Jonathan Williams
@mpic.de
Atmospheric Chemistry Department
Max Planck Institute for Chemistry
RESEARCH INTERESTS
Volatile Organic Compounds
Atmospheric Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Lisa Ernle, Monika Akima Ringsdorf, and Jonathan Williams
Copernicus GmbH
Abstract. The measurement of volatile organic compounds (VOCs) can be influenced by ozone (O3), resulting in sampling artefacts that corrupt the data obtained. Published literature reports both positive (false enhancements of signal) and negative (loss of signal) interference in VOC data due to ozonolysis occurring in the sample gas. To assure good data quality it is essential to be aware of such interfering processes, to characterize them and to try to minimize the impact with a suitable sampling setup. Here we present results from experiments with a sodium thiosulfate ozone scrubber (Na2S2O3), which is a cost-effective and easily applied option for O3 scavenging during gas-phase sampling. Simultaneous measurement of selected organic trace gases using gas chromatography–mass spectrometry and proton transfer reaction–mass spectrometry was performed at different ozone levels (0–1 ppm) and different relative humidities (0 %–80 %). In this way both tropospheric and stratospheric conditions were examined. The measured data show that several carbonyl compounds including acetaldehyde, acetone and propanal show artificial signal enhancement when ozone is present at higher concentrations (> 150 ppb) in dry air, while analytes with double bonds like isoprene (measured with GC-MS) and terpenes show lower signals due to reaction with ozone. Both effects can be eliminated or in the case of sesquiterpenes substantially reduced by using Na2S2O3 impregnated quartz filters in the inlet line. With the chosen scrubbing material, relative humidity (RH) substantially improves the scrubbing efficiency. Under surface conditions between 50 %–80 % RH, the filter allows for accurate measurement of all species examined.
Gisèle Krysztofiak, Valéry Catoire, Thierry Dudok de Wit, Douglas E. Kinnison, A. R. Ravishankara, Vanessa Brocchi, Elliot Atlas, Heiko Bozem, Róisín Commane, Francesco D’Amato,et al.
MDPI AG
Nitrous oxide (N2O) is the fourth most important greenhouse gas in the atmosphere and is considered the most important current source gas emission for global stratospheric ozone depletion (O3). It has natural and anthropogenic sources, mainly as an unintended by-product of food production activities. This work examines the identification and quantification of trends in the N2O concentration from the middle troposphere to the middle stratosphere (MTMS) by in situ and remote sensing observations. The temporal variability of N2O is addressed using a comprehensive dataset of in situ and remote sensing N2O concentrations based on aircraft and balloon measurements in the MTMS from 1987 to 2018. We determine N2O trends in the MTMS, based on observations. This consistent dataset was also used to study the N2O seasonal cycle to investigate the relationship between abundances and its emission sources through zonal means. The results show a long-term increase in global N2O concentration in the MTMS with an average of 0.89 ± 0.07 ppb/yr in the troposphere and 0.96 ± 0.15 ppb/yr in the stratosphere, consistent with 0.80 ppb/yr derived from ground-based measurements and 0.799 ± 0.024 ppb/yr ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer) satellite measurements.
Sergey Osipov, Sourangsu Chowdhury, John N. Crowley, Ivan Tadic, Frank Drewnick, Stephan Borrmann, Philipp Eger, Friederike Fachinger, Horst Fischer, Evgeniya Predybaylo,et al.
Springer Science and Business Media LLC
AbstractIn the Middle East, desert dust is assumed to dominate air pollution, being in permanent violation of public health guidelines. Here we present ship-borne measurements from around the Arabian Peninsula and modeling results to show that hazardous fine particulate matter is to a large extent of anthropogenic origin (>90%), and distinct from the less harmful, coarse desert dust particles. Conventionally, it was understood that desert dust dominates both the fine and coarse aerosol size fractions, which obscures the anthropogenic signal. We find that the annual excess mortality from the exposure to air pollution is 745 (514-1097) per 100,000 per year, similar to that of other leading health risk factors, like high cholesterol and tobacco smoking. Furthermore, anthropogenic pollution particles account for a major part (~53%) of the visible aerosol optical depth. Therefore, in the Middle East anthropogenic air pollution is a leading health risk and an important climatic factor.
N. Wang, G. Pugliese, M. Carrito, C. Moura, P. Vasconcelos, N. Cera, M. Li, P. Nobre, J. R. Georgiadis, J. K. Schubert,et al.
Springer Science and Business Media LLC
Abstract The chemical composition of exhaled breath was examined for volatile organic compound (VOC) indicators of sexual arousal in human beings. Participants (12-male, 12-female) were shown a randomized series of three emotion-inducing 10-min film clips interspersed with 3-min neutral film clips. The films caused different arousals: sports film (positive-nonsexual); horror film (negative-nonsexual); and erotic (sexual) that were monitored with physiological measurements including genital response and temperature. Simultaneously the breath was monitored for VOC and CO2. While some breath compounds (methanol and acetone) changed uniformly irrespective of the film order, several compounds did show significant arousal associated changes. For both genders CO2 and isoprene decreased in the sex clip. Some male individuals showed particularly strong increases of indole, phenol and cresol coincident with sexual arousal that decreased rapidly afterwards. These VOCs are degradation products of tyrosine and tryptophan, precursors for dopamine, noradrenalin, and serotonin, and therefore represent potential breath markers of sexual arousal.
Pascale S. J. Lakey, Andreas Zuend, Glenn C. Morrison, Thomas Berkemeier, Jake Wilson, Caleb Arata, Allen H. Goldstein, Kevin R. Wilson, Nijing Wang, Jonathan Williams,et al.
Royal Society of Chemistry (RSC)
Models were developed to treat Criegee chemistry and estimate gas-phase squalene ozonolysis products under different conditions. Relative humidity can significantly impact human exposure to these products.
Mengze Li, Andrea Pozzer, Jos Lelieveld, and Jonathan Williams
Copernicus GmbH
Abstract. Methane, ethane, and propane are among the most abundant hydrocarbons in the atmosphere. These compounds have many emission sources in common and are all primarily removed through OH oxidation. Their mixing ratios and long-term trends in the upper troposphere and stratosphere are rarely reported due to the paucity of measurements. In this study, we present long-term (2006–2016) northern hemispheric ethane, propane, and methane data from airborne observation in the upper troposphere-lower stratosphere (UTLS) region from the IAGOS-CARIBIC project. The methane and propane observations provide additional information for understanding northern hemispheric ethane trends, which is the major focus of this study. The linear trends, moving averages, nonlinear trends and monthly variations of ethane, methane and propane in 2006–2016 are presented for the upper troposphere and lower stratosphere over 5 regions (whole Northern Hemisphere, Europe, North America, Asia and the rest of the world). The growth rates of ethane, methane, and propane in the upper troposphere are −2.24 % yr−1, 0.33 % yr−1, and −0.78 % yr−1, respectively, and in the lower stratosphere they are −3.27 % yr−1, 0.26 % yr−1, and −4.91 % yr−1, respectively, in 2006–2016. This dataset is of value to future global ethane budget estimates and the optimization of current ethane inventories. The data are publicly accessible at https://doi.org/10.5281/zenodo.6536109 (Li et al., 2022a).
Therese S. Carter, Colette L. Heald, Jesse H. Kroll, Eric C. Apel, Donald Blake, Matthew Coggon, Achim Edtbauer, Georgios Gkatzelis, Rebecca S. Hornbrook, Jeff Peischl,et al.
Copernicus GmbH
Abstract. Fires emit a substantial amount of non-methane organic gases (NMOGs), the atmospheric oxidation of which can contribute to ozone and secondary particulate matter formation. However, the abundance and reactivity of these fire NMOGs are uncertain and historically not well constrained. In this work, we expand the representation of fire NMOGs in a global chemical transport model, GEOS-Chem. We update emission factors to Andreae (2019) and the chemical mechanism to include recent aromatic and ethene and ethyne model improvements (Bates et al., 2021; Kwon et al., 2021). We expand the representation of NMOGs by adding lumped furans to the model (including their fire emission and oxidation chemistry) and by adding fire emissions of nine species already included in the model, prioritized for their reactivity using data from the Fire Influence on Regional to Global Environments (FIREX) laboratory studies. Based on quantified emissions factors, we estimate that our improved representation captures 72 % of emitted, identified NMOG carbon mass and 49 % of OH reactivity from savanna and temperate forest fires, a substantial increase from the standard model (49 % of mass, 28 % of OH reactivity). We evaluate fire NMOGs in our model with observations from the Amazon Tall Tower Observatory (ATTO) in Brazil, Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) and DC3 in the US, and Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) in boreal Canada. We show that NMOGs, including furan, are well simulated in the eastern US with some underestimates in the western US and that adding fire emissions improves our ability to simulate ethene in boreal Canada. We estimate that fires provide 15 % of annual mean simulated surface OH reactivity globally, as well as more than 75 % over fire source regions. Over continental regions about half of this simulated fire reactivity comes from NMOG species. We find that furans and ethene are important globally for reactivity, while phenol is more important at a local level in the boreal regions. This is the first global estimate of the impact of fire on atmospheric reactivity.
Joseph Byron, Juergen Kreuzwieser, Gemma Purser, Joost van Haren, S. Nemiah Ladd, Laura K. Meredith, Christiane Werner, and Jonathan Williams
Springer Science and Business Media LLC
AbstractMonoterpenes (C10H16) are emitted in large quantities by vegetation to the atmosphere (>100 TgC year−1), where they readily react with hydroxyl radicals and ozone to form new particles and, hence, clouds, affecting the Earth’s radiative budget and, thereby, climate change1–3. Although most monoterpenes exist in two chiral mirror-image forms termed enantiomers, these (+) and (−) forms are rarely distinguished in measurement or modelling studies4–6. Therefore, the individual formation pathways of monoterpene enantiomers in plants and their ecological functions are poorly understood. Here we present enantiomerically separated atmospheric monoterpene and isoprene data from an enclosed tropical rainforest ecosystem in the absence of ultraviolet light and atmospheric oxidation chemistry, during a four-month controlled drought and rewetting experiment7. Surprisingly, the emitted enantiomers showed distinct diel emission peaks, which responded differently to progressive drying. Isotopic labelling established that vegetation emitted mainly de novo-synthesized (−)-α-pinene, whereas (+)-α-pinene was emitted from storage pools. As drought progressed, the source of (−)-α-pinene emissions shifted to storage pools, favouring cloud formation. Pre-drought mixing ratios of both α-pinene enantiomers correlated better with other monoterpenes than with each other, indicating different enzymatic controls. These results show that enantiomeric distribution is key to understanding the underlying processes driving monoterpene emissions from forest ecosystems and predicting atmospheric feedbacks in response to climate change.
Nora Zannoni, Pascale S. J. Lakey, Youngbo Won, Manabu Shiraiwa, Donghyun Rim, Charles J. Weschler, Nijing Wang, Lisa Ernle, Mengze Li, Gabriel Bekö,et al.
American Association for the Advancement of Science (AAAS)
Hydroxyl (OH) radicals are highly reactive species that can oxidize most pollutant gases. In this study, high concentrations of OH radicals were found when people were exposed to ozone in a climate-controlled chamber. OH concentrations calculated by two methods using measurements of total OH reactivity, speciated alkenes, and oxidation products were consistent with those obtained from a chemically explicit model. Key to establishing this human-induced oxidation field is 6-methyl-5-hepten-2-one (6-MHO), which forms when ozone reacts with the skin-oil squalene and subsequently generates OH efficiently through gas-phase reaction with ozone. A dynamic model was used to show the spatial extent of the human-generated OH oxidation field and its dependency on ozone influx through ventilation. This finding has implications for the oxidation, lifetime, and perception of chemicals indoors and, ultimately, human health.
Simon F. Reifenberg, Anna Martin, Matthias Kohl, Sara Bacer, Zaneta Hamryszczak, Ivan Tadic, Lenard Röder, Daniel J. Crowley, Horst Fischer, Katharina Kaiser,et al.
Copernicus GmbH
Abstract. Aerosols influence the Earth's energy balance directly by modifying the radiation transfer and indirectly by altering the cloud microphysics. Anthropogenic aerosol emissions dropped considerably when the global COVID-19 pandemic resulted in severe restraints on mobility, production, and public life in spring 2020. We assess the effects of these reduced emissions on direct and indirect aerosol radiative forcing over Europe, excluding contributions from contrails. We simulate the atmospheric composition with the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model in a baseline (business-as-usual) and a reduced emission scenario. The model results are compared to aircraft observations from the BLUESKY aircraft campaign performed in May–June 2020 over Europe. The model agrees well with most of the observations, except for sulfur dioxide, particulate sulfate, and nitrate in the upper troposphere, likely due to a biased representation of stratospheric aerosol chemistry and missing information about volcanic eruptions. The comparison with a baseline scenario shows that the largest relative differences for tracers and aerosols are found in the upper troposphere, around the aircraft cruise altitude, due to the reduced aircraft emissions, while the largest absolute changes are present at the surface. We also find an increase in all-sky shortwave radiation of 0.21 ± 0.05 W m−2 at the surface in Europe for May 2020, solely attributable to the direct aerosol effect, which is dominated by decreased aerosol scattering of sunlight, followed by reduced aerosol absorption caused by lower concentrations of inorganic and black carbon aerosols in the troposphere. A further increase in shortwave radiation from aerosol indirect effects was found to be much smaller than its variability. Impacts on ice crystal concentrations, cloud droplet number concentrations, and effective crystal radii are found to be negligible.
Mengze Li, Gabriel Bekö, Nora Zannoni, Giovanni Pugliese, Mariana Carrito, Nicoletta Cera, Catarina Moura, Pawel Wargocki, Priscila Vasconcelos, Pedro Nobre,et al.
Elsevier BV
E. Gomes Alves, T. Taylor, M. Robin, D. Pinheiro Oliveira, J. Schietti, S. Duvoisin Júnior, N. Zannoni, J. Williams, C. Hartmann, J. F. C. Gonçalves,et al.
Wiley
Volatile isoprenoids regulate plant performance and atmospheric processes, and Amazon forests comprise the dominant source to the global atmosphere. Still, there is a poor understanding of how isoprenoid emission capacities vary in response to ecophysiological and environmental controls in Amazonian ecosystems. We measured isoprenoid emission capacities of three Amazonian hyperdominant tree species - Protium hebetatum, Eschweilera grandiflora, Eschweilera coriacea - across seasons and along a topographic and edaphic environmental gradient in the central Amazon. From wet to dry season, both photosynthesis and isoprene emission capacities strongly declined, while emissions increased among the heavier isoprenoids: monoterpenes and sesquiterpenes. Plasticity across habitats was most evident in P. hebetatum, which emitted sesquiterpenes only in the dry season, at rates that significantly increased along the hydro-topographic gradient from white sands (shallow root water access) to uplands (deep water table). We suggest that emission composition shifts are part of a plastic response to increasing abiotic stress (e.g. heat and drought) and reduced photosynthetic supply of substrates for isoprenoid synthesis. Our comprehensive measurements suggest that more emphasis should be placed on other isoprenoids, besides isoprene, in the context of abiotic stress responses. Shifting emission compositions have implications for atmospheric responses because of the strong variation in reactivity among isoprenoid compounds.
Christiane Voigt, Jos Lelieveld, Hans Schlager, Johannes Schneider, Joachim Curtius, Ralf Meerkötter, Daniel Sauer, Luca Bugliaro, Birger Bohn, John N. Crowley,et al.
American Meteorological Society
Abstract During spring 2020, the COVID-19 pandemic caused massive reductions in emissions from industry and ground and airborne transportation. To explore the resulting atmospheric composition changes, we conducted the BLUESKY campaign with two research aircraft and measured trace gases, aerosols, and cloud properties from the boundary layer to the lower stratosphere. From 16 May to 9 June 2020, we performed 20 flights in the early COVID-19 lockdown phase over Europe and the Atlantic Ocean. We found up to 50% reductions in boundary layer nitrogen dioxide concentrations in urban areas from GOME-2B satellite data, along with carbon monoxide reductions in the pollution hot spots. We measured 20%–70% reductions in total reactive nitrogen, carbon monoxide, and fine mode aerosol concentration in profiles over German cities compared to a 10-yr dataset from passenger aircraft. The total aerosol mass was significantly reduced below 5 km altitude, and the organic aerosol fraction also aloft, indicative of decreased organic precursor gas emissions. The reduced aerosol optical thickness caused a perceptible shift in sky color toward the blue part of the spectrum (hence BLUESKY) and increased shortwave radiation at the surface. We find that the 80% decline in air traffic led to substantial reductions in nitrogen oxides at cruise altitudes, in contrail cover, and in resulting radiative forcing. The light extinction and depolarization by cirrus were also reduced in regions with substantially decreased air traffic. General circulation–chemistry model simulations indicate good agreement with the measurements when applying a reduced emission scenario. The comprehensive BLUESKY dataset documents the major impact of anthropogenic emissions on the atmospheric composition.
Roger Sheu, Tori Hass-Mitchell, Akima Ringsdorf, Thomas Berkemeier, Jo Machesky, Achim Edtbauer, Thomas Klüpfel, Alexander Filippi, Benjamin A. Musa Bandowe, Marco Wietzoreck,et al.
Royal Society of Chemistry (RSC)
Tobacco combustion products in deposited particles and bodily reservoirs enable persistent thirdhand smoke contamination and transport.
Eva Y. Pfannerstill, Anke C. Nölscher, Ana M. Yáñez-Serrano, Efstratios Bourtsoukidis, Stephan Keßel, Ruud H. H. Janssen, Anywhere Tsokankunku, Stefan Wolff, Matthias Sörgel, Marta O. Sá,et al.
Frontiers Media SA
Citation: Pfannerstill EY, Nölscher AC, Yáñez-Serrano AM, Bourtsoukidis E, Keßel S, Janssen RHH, Tsokankunku A, Wolff S, Sörgel M, Sá MO, Araújo A, Walter D, Lavrič J, Dias-Júnior CQ, Kesselmeier J and Williams J (2022) Corrigendum: Total OH Reactivity Changes Over the Amazon Rainforest During an El Niño Event. Front. For. Glob. Change 5:952123. doi: 10.3389/ffgc.2022.952123 Corrigendum: Total OH Reactivity Changes Over the Amazon Rainforest During an El Niño Event
Patrick Dewald, Clara M. Nussbaumer, Jan Schuladen, Akima Ringsdorf, Achim Edtbauer, Horst Fischer, Jonathan Williams, Jos Lelieveld, and John N. Crowley
Copernicus GmbH
Abstract. The reactivity of NO3 plays an important role in modifying the fate of reactive nitrogen species at nighttime. High reactivity (e.g. towards unsaturated volatile organic compounds – VOCs) can lead to formation of organic nitrates and secondary organic aerosol, whereas low reactivity opens the possibility of heterogeneous NOx losses via the formation and uptake of N2O5 to particles. We present direct NO3 reactivity measurements (kNO3) that quantify the VOC-induced losses of NO3 during the TO2021 campaign at the summit of the Kleiner Feldberg mountain (825 m, Germany) in July 2021. kNO3 was on average ∼0.035 s−1 during the daytime, ∼0.015 s−1 for almost half of the nights and below the detection limit of 0.006 s−1 for the other half, which may be linked to sampling from above the nocturnal surface layer. NO3 reactivities derived from VOC measurements and the corresponding rate coefficient were in good agreement with kNO3, with monoterpenes representing 84 % of the total reactivity. The fractional contribution F of kNO3 to the overall NO3 loss rate (which includes an additional reaction of NO3 with NO and photolysis) were on average ∼16 % during the daytime and ∼50 %–60 % during the nighttime. The relatively low nighttime value of F is related to the presence of several tens of parts per trillion by volume (pptv) of NO on several nights. NO3 mixing ratios were not measured, but steady-state calculations resulted in nighttime values between <1 and 12 pptv. A comparison of results from TO2021 with direct measurements of NO3 during previous campaigns between 2008 and 2015 at this site revealed that NO3 loss rates were remarkably high during TO2021, while NO3 production rates were low. We observed NO mixing ratios of up to 80 pptv at night, which has implications for the cycling of reactive nitrogen at this site. With O3 present at levels of mostly 25 to 60 ppbv (parts per billion by volume), NO is oxidized to NO2 on a timescale of a few minutes. We find that maintaining NO mixing ratios of, e.g., 40 pptv requires a ground-level NO emission rate of 0.33 pptv s−1 (into a shallow surface layer of 10 m depth). This in turn requires a rapid deposition of NO2 to the surface (vdNO2∼0.15 cm s−1) to reduce nocturnal NO2 levels to match the observations.
Nijing Wang, Lisa Ernle, Gabriel Bekö, Pawel Wargocki, and Jonathan Williams
American Chemical Society (ACS)
Human-emitted volatile organic compounds (VOCs) are mainly from breath and the skin. In this study, we continuously measured VOCs in a stainless-steel environmentally controlled climate chamber (22.5 m3, air change rate at 3.2 h–1) occupied by four seated human volunteers using proton transfer reaction time-of-flight mass spectrometry and gas chromatography mass spectrometry. Experiments with human whole body, breath-only, and dermal-only emissions were performed under ozone-free and ozone-present conditions. In addition, the effect of temperature, relative humidity, clothing type, and age was investigated for whole-body emissions. Without ozone, the whole-body total emission rate (ER) was 2180 ± 620 μg h–1 per person (p–1), dominated by exhaled chemicals. The ERs of oxygenated VOCs were positively correlated with the enthalpy of the air. Under ozone-present conditions (∼37 ppb), the whole-body total ER doubled, with the increase mainly driven by VOCs resulting from skin surface lipids/ozone reactions, which increased with relative humidity. Long clothing (more covered skin) was found to reduce the total ERs but enhanced certain chemicals related to the clothing. The ERs of VOCs derived from this study provide a valuable data set of human emissions under various conditions and can be used in models to better predict indoor air quality, especially for highly occupied environments.
Mitsuharu Sakamoto, Mengze Li, Kazuki Kuga, Kazuhide Ito, Gabriel Bekö, Jonathan Williams, and Pawel Wargocki
Elsevier BV
Christiane Werner, Laura K. Meredith, S. Nemiah Ladd, Johannes Ingrisch, Angelika Kübert, Joost van Haren, Michael Bahn, Kinzie Bailey, Ines Bamberger, Matthias Beyer,et al.
American Association for the Advancement of Science (AAAS)
An experimental forest ecosystem drought Drought is affecting many of the world’ s forested ecosystems, but it has proved challenging to develop an ecosystem-level mechanistic understanding of the ways that drought affects carbon and water fluxes through forest ecosystems. Werner et al . used an experimental approach by imposing an artificial drought on an entire enclosed ecosystem: the Biosphere 2 Tropical Rainforest in Arizona (see the Perspective by Eisenhauer and Weigelt). The authors show that ecosystem-scale plant responses to drought depend on distinct plant functional groups, differing in their water-use strategies and their position in the forest canopy. The balance of these plant functional groups drives changes in carbon and water fluxes, as well as the release of volatile organic compounds into the atmosphere. —AMS