portable devices

The increase in volatile organic compound (VOC) emissions released into the atmosphere is one of the main threats to human health and climate. VOCs can adversely affect human life through their contribution to air pollution directly and indirectly by reacting via several mechanisms in the air to form secondary organic aerosols. In this study, an aerial drone equipped with miniaturized air-sampling systems including up to four solid-phase microextraction (SPME) Arrows and four in-tube extraction (ITEX) samplers for the collection of VOCs, along with portable devices for the real-time measurement of black carbon (BC) and total particle numbers at high altitudes was exploited. In total, 135 air samples were collected under optimal sampling conditions from 4 to 14 October 2021 at the boreal forest SMEAR II station, Finland. A total of 48 different VOCs, including nitrogen-containing compounds, alcohols, aldehydes, ketones, organic acids, and hydrocarbons, were detected at different altitudes from 50 to 400 m above ground level with concentrations of up to 6898 ng m−3 in the gas phase and 8613 ng m−3 in the particle phase. Clear differences in VOC distributions were seen in samples collected from different altitudes, depending on the VOC sources. It was also possible to collect aerosol particles by the filter accessory attached on the ITEX sampling system, and five dicarboxylic acids were quantified with concentrations of 0.43 to 10.9 µg m−3. BC and total particle number measurements provided similar diurnal patterns, indicating their correlation. For spatial distribution, BC concentrations were increased at higher altitudes, being 2278 ng m−3 at 100 m and 3909 ng m−3 at 400 m. The measurements aboard the drone provided insights into horizontal and vertical variability in BC and aerosol number concentrations above the boreal forest.</p

Finnish Centre of Excellence in Physics, Chemistry, Biology and Meteorology of Atmospheric Composition and Climate Change : summary and outlook

Peer reviewe

The Center of Excellence in Atmospheric Science (2002–2019) — from molecular and biological processes to the global climate

The study of atmospheric processes related to climate requires a multidisciplinary approach, encompassing physics, chemistry, meteorology, forest science, and environmental science. The Academy of Finland Centre of Excellence in atmospheric sciences (CoE ATM) responded to that need for 18 years and produced extensive research and eloquent results, which are summarized in this review. The work in the CoE ATM enhanced our understanding in biogeochemical cycles, ecosystem processes, dynamics of aerosols, ions and neutral clusters in the lower atmosphere, and cloud formation and their interactions and feedbacks. The CoE ATM combined continuous and comprehensive long-term in-situ observations in various environments, ecosystems and platforms, ground- and satellitebased remote sensing, targeted laboratory and field experiments, and advanced multi-scale modeling. This has enabled improved conceptual understanding and quantifications across relevant spatial and temporal scales. Overall, the CoE ATM served as a platform for the multidisciplinary research community to explore the interactions between the biosphere and atmosphere under a common and adaptive framework

Analysis of PAH compounds in soil with on-line coupled pressurised hot water extraction-microporous membrane liquid-liquid extraction-gas chromatography

Pressurised hot water extraction (PHWE) was coupled on-line with microporous membrane liquid-liquid extraction (MMLLE) and gas chromatography (GC) in the analysis of polycyclic aromatic hydrocarbon (PAH) compounds in soil. The MMLLE serves as a trapping device after the PHWE. Water from PHWE is directed to the donor side of the membrane unit and the analytes are extracted to the acceptor solution on the other side of the membrane. The role of MMLLE is to clean and concentrate the extract, which is then transferred on-line to the GC via a sample loop and an on-column interface using partially concurrent solvent evaporation. Separate optimisation of MMLLE and simulations of the PHWE-MMLLE connection were carried out before the actual on-line coupling. After optimisation of the whole on-line system, the efficiencies of the PHWE-MMLLE-GC and PHWE-solid-phase trap extractions were compared. The PHWE-MMLLE-GC method allowed on-line analysis of soil samples. The method was linear, with limits of detection in the range 0.05-0.13 ng and limits of quantification 0.65-1.66 wg gm1. Comparison of the results with those obtained by other techniques confirmed the good performance

[Progress in Machine Translation, ed. Sergei Nirenburg. Amsterdam: IOS Press, 1993.] KIELIKONE Machine Translation Workstation

The great majority of Finns speak a language which differs radically from main Indo-European languages. Finnish is highly inflectional and words have potentially thousands of distinct forms. Word forms carry syntactic information in their suffixes and therefore word order is relatively free in Finnish sentences. Because Finnish is syntactically so different from most other Western languages, Finns face a higher language barrier than other Western Europeans do. Increasing foreign trade has forced major Finnish companies to systematically look for ways of making language translation more productive. Machine translation would of course seem to provide an ideal solution, but in practice both the state-of-the-art of MT research and the lack of computational models of Finnish have so far discouraged the companies in their attempts to apply MT software to alleviate the translation load. SITRA Foundation in Finland is a public fund which allocates money for projects of notable national importance. In 1982 SITRA established the KIELIKONE project for the purpose of designing computational models of the Finnish language. The short term goals were to obtain concrete language technology products; the simultaneous long term goal was to build an infrastructure for MT research. During its period of activity so far the project has designed, implemented, and introduced to the market various software products for th

Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry in the identification of organic compounds in atmospheric aerosols from coniferous forest

Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOF-MS) was applied in the identification of organic compounds in atmospheric aerosols from coniferous forest. The samples were collected at Hyytiälä, Finland, as part of the QUEST campaign, in Spring 2003. Manual and automated search procedures were compared in the identification. An automated procedure is preferable when a large number of data files need to be processed; but manual search was more accurate with the present samples, where the number of compounds was large and most of the compounds of interest were present at trace level. Altogether, about 50 compounds were identified on the basis of mass spectra and linear retention indices. The identified compounds included oxidised monoterpenes, acyclic alkanes, alkenes, ketones and aldehydes, as well as a few alcohols, acids, and aromatic compounds. © 2006 Elsevier B.V. All rights reserved

Characterization of organic compounds in 10- to 50-nm aerosol particles in boreal forest with laser desorption -ionization aerosol mass spectrometer and comparison with other techniques

The aim of this study was to characterize the organic composition of ambient ultrafine particles (< 50 nm) in a boreal forest environment and compare the analytical results obtained by different techniques with use a data analysis software. In the chromatographic techniques, particles were collected on a filter and analyzed off-line after sample preparation, whereas in the aerosol MS, particle analysis was performed directly from the particle source.Many compounds and chemical groups were identified with a laser aerosol mass spectrometer (laser AMS) and selected organic compounds, including acids, polyols, amines and aldehydes, from 50 nm filter samples were quantified. Interesting components found with the laser AMS included oxygenated and aliphatic hydrocarbons, aromatic compounds, amines, and black carbon. The amines found on laser AMS may be related to new particle formation events at particle sizes 10-25 nm. Correlations between the results obtained with different instruments were clarified, and the best correlations were found between laser AMS and 50-nm size filter samples. There were no correlations between the laser AMS data and meteorological data or on-line measured gas phase compounds. The black carbon found on laser AMS had moderate correlation for levoglucosan found on all-sized filter samples. Finally, the correlation analysis revealed that the information obtained from sub-50-nm size range particles and results for particles several times higher could not be directly compared. (C) 2011 Elsevier Ltd. All rights reserved