Articles | Volume 17, issue 11
https://doi.org/10.5194/acp-17-6743-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/acp-17-6743-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
08 Jun 2017
Research article |
| 08 Jun 2017
Secondary ozone peaks in the troposphere over the Himalayas
Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
Andrea Pozzer
Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
Dimitris Akritidis
Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
Department of Meteorology and Climatology, School of Geology, Aristotle University of Thessaloniki, Thessaloniki, Greece
Jos Lelieveld
Atmospheric Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
Energy, Environment and Water Research Center, The Cyprus Institute, Nicosia, Cyprus
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Simone T. Andersen, Max R. McGillen, Chaoyang Xue, Tobias Seubert, Patrick Dewald, Gunther N. T. E. Türk, Jan Schuladen, Cyrielle Denjean, Jean-Claude Etienne, Olivier Garrouste, Marina Jamar, Sergio Harb, Manuela Cirtog, Vincent Michoud, Mathieu Cazaunau, Antonin Bergé, Christopher Cantrell, Sebastien Dusanter, Bénédicte Picquet-Varrault, Alexandre Kukui, Abdelwahid Mellouki, Lucy J. Carpenter, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 24, 11603–11618, https://doi.org/10.5194/acp-24-11603-2024, https://doi.org/10.5194/acp-24-11603-2024, 2024
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Using measurements of various trace gases in a suburban forest near Paris in the summer of 2022, we were able to gain insight into the sources and sinks of NOx (NO+NO2) with a special focus on their nighttime chemical and physical loss processes. NO was observed as a result of nighttime soil emissions when O3 levels were strongly depleted by deposition. NO oxidation products were not observed at night, indicating that soil and/or foliar surfaces are an efficient sink of reactive N.
Patrick Dewald, Tobias Seubert, Simone T. Andersen, Gunther N. T. E. Türk, Jan Schuladen, Max R. McGillen, Cyrielle Denjean, Jean-Claude Etienne, Olivier Garrouste, Marina Jamar, Sergio Harb, Manuela Cirtog, Vincent Michoud, Mathieu Cazaunau, Antonin Bergé, Christopher Cantrell, Sebastien Dusanter, Bénédicte Picquet-Varrault, Alexandre Kukui, Chaoyang Xue, Abdelwahid Mellouki, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 24, 8983–8997, https://doi.org/10.5194/acp-24-8983-2024, https://doi.org/10.5194/acp-24-8983-2024, 2024
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In the scope of a field campaign in a suburban forest near Paris in the summer of 2022, we measured the reactivity of the nitrate radical NO3 towards biogenic volatile organic compounds (BVOCs; e.g. monoterpenes) mainly below but also above the canopy. NO3 reactivity was the highest during nights with strong temperature inversions and decreased strongly with height. Reactions with BVOCs were the main removal process of NO3 throughout the diel cycle below the canopy.
Luiz A. T. Machado, Jürgen Kesselmeier, Santiago Botía, Hella van Asperen, Meinrat O. Andreae, Alessandro C. de Araújo, Paulo Artaxo, Achim Edtbauer, Rosaria R. Ferreira, Marco A. Franco, Hartwig Harder, Sam P. Jones, Cléo Q. Dias-Júnior, Guido G. Haytzmann, Carlos A. Quesada, Shujiro Komiya, Jost Lavric, Jos Lelieveld, Ingeborg Levin, Anke Nölscher, Eva Pfannerstill, Mira L. Pöhlker, Ulrich Pöschl, Akima Ringsdorf, Luciana Rizzo, Ana M. Yáñez-Serrano, Susan Trumbore, Wanda I. D. Valenti, Jordi Vila-Guerau de Arellano, David Walter, Jonathan Williams, Stefan Wolff, and Christopher Pöhlker
Atmos. Chem. Phys., 24, 8893–8910, https://doi.org/10.5194/acp-24-8893-2024, https://doi.org/10.5194/acp-24-8893-2024, 2024
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Composite analysis of gas concentration before and after rainfall, during the day and night, gives insight into the complex relationship between trace gas variability and precipitation. The analysis helps us to understand the sources and sinks of trace gases within a forest ecosystem. It elucidates processes that are not discernible under undisturbed conditions and contributes to a deeper understanding of the trace gas life cycle and its intricate interactions with cloud dynamics in the Amazon.
Pantelis Georgiades, Matthias Kohl, Mihalis A. Nicolaou, Theodoros Christoudias, Andrea Pozzer, Constantine Dovrolis, and Jos Lelieveld
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-314, https://doi.org/10.5194/essd-2024-314, 2024
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This study maps global ultrafine particle (UFP) concentrations, pollutants known to affect health, using machine learning. By combining environmental and urban data, we predicted UFP levels at a fine 1 km resolution, highlighting areas of high exposure. Our results provide data for public health policies aimed at reducing air pollution impacts. This research bridges data gaps, offering a valuable tool for understanding and mitigating the health effects of UFP exposure.
Anna Martin, Veronika Gayler, Benedikt Steil, Klaus Klingmüller, Patrick Jöckel, Holger Tost, Jos Lelieveld, and Andrea Pozzer
Geosci. Model Dev., 17, 5705–5732, https://doi.org/10.5194/gmd-17-5705-2024, https://doi.org/10.5194/gmd-17-5705-2024, 2024
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The study evaluates the land surface and vegetation model JSBACHv4 as a replacement for the simplified submodel SURFACE in EMAC. JSBACH mitigates earlier problems of soil dryness, which are critical for vegetation modelling. When analysed using different datasets, the coupled model shows strong correlations of key variables, such as land surface temperature, surface albedo and radiation flux. The versatility of the model increases significantly, while the overall performance does not degrade.
Alkiviadis Kalisoras, Aristeidis K. Georgoulias, Dimitris Akritidis, Robert J. Allen, Vaishali Naik, Chaincy Kuo, Sophie Szopa, Pierre Nabat, Dirk Olivié, Twan van Noije, Philippe Le Sager, David Neubauer, Naga Oshima, Jane Mulcahy, Larry W. Horowitz, and Prodromos Zanis
Atmos. Chem. Phys., 24, 7837–7872, https://doi.org/10.5194/acp-24-7837-2024, https://doi.org/10.5194/acp-24-7837-2024, 2024
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Effective radiative forcing (ERF) is a metric for estimating how human activities and natural agents change the energy flow into and out of the Earth’s climate system. We investigate the anthropogenic aerosol ERF, and we estimate the contribution of individual processes to the total ERF using simulations from Earth system models within the Coupled Model Intercomparison Project Phase 6 (CMIP6). Our findings highlight that aerosol–cloud interactions drive ERF variability during the last 150 years.
Georgia Lazoglou, Theo Economou, Christina Anagnostopoulou, George Zittis, Anna Tzyrkalli, Pantelis Georgiades, and Jos Lelieveld
Geosci. Model Dev., 17, 4689–4703, https://doi.org/10.5194/gmd-17-4689-2024, https://doi.org/10.5194/gmd-17-4689-2024, 2024
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This study focuses on the important issue of the drizzle bias effect in regional climate models, described by an over-prediction of the number of rainy days while underestimating associated precipitation amounts. For this purpose, two distinct methodologies are applied and rigorously evaluated. These results are encouraging for using the multivariate machine learning method random forest to increase the accuracy of climate models concerning the projection of the number of wet days.
Linda Ort, Lenard Lukas Röder, Uwe Parchatka, Rainer Königstedt, Daniel Crowley, Frank Kunz, Ralf Wittkowski, Jos Lelieveld, and Horst Fischer
Atmos. Meas. Tech., 17, 3553–3565, https://doi.org/10.5194/amt-17-3553-2024, https://doi.org/10.5194/amt-17-3553-2024, 2024
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Airborne in situ measurements are of great importance to collect valuable data to improve our knowledge of the atmosphere but also present challenges which demand specific designs. This study presents an IR spectrometer for airborne trace-gas measurements with high data efficiency and a simple, compact design. Its in-flight performance is characterized with the help of a test flight and a comparison with another spectrometer. Moreover, results from its first campaign highlight its benefits.
Simone Rodrigues, Glauber Cirino, Demerval Moreira, Andrea Pozzer, Rafael Palácios, Sung-Ching Lee, Breno Imbiriba, José Nogueira, Maria Isabel Vitorino, and George Vourlitis
Biogeosciences, 21, 843–868, https://doi.org/10.5194/bg-21-843-2024, https://doi.org/10.5194/bg-21-843-2024, 2024
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The radiative effects of atmospheric particles are still unknown for a wide variety of species and types of vegetation present in Amazonian biomes. We examined the effects of aerosols on solar radiation and their impacts on photosynthesis in an area of semideciduous forest in the southern Amazon Basin. Under highly smoky-sky conditions, our results show substantial photosynthetic interruption (20–70 %), attributed specifically to the decrease in solar radiation and leaf canopy temperature.
Imran A. Girach, Narendra Ojha, Prabha R. Nair, Kandula V. Subrahmanyam, Neelakantan Koushik, Mohammed M. Nazeer, Nadimpally Kiran Kumar, Surendran Nair Suresh Babu, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 24, 1979–1995, https://doi.org/10.5194/acp-24-1979-2024, https://doi.org/10.5194/acp-24-1979-2024, 2024
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We investigate surface ozone variability in East Antarctica based on measurements and EMAC global model simulations during austral summer. Nearly half of the surface ozone is found to be of stratospheric origin. The east coast of Antarctica acts as a stronger sink of ozone than surrounding regions. Photochemical loss of ozone is counterbalanced by downward transport of ozone. The study highlights the intertwined role of chemistry and dynamics in governing ozone variations over East Antarctica.
Leon Kuhn, Steffen Beirle, Vinod Kumar, Sergey Osipov, Andrea Pozzer, Tim Bösch, Rajesh Kumar, and Thomas Wagner
Atmos. Chem. Phys., 24, 185–217, https://doi.org/10.5194/acp-24-185-2024, https://doi.org/10.5194/acp-24-185-2024, 2024
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NO₂ is an important air pollutant. It was observed that the WRF-Chem model shows significant deviations in NO₂ abundance when compared to measurements. We use a 1-month simulation over central Europe to show that these deviations can be mostly resolved by reparameterization of the vertical mixing routine. In order to validate our results, they are compared to in situ, satellite, and MAX-DOAS measurements.
Meghna Soni, Rolf Sander, Lokesh K. Sahu, Domenico Taraborrelli, Pengfei Liu, Ankit Patel, Imran A. Girach, Andrea Pozzer, Sachin S. Gunthe, and Narendra Ojha
Atmos. Chem. Phys., 23, 15165–15180, https://doi.org/10.5194/acp-23-15165-2023, https://doi.org/10.5194/acp-23-15165-2023, 2023
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The study presents the implementation of comprehensive multiphase chlorine chemistry in the box model CAABA/MECCA. Simulations for contrasting urban environments of Asia and Europe highlight the significant impacts of chlorine on atmospheric oxidation capacity and composition. Chemical processes governing the production and loss of chlorine-containing species has been discussed. The updated chemical mechanism will be useful to interpret field measurements and for future air quality studies.
Ryan Vella, Andrea Pozzer, Matthew Forrest, Jos Lelieveld, Thomas Hickler, and Holger Tost
Biogeosciences, 20, 4391–4412, https://doi.org/10.5194/bg-20-4391-2023, https://doi.org/10.5194/bg-20-4391-2023, 2023
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We investigated the effect of the El Niño–Southern Oscillation (ENSO) on biogenic volatile organic compound (BVOC) emissions from plants. ENSO events can cause a significant increase in these emissions, which have a long-term impact on the Earth's atmosphere. Persistent ENSO conditions can cause long-term changes in vegetation, resulting in even higher BVOC emissions. We link ENSO-induced emission anomalies with driving atmospheric and vegetational variables.
Susanna Strada, Andrea Pozzer, Graziano Giuliani, Erika Coppola, Fabien Solmon, Xiaoyan Jiang, Alex Guenther, Efstratios Bourtsoukidis, Dominique Serça, Jonathan Williams, and Filippo Giorgi
Atmos. Chem. Phys., 23, 13301–13327, https://doi.org/10.5194/acp-23-13301-2023, https://doi.org/10.5194/acp-23-13301-2023, 2023
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Water deficit modifies emissions of isoprene, an aromatic compound released by plants that influences the production of an air pollutant such as ozone. Numerical modelling shows that, during the warmest and driest summers, isoprene decreases between −20 and −60 % over the Euro-Mediterranean region, while near-surface ozone only diminishes by a few percent. Decreases in isoprene emissions not only happen under dry conditions, but also could occur after prolonged or repeated water deficits.
Zaneta Hamryszczak, Antonia Hartmann, Dirk Dienhart, Sascha Hafermann, Bettina Brendel, Rainer Königstedt, Uwe Parchatka, Jos Lelieveld, and Horst Fischer
Atmos. Meas. Tech., 16, 4741–4756, https://doi.org/10.5194/amt-16-4741-2023, https://doi.org/10.5194/amt-16-4741-2023, 2023
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Hydroperoxide measurements improve the understanding of atmospheric oxidation processes. We introduce an instrumental setup for airborne measurements. The aim of the work is the characterization of the measurement method with emphasis on interferences impacting instrumental uncertainty. Technical and physical challenges do not critically impact the instrumental performance. The instrument resolves dynamic processes, such as convective transport, as shown based on the CAFE-Brazil campaign.
Matthias Kohl, Jos Lelieveld, Sourangsu Chowdhury, Sebastian Ehrhart, Disha Sharma, Yafang Cheng, Sachchida Nand Tripathi, Mathew Sebastian, Govindan Pandithurai, Hongli Wang, and Andrea Pozzer
Atmos. Chem. Phys., 23, 13191–13215, https://doi.org/10.5194/acp-23-13191-2023, https://doi.org/10.5194/acp-23-13191-2023, 2023
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Knowledge on atmospheric ultrafine particles (UFPs) with a diameter smaller than 100 nm is crucial for public health and the hydrological cycle. We present a new global dataset of UFP concentrations at the Earth's surface derived with a comprehensive chemistry–climate model and evaluated with ground-based observations. The evaluation results are combined with high-resolution primary emissions to downscale UFP concentrations to an unprecedented horizontal resolution of 0.1° × 0.1°.
Clara M. Nussbaumer, Horst Fischer, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 23, 12651–12669, https://doi.org/10.5194/acp-23-12651-2023, https://doi.org/10.5194/acp-23-12651-2023, 2023
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Ozone is a greenhouse gas and contributes to the earth’s radiative energy budget and therefore to global warming. This effect is the largest in the upper troposphere. In this study, we investigate the processes controlling ozone formation and the sensitivity to its precursors in the upper tropical troposphere based on model simulations by the ECHAM5/MESSy2 Atmospheric Chemistry (EMAC) model. We find that NO𝑥 emissions from lightning most importantly affect ozone chemistry at these altitudes.
Seyed Omid Nabavi, Theodoros Christoudias, Yiannis Proestos, Christos Fountoukis, Huda Al-Sulaiti, and Jos Lelieveld
Atmos. Chem. Phys., 23, 7719–7739, https://doi.org/10.5194/acp-23-7719-2023, https://doi.org/10.5194/acp-23-7719-2023, 2023
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The objective of our study is to comprehensively assess the timing of radioactive material transportation and deposition, along with the associated population exposure in the designated region. We employed diverse meteorological inputs, emission specifics, and simulation codes, aiming to quantify the level of uncertainty.
Klaus Klingmüller and Jos Lelieveld
Geosci. Model Dev., 16, 3013–3028, https://doi.org/10.5194/gmd-16-3013-2023, https://doi.org/10.5194/gmd-16-3013-2023, 2023
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Desert dust has significant impacts on climate, public health, infrastructure and ecosystems. An impact assessment requires numerical predictions, which are challenging because the dust emissions are not well known. We present a novel approach using satellite observations and machine learning to more accurately estimate the emissions and to improve the model simulations.
Zaneta Hamryszczak, Dirk Dienhart, Bettina Brendel, Roland Rohloff, Daniel Marno, Monica Martinez, Hartwig Harder, Andrea Pozzer, Birger Bohn, Martin Zöger, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 23, 5929–5943, https://doi.org/10.5194/acp-23-5929-2023, https://doi.org/10.5194/acp-23-5929-2023, 2023
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Hydrogen peroxide is a key contributor to the oxidative chemistry of the atmosphere through its link to the most prominent oxidants controlling its self-cleansing capacity, HOx. During the CAFE-Africa campaign, H2O2 was measured over the Atlantic Ocean and western Africa in August/September 2018. The study gives an overview of the distribution of H2O2 in the upper tropical troposphere and investigates the impact of convective processes in the Intertropical Convergence Zone on the budget of H2O2.
Lenard L. Röder, Patrick Dewald, Clara M. Nussbaumer, Jan Schuladen, John N. Crowley, Jos Lelieveld, and Horst Fischer
Atmos. Meas. Tech., 16, 1167–1178, https://doi.org/10.5194/amt-16-1167-2023, https://doi.org/10.5194/amt-16-1167-2023, 2023
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Field experiments in atmospheric chemistry provide insights into chemical interactions of our atmosphere. However, high data coverage and accuracy are needed to enable further analysis. In this study, we explore a statistical method that combines knowledge about the chemical reactions with information from measurements to increase the quality of field experiment datasets. We test the algorithm for several applications and discuss limitations that depend on the specific variable and the dynamics.
Ryan Vella, Matthew Forrest, Jos Lelieveld, and Holger Tost
Geosci. Model Dev., 16, 885–906, https://doi.org/10.5194/gmd-16-885-2023, https://doi.org/10.5194/gmd-16-885-2023, 2023
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Biogenic volatile organic compounds (BVOCs) are released by vegetation and have a major impact on atmospheric chemistry and aerosol formation. Non-interacting vegetation constrains the majority of numerical models used to estimate global BVOC emissions, and thus, the effects of changing vegetation on emissions are not addressed. In this work, we replace the offline vegetation with dynamic vegetation states by linking a chemistry–climate model with a global dynamic vegetation model.
Jennifer Schallock, Christoph Brühl, Christine Bingen, Michael Höpfner, Landon Rieger, and Jos Lelieveld
Atmos. Chem. Phys., 23, 1169–1207, https://doi.org/10.5194/acp-23-1169-2023, https://doi.org/10.5194/acp-23-1169-2023, 2023
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We characterized the influence of volcanic aerosols for the period 1990–2019 and established a volcanic SO2 emission inventory that includes more than 500 eruptions. From limb-based satellite observations of SO2 and extinction, we derive 3D plumes of SO2 perturbations and injected mass by a novel method. We calculate instantaneous radiative forcing with a comprehensive chemisty climate model. Our results show that smaller eruptions can also contribute to the stratospheric aerosol forcing.
Mohamed Abdelkader, Georgiy Stenchikov, Andrea Pozzer, Holger Tost, and Jos Lelieveld
Atmos. Chem. Phys., 23, 471–500, https://doi.org/10.5194/acp-23-471-2023, https://doi.org/10.5194/acp-23-471-2023, 2023
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We study the effect of injected volcanic ash, water vapor, and SO2 on the development of the volcanic cloud and the stratospheric aerosol optical depth (AOD). Both are sensitive to the initial injection height and to the aging of the volcanic ash shaped by heterogeneous chemistry coupled with the ozone cycle. The paper explains the large differences in AOD for different injection scenarios, which could improve the estimate of the radiative forcing of volcanic eruptions.
Dirk Dienhart, Bettina Brendel, John N. Crowley, Philipp G. Eger, Hartwig Harder, Monica Martinez, Andrea Pozzer, Roland Rohloff, Jan Schuladen, Sebastian Tauer, David Walter, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 23, 119–142, https://doi.org/10.5194/acp-23-119-2023, https://doi.org/10.5194/acp-23-119-2023, 2023
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Formaldehyde and hydroperoxide measurements were performed in the marine boundary layer around the Arabian Peninsula and highlight the Suez Canal and Arabian (Persian) Gulf as a hotspot of photochemical air pollution. A comparison with the EMAC model shows that the formaldehyde results match within a factor of 2, while hydrogen peroxide was overestimated by more than a factor of 5, which revealed enhanced HOx (OH+HO2) radicals in the simulation and an underestimation of dry deposition velocites.
Laura Tomsche, Andreas Marsing, Tina Jurkat-Witschas, Johannes Lucke, Stefan Kaufmann, Katharina Kaiser, Johannes Schneider, Monika Scheibe, Hans Schlager, Lenard Röder, Horst Fischer, Florian Obersteiner, Andreas Zahn, Martin Zöger, Jos Lelieveld, and Christiane Voigt
Atmos. Chem. Phys., 22, 15135–15151, https://doi.org/10.5194/acp-22-15135-2022, https://doi.org/10.5194/acp-22-15135-2022, 2022
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The detection of sulfur compounds in the upper troposphere (UT) and lower stratosphere (LS) is a challenge. In-flight measurements of SO2 and sulfate aerosol were performed during the BLUESKY mission in spring 2020 under exceptional atmospheric conditions. Reduced sinks in the dry UTLS and lower but still significant air traffic influenced the enhanced SO2 in the UT, and aged volcanic plumes enhanced the LS sulfate aerosol impacting the atmospheric radiation budget and global climate.
Charlotte M. Beall, Thomas C. J. Hill, Paul J. DeMott, Tobias Köneman, Michael Pikridas, Frank Drewnick, Hartwig Harder, Christopher Pöhlker, Jos Lelieveld, Bettina Weber, Minas Iakovides, Roman Prokeš, Jean Sciare, Meinrat O. Andreae, M. Dale Stokes, and Kimberly A. Prather
Atmos. Chem. Phys., 22, 12607–12627, https://doi.org/10.5194/acp-22-12607-2022, https://doi.org/10.5194/acp-22-12607-2022, 2022
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Ice-nucleating particles (INPs) are rare aerosols that can trigger ice formation in clouds and affect climate-relevant cloud properties such as phase, reflectivity and lifetime. Dust is the dominant INP source, yet few measurements have been reported near major dust sources. We report INP observations within hundreds of kilometers of the biggest dust source regions globally: the Sahara and the Arabian Peninsula. Results show that at temperatures > −15 °C, INPs are dominated by organics.
Mengze Li, Andrea Pozzer, Jos Lelieveld, and Jonathan Williams
Earth Syst. Sci. Data, 14, 4351–4364, https://doi.org/10.5194/essd-14-4351-2022, https://doi.org/10.5194/essd-14-4351-2022, 2022
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We present a northern hemispheric airborne measurement dataset of atmospheric ethane, propane and methane and temporal trends for the time period 2006–2016 in the upper troposphere and lower stratosphere. The growth rates of ethane, methane, and propane in the upper troposphere are -2.24, 0.33, and -0.78 % yr-1, respectively, and in the lower stratosphere they are -3.27, 0.26, and -4.91 % yr-1, respectively, in 2006–2016.
Simon F. Reifenberg, Anna Martin, Matthias Kohl, Sara Bacer, Zaneta Hamryszczak, Ivan Tadic, Lenard Röder, Daniel J. Crowley, Horst Fischer, Katharina Kaiser, Johannes Schneider, Raphael Dörich, John N. Crowley, Laura Tomsche, Andreas Marsing, Christiane Voigt, Andreas Zahn, Christopher Pöhlker, Bruna A. Holanda, Ovid Krüger, Ulrich Pöschl, Mira Pöhlker, Patrick Jöckel, Marcel Dorf, Ulrich Schumann, Jonathan Williams, Birger Bohn, Joachim Curtius, Hardwig Harder, Hans Schlager, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 22, 10901–10917, https://doi.org/10.5194/acp-22-10901-2022, https://doi.org/10.5194/acp-22-10901-2022, 2022
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In this work we use a combination of observational data from an aircraft campaign and model results to investigate the effect of the European lockdown due to COVID-19 in spring 2020. Using model results, we show that the largest relative changes to the atmospheric composition caused by the reduced emissions are located in the upper troposphere around aircraft cruise altitude, while the largest absolute changes are present at the surface.
Zaneta T. Hamryszczak, Andrea Pozzer, Florian Obersteiner, Birger Bohn, Benedikt Steil, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 22, 9483–9497, https://doi.org/10.5194/acp-22-9483-2022, https://doi.org/10.5194/acp-22-9483-2022, 2022
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Hydrogen peroxide plays a pivotal role in the chemistry of the atmosphere. Together with organic hydroperoxides, it forms a reservoir for peroxy radicals, which are known to be the key contributors to the self-cleaning processes of the atmosphere. Hydroperoxides were measured over Europe during the BLUESKY campaign in May–June 2020. The paper gives an overview of the distribution of the species in the troposphere and investigates the impact of wet scavenging and deposition on the budget of H2O2.
Marco Wietzoreck, Marios Kyprianou, Benjamin A. Musa Bandowe, Siddika Celik, John N. Crowley, Frank Drewnick, Philipp Eger, Nils Friedrich, Minas Iakovides, Petr Kukučka, Jan Kuta, Barbora Nežiková, Petra Pokorná, Petra Přibylová, Roman Prokeš, Roland Rohloff, Ivan Tadic, Sebastian Tauer, Jake Wilson, Hartwig Harder, Jos Lelieveld, Ulrich Pöschl, Euripides G. Stephanou, and Gerhard Lammel
Atmos. Chem. Phys., 22, 8739–8766, https://doi.org/10.5194/acp-22-8739-2022, https://doi.org/10.5194/acp-22-8739-2022, 2022
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A unique dataset of concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) and their alkylated, oxygenated and nitrated derivatives, in total 74 individual species, in the marine atmosphere is presented. Exposure to these substances poses a major health risk. We found very low concentrations over the Arabian Sea, while both local and long-range-transported pollution caused elevated levels over the Mediterranean Sea and the Arabian Gulf.
Ovid O. Krüger, Bruna A. Holanda, Sourangsu Chowdhury, Andrea Pozzer, David Walter, Christopher Pöhlker, Maria Dolores Andrés Hernández, John P. Burrows, Christiane Voigt, Jos Lelieveld, Johannes Quaas, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 22, 8683–8699, https://doi.org/10.5194/acp-22-8683-2022, https://doi.org/10.5194/acp-22-8683-2022, 2022
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The abrupt reduction in human activities during the first COVID-19 lockdown created unprecedented atmospheric conditions. We took the opportunity to quantify changes in black carbon (BC) as a major anthropogenic air pollutant. Therefore, we measured BC on board a research aircraft over Europe during the lockdown and compared the results to measurements from 2017. With model simulations we account for different weather conditions and find a lockdown-related decrease in BC of 41 %.
Patrick Dewald, Clara M. Nussbaumer, Jan Schuladen, Akima Ringsdorf, Achim Edtbauer, Horst Fischer, Jonathan Williams, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 22, 7051–7069, https://doi.org/10.5194/acp-22-7051-2022, https://doi.org/10.5194/acp-22-7051-2022, 2022
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We measured the gas-phase reactivity of the NO3 radical on the summit (825 m a.s.l.) of a semi-rural mountain in southwestern Germany in July 2021. The impact of VOC-induced NO3 losses (mostly monoterpenes) competing with a loss by reaction with NO and photolysis throughout the diel cycle was estimated. Besides chemistry, boundary layer dynamics and plant-physiological processes presumably have a great impact on our observations, which were compared to previous NO3 measurements at the same site.
George K. Georgiou, Theodoros Christoudias, Yiannis Proestos, Jonilda Kushta, Michael Pikridas, Jean Sciare, Chrysanthos Savvides, and Jos Lelieveld
Geosci. Model Dev., 15, 4129–4146, https://doi.org/10.5194/gmd-15-4129-2022, https://doi.org/10.5194/gmd-15-4129-2022, 2022
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We evaluate the skill of the WRF-Chem model to perform high-resolution air quality forecasts (including ozone, nitrogen dioxide, and fine particulate matter) over the Eastern Mediterranean, during winter and summer. We compare the forecast output to observational data from background and urban locations and the forecast output from CAMS. WRF-Chem was found to forecast the concentrations and diurnal profiles of gas-phase pollutants in urban areas with higher accuracy.
Dimitris Akritidis, Andrea Pozzer, Johannes Flemming, Antje Inness, Philippe Nédélec, and Prodromos Zanis
Atmos. Chem. Phys., 22, 6275–6289, https://doi.org/10.5194/acp-22-6275-2022, https://doi.org/10.5194/acp-22-6275-2022, 2022
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We perform a process-oriented evaluation of Copernicus Atmosphere Monitoring Service (CAMS) reanalysis (CAMSRA) O3 over Europe using WOUDC (World Ozone and Ultraviolet Radiation Data Centre) ozonesondes and IAGOS (In-service Aircraft for a Global Observing System) aircraft measurements. Chemical data assimilation assists CAMSRA to reproduce the observed O3 increases in the troposphere during the examined folding events, but it mostly results in O3 overestimation in the upper troposphere.
Clara M. Nussbaumer, Andrea Pozzer, Ivan Tadic, Lenard Röder, Florian Obersteiner, Hartwig Harder, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 22, 6151–6165, https://doi.org/10.5194/acp-22-6151-2022, https://doi.org/10.5194/acp-22-6151-2022, 2022
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The European COVID-19 lockdowns have significantly reduced the emission of primary pollutants such as NOx, which impacts the tropospheric photochemical processes and the abundance of O3. In this study, we present how the lockdowns have affected tropospheric trace gases and ozone production based on in situ observations and modeling simulations. We additionally show that the chemical regime shifted from a transition point to a NOx limitation in the upper troposphere.
Wenyu Sun, Matias Berasategui, Andrea Pozzer, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 22, 4969–4984, https://doi.org/10.5194/acp-22-4969-2022, https://doi.org/10.5194/acp-22-4969-2022, 2022
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The reaction between OH and SO2 is a termolecular process that in the atmosphere results in the formation of H2SO4 and thus aerosols. We present the first temperature- and pressure-dependent measurements of the rate coefficients in N2. This is also the first study to examine the effects of water vapour on the kinetics of this reaction. Our results indicate the rate coefficient is larger than that recommended by evaluation panels, with deviations of up to 30 % in some parts of the atmosphere.
Andrea Pozzer, Simon F. Reifenberg, Vinod Kumar, Bruno Franco, Matthias Kohl, Domenico Taraborrelli, Sergey Gromov, Sebastian Ehrhart, Patrick Jöckel, Rolf Sander, Veronica Fall, Simon Rosanka, Vlassis Karydis, Dimitris Akritidis, Tamara Emmerichs, Monica Crippa, Diego Guizzardi, Johannes W. Kaiser, Lieven Clarisse, Astrid Kiendler-Scharr, Holger Tost, and Alexandra Tsimpidi
Geosci. Model Dev., 15, 2673–2710, https://doi.org/10.5194/gmd-15-2673-2022, https://doi.org/10.5194/gmd-15-2673-2022, 2022
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A newly developed setup of the chemistry general circulation model EMAC (ECHAM5/MESSy for Atmospheric Chemistry) is evaluated here. A comprehensive organic degradation mechanism is used and coupled with a volatility base model.
The results show that the model reproduces most of the tracers and aerosols satisfactorily but shows discrepancies for oxygenated organic gases. It is also shown that this model configuration can be used for further research in atmospheric chemistry.
Guangjie Zheng, Hang Su, Siwen Wang, Andrea Pozzer, and Yafang Cheng
Atmos. Chem. Phys., 22, 47–63, https://doi.org/10.5194/acp-22-47-2022, https://doi.org/10.5194/acp-22-47-2022, 2022
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The recently proposed multiphase buffer theory provides a framework to reconstruct long-term trends and spatial variations in aerosol pH, while non-ideality is a major limitation for its broad applications. Here we proposed a parameterization method to estimate the impact of non-ideality and validated it against long-term observations and global simulations. With this method, the multiphase buffer theory can reproduce well aerosol pH variations estimated by comprehensive thermodynamic models.
Clara M. Nussbaumer, John N. Crowley, Jan Schuladen, Jonathan Williams, Sascha Hafermann, Andreas Reiffs, Raoul Axinte, Hartwig Harder, Cheryl Ernest, Anna Novelli, Katrin Sala, Monica Martinez, Chinmay Mallik, Laura Tomsche, Christian Plass-Dülmer, Birger Bohn, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 21, 18413–18432, https://doi.org/10.5194/acp-21-18413-2021, https://doi.org/10.5194/acp-21-18413-2021, 2021
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HCHO is an important atmospheric trace gas influencing the photochemical processes in the Earth’s atmosphere, including the budget of HOx and the abundance of tropospheric O3. This research presents the photochemical calculations of HCHO and O3 based on three field campaigns across Europe. We show that HCHO production via the oxidation of only four volatile organic compound precursors, i.e., CH4, CH3CHO, C5H8 and CH3OH, can balance the observed loss at all sites well.
Dirk Dienhart, John N. Crowley, Efstratios Bourtsoukidis, Achim Edtbauer, Philipp G. Eger, Lisa Ernle, Hartwig Harder, Bettina Hottmann, Monica Martinez, Uwe Parchatka, Jean-Daniel Paris, Eva Y. Pfannerstill, Roland Rohloff, Jan Schuladen, Christof Stönner, Ivan Tadic, Sebastian Tauer, Nijing Wang, Jonathan Williams, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 21, 17373–17388, https://doi.org/10.5194/acp-21-17373-2021, https://doi.org/10.5194/acp-21-17373-2021, 2021
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We present the first ship-based in situ measurements of formaldehyde (HCHO), hydroxyl radicals (OH) and the OH reactivity around the Arabian Peninsula. Regression analysis of the HCHO production rate and the related OH chemistry revealed the regional HCHO yield αeff, which represents the different chemical regimes encountered. Highest values were found for the Arabian Gulf (also known as the Persian Gulf), which highlights this region as a hotspot of photochemical air pollution.
Clara M. Nussbaumer, Uwe Parchatka, Ivan Tadic, Birger Bohn, Daniel Marno, Monica Martinez, Roland Rohloff, Hartwig Harder, Flora Kluge, Klaus Pfeilsticker, Florian Obersteiner, Martin Zöger, Raphael Doerich, John N. Crowley, Jos Lelieveld, and Horst Fischer
Atmos. Meas. Tech., 14, 6759–6776, https://doi.org/10.5194/amt-14-6759-2021, https://doi.org/10.5194/amt-14-6759-2021, 2021
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NO2 plays a central role in atmospheric photochemical processes and requires accurate measurements. This research presents NO2 data obtained via chemiluminescence using a photolytic converter from airborne studies around Cabo Verde and laboratory investigations. We show the limits and error-proneness of a conventional blue light converter in aircraft measurements affected by humidity and NO levels and suggest the use of an alternative quartz converter for more reliable results.
Vlassis A. Karydis, Alexandra P. Tsimpidi, Andrea Pozzer, and Jos Lelieveld
Atmos. Chem. Phys., 21, 14983–15001, https://doi.org/10.5194/acp-21-14983-2021, https://doi.org/10.5194/acp-21-14983-2021, 2021
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Aerosol particle pH is well-buffered by alkaline compounds, notably NH3 and crustal elements. NH3 is found to supply remarkable buffering capacity on a global scale, from the polluted continents to the remote oceans. Potential future changes in agricultural NH3 must be accompanied by strong reductions of SO2 and NOx to avoid particles becoming highly acidic, with implications for human health (aerosol toxicity), ecosystems (acid deposition), clouds, and climate (aerosol hygroscopicity).
Andrea Pozzer
Geosci. Commun., 4, 453–460, https://doi.org/10.5194/gc-4-453-2021, https://doi.org/10.5194/gc-4-453-2021, 2021
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In this paper we investigate the numbers of pages, references and references per page in open-access EGU journals. We showed that, while the number of references and number of pages have been constantly increasing in the period 2010–2020, the number of references per page did not change in the same period. Furthermore, all the journals showed a similar number of references per page, i.e. ~ 3.8 references per page.
Philipp G. Eger, Luc Vereecken, Rolf Sander, Jan Schuladen, Nicolas Sobanski, Horst Fischer, Einar Karu, Jonathan Williams, Ville Vakkari, Tuukka Petäjä, Jos Lelieveld, Andrea Pozzer, and John N. Crowley
Atmos. Chem. Phys., 21, 14333–14349, https://doi.org/10.5194/acp-21-14333-2021, https://doi.org/10.5194/acp-21-14333-2021, 2021
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We determine the impact of pyruvic acid photolysis on the formation of acetaldehyde and peroxy radicals during summer and autumn in the Finnish boreal forest using a data-constrained box model. Our results are dependent on the chosen scenario in which the overall quantum yield and the photolysis products are varied. We highlight that pyruvic acid photolysis can be an important contributor to acetaldehyde and peroxy radical formation in remote, forested regions.
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Short summary
We investigate the processes, frequency of occurrence and seasonality, and effects of strongly enhanced ozone layers in the middle–upper troposphere (SOPs) over the Himalayas using a global model (EMAC). Rapid transport of stratospheric air masses is found as a key underlying process. Model predicts more frequent SOP events during the pre-monsoon. SOPs are found to significantly enhance the tropospheric ozone column over the Himalayas.
We investigate the processes, frequency of occurrence and seasonality, and effects of strongly...
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