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- ItemNucleation of jet engine oil vapours is a large source of aviation-related ultrafine particles(London : Springer Nature, 2022) Ungeheuer, Florian; Caudillo, Lucía; Ditas, Florian; Simon, Mario; van Pinxteren, Dominik; Kılıç, Doğuşhan; Rose, Diana; Jacobi, Stefan; Kürten, Andreas; Curtius, Joachim; Vogel, Alexander L.Large airports are a major source of ultrafine particles, which spread across densely populated residential areas, affecting air quality and human health. Jet engine lubrication oils are detectable in aviation-related ultrafine particles, however, their role in particle formation and growth remains unclear. Here we show the volatility and new-particle-formation ability of a common synthetic jet oil, and the quantified oil fraction in ambient ultrafine particles downwind of Frankfurt International Airport, Germany. We find that the oil mass fraction is largest in the smallest particles (10-18 nm) with 21% on average. Combining ambient particle-phase concentration and volatility of the jet oil compounds, we determine a lower-limit saturation ratio larger than 1 × 105 for ultra-low volatility organic compounds. This indicates that the oil is an efficient nucleation agent. Our results demonstrate that jet oil nucleation is an important mechanism that can explain the abundant observations of high number concentrations of non-refractory ultrafine particles near airports.
- ItemKnowledge Transfer with Citizen Science: Luft-Leipzig Case Study(Basel : MDPI, 2021) Tõnisson, Liina; Voigtländer, Jens; Weger, Michael; Assmann, Denise; Käthner, Ralf; Heinold, Bernd; Macke, AndreasCommunity-based participatory research initiatives such as “hackAir”, “luftdaten.info”, “senseBox”, “CAPTOR”, “CurieuzeNeuzen Vlaanderen”, “communityAQ”, and “Healthy Air, Healthier Children” campaign among many others for mitigating short-lived climate pollutants (SLCPs) and improving air quality have reported progressive knowledge transfer results. These research initiatives provide the research community with the practical four-element state-of-the-art method for citizen science. For the preparation-, measurements-, data analysis-, and scientific support-elements that collectively present the novel knowledge transfer method, the Luft-Leipzig project results are presented. This research contributes to science by formulating a novel method for SLCP mitigation projects that employ citizen scientists. The Luft-Leipzig project results are presented to validate the four-element state-of-the-art method. The method is recommended for knowledge transfer purposes beyond the scope of mitigating short-lived climate pollutants (SLCPs) and improving air quality.
- ItemA new method to measure real-world respiratory tract deposition of inhaled ambient black carbon(Amsterdam [u.a.] : Elsevier Science, 2019) Madueño, Leizel; Kecorius, Simonas; Löndahl, Jakob; Müller, Thomas; Pfeifer, Sascha; Haudek, Andrea; Mardoñez, Valeria; Wiedensohler, AlfredIn this study, we present the development of a mobile system to measure real-world total respiratory tract deposition of inhaled ambient black carbon (BC). Such information can be used to supplement the existing knowledge on air pollution-related health effects, especially in the regions where the use of standard methods and intricate instrumentation is limited. The study is divided in two parts. Firstly, we present the design of portable system and methodology to evaluate the exhaled air BC content. We demonstrate that under real-world conditions, the proposed system exhibit negligible particle losses, and can additionally be used to determine the minute ventilation. Secondly, exemplary experimental data from the system is presented. A feasibility study was conducted in the city of La Paz, Bolivia. In a pilot experiment, we found that the cumulative total respiratory tract deposition dose over 1-h commuting trip would result in approximately 2.6 μg of BC. This is up to 5 times lower than the values obtained from conjectural approach (e.g. using physical parameters from previously reported worksheets). Measured total respiratory tract deposited BC fraction varied from 39% to 48% during walking and commuting inside a micro-bus, respectively. To the best of our knowledge, no studies focusing on experimental determination of real-world deposition dose of BC have been performed in developing regions. This can be especially important because the BC mass concentration is significant and determines a large fraction of particle mass concentration. In this work, we propose a potential method, recommendations, as well as the limitations in establishing an easy and relatively cheap way to estimate the respiratory tract deposition of BC. In this study we present a novel method to measure real-world respiratory tract deposition dose of Black Carbon. Results from a pilot study in La Paz, Bolivia, are presented. © 2019 The Authors
- ItemFormation and composition of the UTLS aerosol(London : Springer Nature, 2019) Martinsson, Bengt G.; Friberg, Johan; Sandvik, Oscar S.; Hermann, Markus; van Velthoven, Peter F. J.; Zahn, AndreasStratospheric aerosol has long been seen as a pure mixture of sulfuric acid and water. Recent measurements, however, found a considerable carbonaceous fraction extending at least 8 km into the stratosphere. This fraction affects the aerosol optical depth (AOD) and the radiative properties, and hence the radiative forcing and climate impact of the stratospheric aerosol. Here we present an investigation based on a decade (2005–2014) of airborne aerosol sampling at 9–12 km altitude in the tropics and the northern hemisphere (NH) aboard the IAGOS-CARIBIC passenger aircraft. We find that the chemical composition of tropospheric aerosol in the tropics differs markedly from that at NH midlatitudes, and, that the carbonaceous stratospheric aerosol is oxygen-poor compared to the tropospheric aerosol. Furthermore, the carbonaceous and sulfurous components of the aerosol in the lowermost stratosphere (LMS) show strong increases in concentration connected with springtime subsidence from overlying stratospheric layers. The LMS concentrations significantly exceed those in the troposphere, thus clearly indicating a stratospheric production of not only the well-established sulfurous aerosol, but also a considerable but less understood carbonaceous component. © 2019, The Author(s).
- ItemThe Association Between Particulate Air Pollution and Respiratory Mortality in Beijing Before, During, and After the 2008 Olympic and Paralympic Games(Lausanne : Frontiers Media, 2021) Breitner, Susanne; Su, Chang; Franck, Ulrich; Wiedensohler, Alfred; Cyrys, Josef; Pan, Xiaochuan; Wichmann, H.-Erich; Schneider, Alexandra; Peters, AnnetteTo improve ambient air quality during the 2008 Summer Olympic and Paralympic Games, the Chinese Government and Beijing’s municipal government implemented comprehensive emission control policies in Beijing and its neighboring regions before and during this period. The goal of this study was to investigate the association between particulate air pollution and cause-specific respiratory mortality before, during and after the period of the Olympic Games. Further, we wanted to assess whether changes in pollutant concentrations were linked to changes in respiratory mortality. We obtained daily data on mortality due to respiratory diseases (coded as J00-J99 according to the International Classification of Diseases and Related Health Problems 10th revision [ICD10]) and pneumonia (ICD10: J12–18), meteorology, particulate matter less than 10 µm or 2.5 μm in diameter (PM10, PM2.5) and particle number size distribution from official monitoring networks and sites located on the Peking University campus between May 20 and December 1, 2008. We assessed the effects of particulate air pollution on daily respiratory mortality using confounder-adjusted Quasi-Poisson regression models. Furthermore, we estimated air pollution effects for three periods—before (May 20 to July 20, 2008), during (August 1 to September 20, 2008) and after (October 1 to December 1, 2008)—by including interaction terms in the models. We found associations between different particle metrics and respiratory and pneumonia mortality, with more pronounced effects in smaller particle size ranges. For example, an interquartile range increase of 7,958 particles/cm3 in ultrafine particles (particles <100 nm in diameter) led to a 16.3% (95% confidence interval 4.3%; 26.5%) increase in respiratory mortality with a delay of seven days. When investigating the sub-periods, results indicate that a reduction in air pollution during the Olympics resulted in reduced (cause-specific) respiratory mortality. This reduction was especially pronounced for pneumonia mortality. The findings suggest that even a short-term reduction in pollution concentrations may lead to health benefits and that smaller particles in the ultrafine size range may be particularly important for respiratory health.
- ItemImpact of vertical air motions on ice formation rate in mixed-phase cloud layers(London : Springer Nature, 2019) Bühl, Johannes; Seifert, Patric; Engelmann, Ronny; Ansmann, AlbertThe relationship between vertical air velocity at cloud base and primary ice formation has been measured for shallow mixed-phase cloud layers (thickness <380 m) by means of ground-based cloud radar and Doppler lidar. For layers with a cloud-top temperature below −12 °C, an increase of vertical-velocity standard deviation from 0.1 to 1.0 m s−1 leads to an increase in the mass flux of ice water by two orders of magnitude. The cloud layers under study were selected in such a way that secondary ice-formation processes played a minor role, and primary ice formation was the dominant source of ice formation. Phenomenological parameterizations of the ice mass and the ice mass flux as functions of standard deviation of vertical air velocity are given.
- ItemFrom Transfer to Knowledge Co-Production: A Transdisciplinary Research Approach to Reduce Black Carbon Emissions in Metro Manila, Philippines(Basel : MDPI, 2020) Tõnisson, Liina; Kunz, Yvonne; Kecorius, Simonas; Madueño, Leizel; Tamayo, Everlyn Gayle; Casanova, Dang Marviluz; Zhao, Qi; Schikowski, Tamara; Hornidge, Anna-Katharina; Wiedensohler, Alfred; Macke, AndreasAir pollution, which kills an estimated 7 million people every year, is one of the greatest environmental health risks of our times. Finding solutions to this threat poses challenges to practitioners and policymakers alike. Increasing awareness on the benefits of transdisciplinary research in solution-oriented sustainable development projects has led to the establishment of the research project “A Transdisciplinary Approach to Mitigate Emissions of Black Carbon” (TAME-BC). This paper introduces the TAME-BC research setup that took place with Metro Manila, Philippines, case study. The approach integrates BC measurements with technological, socio-political, and health aspects to improve the scientific state of the art, policymaking, transport sector planning, and clinical studies related to air pollution health effects. The first pillar in the setup presents an (1) air quality assessment through aerosol measurements and instrumentation, complemented by a (2) description and assessment of the current policies, technologies, and practices of the transport sector that is responsible for pollution levels in the Philippines, as well as a (3) BC exposure and associated health impacts assessment. The fourth pillar is intercrossing, fostering (4) knowledge co-creation through stakeholder involvement across scales. We argue that this transdisciplinary approach is useful for research endeavors aiming for emission mitigation in rapidly urbanizing regions beyond Metro Manila.
- ItemThe Latin America Early Career Earth System Scientist Network (LAECESS): addressing present and future challenges of the upcoming generations of scientists in the region(London : Springer Nature, 2022) Yáñez-Serrano, Ana María; Aguilos, Maricar; Barbosa, Cybelli; Bolaño-Ortiz, Tomás Rafael; Carbone, Samara; Díaz-López, Stephanie; Diez, Sebastián; Dominutti, Pamela; Engelhardt, Vanessa; Gomes Alves, Eliane; Pedraza, Jenniffer; Saturno, Jorge; Tzompa-Sosa, Zitely A.Early career (EC) Earth system scientists in the Latin America and the Caribbean region (LAC) have been facing several issues, such as limited funding opportunities, substandard scientific facilities, lack of security of tenure, and unrepresented groups equality issues. On top of this, the worsening regional environmental and climatic crises call for the need for this new generation of scientists to help to tackle these crises by increasing public awareness and research. Realizing the need to converge and step up in making a collective action to be a part of the solution, the Latin America Early Career Earth System Scientist Network (LAECESS) was created in 2016. LAECESS’s primary goals are to promote regional networking, foster integrated and interdisciplinary science, organize soft skills courses and workshops, and empower Latin American EC researchers. This article is an initial step towards letting the global science community grasp the current situation and hear the early career LAC science community’s perspectives. The paper also presents a series of future steps needed for better scientific and social development in the LAC region.
- ItemUnravelling New Processes at Interfaces: Photochemical Isoprene Production at the Sea Surface(Columbus, Ohio : American Chemical Society, 2015) Ciuraru, Raluca; Fine, Ludovic; van Pinxteren, Manuela; D’Anna, Barbara; Herrmann, Hartmut; George, ChristianIsoprene is an important reactive gas that is produced mainly in terrestrial ecosystems but is also produced in marine ecosystems. In the marine environment, isoprene is produced in the seawater by various biological processes. Here, we show that photosensitized reactions involving the sea-surface microlayer lead to the production of significant amounts of isoprene. It is suggested that H-abstraction processes are initiated by photochemically excited dissolved organic matter which will the degrade fatty acids acting as surfactants. This chemical interfacial processing may represent a significant abiotic source of isoprene in the marine boundary layer.
- ItemEditorial: Impact of the COVID-19 lockdown on the atmosphere(Lausanne : Frontiers Media, 2022) Fadnavis, Suvarna; Roxy, M.K.; Griessbach, Sabine; Heinold, Bernd; Kaskaoutis, Dimitris G.; Gautam, Ritesh[no abstract available]