Articles | Volume 22, issue 11
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Contribution of Asian emissions to upper tropospheric CO over the remote Pacific
Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany
Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany
No articles found.
Frederik Harzer, Hella Garny, Felix Ploeger, Harald Bönisch, Peter Hoor, and Thomas Birner
Atmos. Chem. Phys., 23, 10661–10675,Short summary
We study the statistical relation between year-by-year fluctuations in winter-mean ozone and the strength of the stratospheric polar vortex. In the latitude–pressure plane, regression analysis shows that anomalously weak polar vortex years are associated with three pronounced local ozone maxima over the polar cap relative to the winter climatology. These response maxima primarily reflect the non-trivial combination of different ozone transport processes with varying relative contributions.
Tanja J. Schuck, Johannes Degen, Eric Hintsa, Peter Hoor, Markus Jesswein, Timo Keber, Daniel Kunkel, Fred Moore, Florian Obersteiner, Matt Rigby, Thomas Wagenhäuser, Luke M. Western, Andreas Zahn, and Andreas Engel
We study the interhemispheric gradient of sulfur hexafluoride (SF6), a strong long-lived greenhouse gas. Its emissions are stronger in the northern hemisphere, therefore mixing ratios in the southern hemisphere lag behind. Comparing the observations to results from a box model, the model predicts air in the southern hemisphere to be older. For a better agreement, the emissions used as model input need to be increased, their spatial pattern changed, and we need to modify north-south transport.
Luis F. Millán, Gloria L. Manney, Harald Boenisch, Michaela I. Hegglin, Peter Hoor, Daniel Kunkel, Thierry Leblanc, Irina Petropavlovskikh, Kaley Walker, Krzysztof Wargan, and Andreas Zahn
Atmos. Meas. Tech., 16, 2957–2988,Short summary
The determination of atmospheric composition trends in the upper troposphere and lower stratosphere (UTLS) is still highly uncertain. We present the creation of dynamical diagnostics to map several ozone datasets (ozonesondes, lidars, aircraft, and satellite measurements) in geophysically based coordinate systems. The diagnostics can also be used to analyze other greenhouse gases relevant to surface climate and UTLS chemistry.
Hans-Christoph Lachnitt, Peter Hoor, Daniel Kunkel, Martina Bramberger, Andreas Dörnbrack, Stefan Müller, Philipp Reutter, Andreas Giez, Thorsten Kaluza, and Markus Rapp
Atmos. Chem. Phys., 23, 355–373,Short summary
We present an analysis of high-resolution airborne measurements during a flight of the DEEPWAVE 2014 campaign in New Zealand. The focus of this flight was to study the effects of enhanced mountain wave activity over the Southern Alps. We discuss changes in the upstream and downstream distributions of N2O and CO and show that these changes are related to turbulence-induced trace gas fluxes which have persistent effects on the trace gas composition in the lower stratosphere.
Paul Konopka, Mengchu Tao, Marc von Hobe, Lars Hoffmann, Corinna Kloss, Fabrizio Ravegnani, C. Michael Volk, Valentin Lauther, Andreas Zahn, Peter Hoor, and Felix Ploeger
Geosci. Model Dev., 15, 7471–7487,Short summary
Pure trajectory-based transport models driven by meteorology derived from reanalysis products (ERA5) take into account only the resolved, advective part of transport. That means neither mixing processes nor unresolved subgrid-scale advective processes like convection are included. The Chemical Lagrangian Model of the Stratosphere (CLaMS) includes these processes. We show that isentropic mixing dominates unresolved transport. The second most important transport process is unresolved convection.
Helmut Ziereis, Peter Hoor, Jens-Uwe Grooß, Andreas Zahn, Greta Stratmann, Paul Stock, Michael Lichtenstern, Jens Krause, Vera Bense, Armin Afchine, Christian Rolf, Wolfgang Woiwode, Marleen Braun, Jörn Ungermann, Andreas Marsing, Christiane Voigt, Andreas Engel, Björn-Martin Sinnhuber, and Hermann Oelhaf
Atmos. Chem. Phys., 22, 3631–3654,Short summary
Airborne observations were conducted in the lowermost Arctic stratosphere during the winter of 2015/2016. The observed distribution of reactive nitrogen shows clear indications of nitrification in mid-winter and denitrification in late winter. This was caused by the formation of polar stratospheric cloud particles, which were observed during several flights. The sedimentation and evaporation of these particles and the descent of air masses cause a redistribution of reactive nitrogen.
Valentin Lauther, Bärbel Vogel, Johannes Wintel, Andrea Rau, Peter Hoor, Vera Bense, Rolf Müller, and C. Michael Volk
Atmos. Chem. Phys., 22, 2049–2077,Short summary
We show airborne in situ measurements of the very short-lived ozone-depleting substances CH2Cl2 and CHCl3, revealing particularly high concentrations of both species in the lower stratosphere. Back-trajectory calculations and 3D model simulations show that the air masses with high concentrations originated in the Asian boundary layer and were transported via the Asian summer monsoon. We also identify a fast transport pathway into the stratosphere via the North American monsoon and by hurricanes.
Markus Jesswein, Heiko Bozem, Hans-Christoph Lachnitt, Peter Hoor, Thomas Wagenhäuser, Timo Keber, Tanja Schuck, and Andreas Engel
Atmos. Chem. Phys., 21, 17225–17241,Short summary
This study presents and compares inorganic chlorine (Cly) derived from observations with the HALO research aircraft in the Antarctic late winter–early fall 2019 and the Arctic winter 2015–2016. Trend-corrected correlations from the Northern Hemisphere show excellent agreement with those from the Southern Hemisphere. After observation allocation inside and outside the vortex based on N2O measurements, results of the two campaigns reveal substantial differences in Cly within the respective vortex.
Meike K. Rotermund, Vera Bense, Martyn P. Chipperfield, Andreas Engel, Jens-Uwe Grooß, Peter Hoor, Tilman Hüneke, Timo Keber, Flora Kluge, Benjamin Schreiner, Tanja Schuck, Bärbel Vogel, Andreas Zahn, and Klaus Pfeilsticker
Atmos. Chem. Phys., 21, 15375–15407,Short summary
Airborne total bromine (Brtot) and tracer measurements suggest Brtot-rich air masses persistently protruded into the lower stratosphere (LS), creating a high Brtot region over the North Atlantic in fall 2017. The main source is via isentropic transport by the Asian monsoon and to a lesser extent transport across the extratropical tropopause as quantified by a Lagrange model. The transport of Brtot via Central American hurricanes is also observed. Lastly, the impact of Brtot on LS O3 is assessed.
Thorsten Kaluza, Daniel Kunkel, and Peter Hoor
Weather Clim. Dynam., 2, 631–651,Short summary
We present a 10-year analysis on the occurrence of strong wind shear in the Northern Hemisphere, focusing on the region around the transport barrier that separates the first two layers of the atmosphere. The major result of our analysis is that strong wind shear above a certain threshold occurs frequently and nearly exclusively in this region, which, as an indicator for turbulent mixing, might have major implications concerning the separation efficiency of the transport barrier.
Franziska Köllner, Johannes Schneider, Megan D. Willis, Hannes Schulz, Daniel Kunkel, Heiko Bozem, Peter Hoor, Thomas Klimach, Frank Helleis, Julia Burkart, W. Richard Leaitch, Amir A. Aliabadi, Jonathan P. D. Abbatt, Andreas B. Herber, and Stephan Borrmann
Atmos. Chem. Phys., 21, 6509–6539,Short summary
We present in situ observations of vertically resolved particle chemical composition in the summertime Arctic lower troposphere. Our analysis demonstrates the strong vertical contrast between particle properties within the boundary layer and aloft. Emissions from vegetation fires and anthropogenic sources in northern Canada, Europe, and East Asia influenced particle composition in the free troposphere. Organics detected in Arctic aerosol particles can partly be identified as dicarboxylic acids.
Johannes Schneider, Ralf Weigel, Thomas Klimach, Antonis Dragoneas, Oliver Appel, Andreas Hünig, Sergej Molleker, Franziska Köllner, Hans-Christian Clemen, Oliver Eppers, Peter Hoppe, Peter Hoor, Christoph Mahnke, Martina Krämer, Christian Rolf, Jens-Uwe Grooß, Andreas Zahn, Florian Obersteiner, Fabrizio Ravegnani, Alexey Ulanovsky, Hans Schlager, Monika Scheibe, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Martin Zöger, and Stephan Borrmann
Atmos. Chem. Phys., 21, 989–1013,Short summary
During five aircraft missions, we detected aerosol particles containing meteoric material in the lower stratosphere. The stratospheric measurements span a latitude range from 15 to 68° N, and we find that at potential temperature levels of more than 40 K above the tropopause; particles containing meteoric material occur at similar abundance fractions across latitudes and seasons. We conclude that meteoric material is efficiently distributed between high and low latitudes by isentropic mixing.
W. Richard Leaitch, John K. Kodros, Megan D. Willis, Sarah Hanna, Hannes Schulz, Elisabeth Andrews, Heiko Bozem, Julia Burkart, Peter Hoor, Felicia Kolonjari, John A. Ogren, Sangeeta Sharma, Meng Si, Knut von Salzen, Allan K. Bertram, Andreas Herber, Jonathan P. D. Abbatt, and Jeffrey R. Pierce
Atmos. Chem. Phys., 20, 10545–10563,Short summary
Black carbon is a factor in the warming of the Arctic atmosphere due to its ability to absorb light, but the uncertainty is high and few observations have been made in the high Arctic above 80° N. We combine airborne and ground-based observations in the springtime Arctic, at and above 80° N, with simulations from a global model to show that light absorption by black carbon may be much larger than modelled. However, the uncertainty remains high.
Marius Hauck, Harald Bönisch, Peter Hoor, Timo Keber, Felix Ploeger, Tanja J. Schuck, and Andreas Engel
Atmos. Chem. Phys., 20, 8763–8785,Short summary
This study features an extended inversion method that includes transport across the extratropical tropopause to derive age spectra in the lowermost stratosphere from in situ trace gas measurements. The refined method is validated in a model setup and applied to data gained with the HALO research aircraft. Results are congruent with the findings of previous studies so that the method provides a promising toolset for the analysis of stratospheric dynamics based on observations in the future.
Heiko Bozem, Peter Hoor, Daniel Kunkel, Franziska Köllner, Johannes Schneider, Andreas Herber, Hannes Schulz, W. Richard Leaitch, Amir A. Aliabadi, Megan D. Willis, Julia Burkart, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 19, 15049–15071,Short summary
We present airborne trace gas measurements in the European and Canadian Arctic for July 2014 and April 2015. Based on CO and CO2 in situ data as well as 10 d kinematic back trajectories, we characterize the prevailing transport regimes and derive a tracer-based diagnostic for the determination of the polar dome boundary. Using the tracer-derived boundary, an analysis of the recent transport history of air masses within the polar dome reveals significant differences between spring and summer.
Daniel Kunkel, Peter Hoor, Thorsten Kaluza, Jörn Ungermann, Björn Kluschat, Andreas Giez, Hans-Christoph Lachnitt, Martin Kaufmann, and Martin Riese
Atmos. Chem. Phys., 19, 12607–12630,Short summary
In this study we present a mixing process around the tropopause in extratropical baroclinic waves. We analyze airborne data from a flight during the WISE campaign in autumn 2017 over the North Atlantic. We use idealized experiments to study the mixing process. Although the process occurs on a small geographical scale, it might be of importance due to its relation to a frequent feature of the extratropical UTLS. The process is relevant for STE but is not fully included in climatologies.
Andreas Marsing, Tina Jurkat-Witschas, Jens-Uwe Grooß, Stefan Kaufmann, Romy Heller, Andreas Engel, Peter Hoor, Jens Krause, and Christiane Voigt
Atmos. Chem. Phys., 19, 10757–10772,Short summary
We study the partitioning of inorganic chlorine into active (ozone-depleting) and reservoir species in the lowermost stratosphere of the Arctic polar vortex, using novel in situ aircraft measurements in winter 2015/2016. We observe a change in recovery pathways of the reservoirs HCl and ClONO2 with increasing potential temperature. A comparison with the CLaMS model relates the observations to the vortex-wide evolution and confirms unresolved discrepancies in the mid-winter HCl distribution.
Thorsten Kaluza, Daniel Kunkel, and Peter Hoor
Atmos. Chem. Phys., 19, 6621–6636,Short summary
We present a comprehensive mean evolution of the tropopause inversion layer in mid-latitudes, an atmospheric feature that is located in the region that separates the well-mixed troposphere and the stably stratified stratosphere. We counter-intuitively find this region, which is expected to stabilise atmospheric flow, to exhibit favourable conditions for turbulent exchange between troposphere and stratosphere. This is an important result concerning the overall assessment of exchange processes.
Meng Si, Erin Evoy, Jingwei Yun, Yu Xi, Sarah J. Hanna, Alina Chivulescu, Kevin Rawlings, Daniel Veber, Andrew Platt, Daniel Kunkel, Peter Hoor, Sangeeta Sharma, W. Richard Leaitch, and Allan K. Bertram
Atmos. Chem. Phys., 19, 3007–3024,Short summary
We investigated the importance of mineral dust, sea spray aerosol, and anthropogenic aerosol to the ice-nucleating particle (INP) population in the Canadian Arctic during spring 2016. The results suggest that mineral dust transported from the Gobi Desert was a major source of the INP population studied, and that sea spray aerosol decreased the ice-nucleating ability of mineral dust. The results should be useful for testing and improving models used to predict INPs and climate in the Arctic.
Jonathan P. D. Abbatt, W. Richard Leaitch, Amir A. Aliabadi, Allan K. Bertram, Jean-Pierre Blanchet, Aude Boivin-Rioux, Heiko Bozem, Julia Burkart, Rachel Y. W. Chang, Joannie Charette, Jai P. Chaubey, Robert J. Christensen, Ana Cirisan, Douglas B. Collins, Betty Croft, Joelle Dionne, Greg J. Evans, Christopher G. Fletcher, Martí Galí, Roya Ghahreman, Eric Girard, Wanmin Gong, Michel Gosselin, Margaux Gourdal, Sarah J. Hanna, Hakase Hayashida, Andreas B. Herber, Sareh Hesaraki, Peter Hoor, Lin Huang, Rachel Hussherr, Victoria E. Irish, Setigui A. Keita, John K. Kodros, Franziska Köllner, Felicia Kolonjari, Daniel Kunkel, Luis A. Ladino, Kathy Law, Maurice Levasseur, Quentin Libois, John Liggio, Martine Lizotte, Katrina M. Macdonald, Rashed Mahmood, Randall V. Martin, Ryan H. Mason, Lisa A. Miller, Alexander Moravek, Eric Mortenson, Emma L. Mungall, Jennifer G. Murphy, Maryam Namazi, Ann-Lise Norman, Norman T. O'Neill, Jeffrey R. Pierce, Lynn M. Russell, Johannes Schneider, Hannes Schulz, Sangeeta Sharma, Meng Si, Ralf M. Staebler, Nadja S. Steiner, Jennie L. Thomas, Knut von Salzen, Jeremy J. B. Wentzell, Megan D. Willis, Gregory R. Wentworth, Jun-Wei Xu, and Jacqueline D. Yakobi-Hancock
Atmos. Chem. Phys., 19, 2527–2560,Short summary
The Arctic is experiencing considerable environmental change with climate warming, illustrated by the dramatic decrease in sea-ice extent. It is important to understand both the natural and perturbed Arctic systems to gain a better understanding of how they will change in the future. This paper summarizes new insights into the relationships between Arctic aerosol particles and climate, as learned over the past five or so years by a large Canadian research consortium, NETCARE.
Hannes Schulz, Marco Zanatta, Heiko Bozem, W. Richard Leaitch, Andreas B. Herber, Julia Burkart, Megan D. Willis, Daniel Kunkel, Peter M. Hoor, Jonathan P. D. Abbatt, and Rüdiger Gerdes
Atmos. Chem. Phys., 19, 2361–2384,Short summary
Aircraft vertical profiles of black carbon (BC) aerosol from the High Canadian Arctic have shown systematic variability in different levels of the cold, stably stratified polar dome. During spring and summer, efficiencies of BC supply by transport (often from gas flaring and wildfire-affected regions) were different in the lower dome than at higher levels, as apparent from changes in mean particle size and mixing ratios with CO. Summer BC concentrations were a factor of 10 lower than in spring.
Jens Krause, Peter Hoor, Andreas Engel, Felix Plöger, Jens-Uwe Grooß, Harald Bönisch, Timo Keber, Björn-Martin Sinnhuber, Wolfgang Woiwode, and Hermann Oelhaf
Atmos. Chem. Phys., 18, 6057–6073,Short summary
We present tracer measurements of CO and N2O measured during the POLSTRACC aircraft campaign in winter 2015–2016. We found enhanced CO values relative to N2O in the polar lower stratosphere in addition to the ageing of this region during winter. By using model simulations it was possible to link this enhancement to an increased mixing of the tropical tropopause. We thus conclude that the polar lower stratosphere in late winter is strongly influenced by quasi-isentropic mixing from the tropics.
Christian Rolf, Bärbel Vogel, Peter Hoor, Armin Afchine, Gebhard Günther, Martina Krämer, Rolf Müller, Stefan Müller, Nicole Spelten, and Martin Riese
Atmos. Chem. Phys., 18, 2973–2983,Short summary
The Asian monsoon is a pronounced circulation system linked to rapid vertical transport of surface air from India and east Asia in the summer months. We found, based on aircraft measurements, higher concentration of water vapor in the lowermost stratosphere caused by the Asian monsoon. Enrichment of water vapor concentrations in the lowermost stratosphere impacts the radiation budget and thus climate. Understanding those variations in water vapor is important for climate projections.
Franziska Köllner, Johannes Schneider, Megan D. Willis, Thomas Klimach, Frank Helleis, Heiko Bozem, Daniel Kunkel, Peter Hoor, Julia Burkart, W. Richard Leaitch, Amir A. Aliabadi, Jonathan P. D. Abbatt, Andreas B. Herber, and Stephan Borrmann
Atmos. Chem. Phys., 17, 13747–13766,Short summary
We conducted aircraft-based single particle chemical composition measurements in the Canadian high Arctic during summer. Our results provide evidence for a marine-biogenic influence on secondary formation of particulate trimethylamine in the Arctic boundary layer. Understanding emission sources and further processes controlling aerosol number concentration and chemical composition in the pristine Arctic summer is crucial for modeling future climate in the area.
Tilman Hüneke, Oliver-Alex Aderhold, Jannik Bounin, Marcel Dorf, Eric Gentry, Katja Grossmann, Jens-Uwe Grooß, Peter Hoor, Patrick Jöckel, Mareike Kenntner, Marvin Knapp, Matthias Knecht, Dominique Lörks, Sabrina Ludmann, Sigrun Matthes, Rasmus Raecke, Marcel Reichert, Jannis Weimar, Bodo Werner, Andreas Zahn, Helmut Ziereis, and Klaus Pfeilsticker
Atmos. Meas. Tech., 10, 4209–4234,Short summary
This paper describes a novel instrument for the aircraft-borne remote sensing of trace gases and liquid and solid water. Until recently, such measurements could only be evaluated under clear-sky conditions. We present a characterization and error assessment of the novel "scaling method", which allows for the retrieval of absolute trace gas concentrations under all sky conditions, significantly expanding the applicability of such measurements to study atmospheric photochemistry.
Marcus Klingebiel, André Ehrlich, Fanny Finger, Timo Röschenthaler, Suad Jakirlić, Matthias Voigt, Stefan Müller, Rolf Maser, Manfred Wendisch, Peter Hoor, Peter Spichtinger, and Stephan Borrmann
Atmos. Meas. Tech., 10, 3485–3498,Short summary
Microphysical and radiation measurements were collected with the unique AIRcraft TOwed Sensor Shuttle (AIRTOSS) – Learjet tandem platform. It is a combination of a Learjet 35A research aircraft and an instrumented aerodynamic bird, which can be detached from and retracted back to the aircraft during flight. AIRTOSS and Learjet are equipped with radiative, cloud microphysical, trace gas, and meteorological instruments to study cirrus clouds.
Andrea Mues, Maheswar Rupakheti, Christoph Münkel, Axel Lauer, Heiko Bozem, Peter Hoor, Tim Butler, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 8157–8176,Short summary
Ceilometer measurements taken in the Kathmandu Valley, Nepal, were used to study the temporal and spatial evolution of the mixing layer height in the valley. This provides important information on the vertical structure of the atmosphere and can thus also help to understand the mixing of air pollutants (e.g. black carbon) in the valley. The seasonal and diurnal cycles of the mixing layer were found to be highly dependent on meteorology and mainly anticorrelated to black carbon concentrations.
Klaus-D. Gottschaldt, Hans Schlager, Robert Baumann, Heiko Bozem, Veronika Eyring, Peter Hoor, Patrick Jöckel, Tina Jurkat, Christiane Voigt, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 17, 6091–6111,Short summary
We present upper-tropospheric trace gas measurements in the Asian summer monsoon anticyclone, obtained with the HALO research aircraft in September 2012. The anticyclone is one of the largest atmospheric features on Earth, but many aspects of it are not well understood. With the help of model simulations we find that entrainments from the tropopause region and the lower troposphere, combined with photochemistry and dynamical instabilities, can explain the observations.
Julia Burkart, Megan D. Willis, Heiko Bozem, Jennie L. Thomas, Kathy Law, Peter Hoor, Amir A. Aliabadi, Franziska Köllner, Johannes Schneider, Andreas Herber, Jonathan P. D. Abbatt, and W. Richard Leaitch
Atmos. Chem. Phys., 17, 5515–5535,Short summary
Our aircraft study for the first time systematically investigates aerosol size distributions, including ultrafine particles (5–20 nm in diameter), in the Arctic summertime atmosphere. We find that ultrafine particles occur very frequently in the boundary layer and not aloft, suggesting a surface source of these particles. Understanding aerosol properties and sources is crucial to predict climate and especially important in the Arctic as this region responds extremely fast to climate change.
Johannes Wagner, Andreas Dörnbrack, Markus Rapp, Sonja Gisinger, Benedikt Ehard, Martina Bramberger, Benjamin Witschas, Fernando Chouza, Stephan Rahm, Christian Mallaun, Gerd Baumgarten, and Peter Hoor
Atmos. Chem. Phys., 17, 4031–4052,
Bärbel Vogel, Gebhard Günther, Rolf Müller, Jens-Uwe Grooß, Armin Afchine, Heiko Bozem, Peter Hoor, Martina Krämer, Stefan Müller, Martin Riese, Christian Rolf, Nicole Spelten, Gabriele P. Stiller, Jörn Ungermann, and Andreas Zahn
Atmos. Chem. Phys., 16, 15301–15325,Short summary
The identification of transport pathways from the Asian monsoon anticyclone into the lower stratosphere is unclear. Global simulations with the CLaMS model demonstrate that source regions in Asia and in the Pacific Ocean have a significant impact on the chemical composition of the lower stratosphere of the Northern Hemisphere by flooding the extratropical lower stratosphere with young moist air masses. Two main horizontal transport pathways from the Asian monsoon anticyclone are identified.
W. Richard Leaitch, Alexei Korolev, Amir A. Aliabadi, Julia Burkart, Megan D. Willis, Jonathan P. D. Abbatt, Heiko Bozem, Peter Hoor, Franziska Köllner, Johannes Schneider, Andreas Herber, Christian Konrad, and Ralf Brauner
Atmos. Chem. Phys., 16, 11107–11124,Short summary
Thought to be mostly unimportant for summertime Arctic liquid-water clouds, airborne observations show that atmospheric aerosol particles 50 nm in diameter or smaller and most likely from natural sources are often involved in cloud formation in the pristine Arctic summer. The result expands the reference for aerosol forcing of climate. Further, for extremely low droplet concentrations, no evidence is found for a connection between cloud liquid water and aerosol particle concentrations.
Stefan Müller, Peter Hoor, Heiko Bozem, Ellen Gute, Bärbel Vogel, Andreas Zahn, Harald Bönisch, Timo Keber, Martina Krämer, Christian Rolf, Martin Riese, Hans Schlager, and Andreas Engel
Atmos. Chem. Phys., 16, 10573–10589,Short summary
In situ airborne measurements performed during TACTS/ESMVal 2012 were analysed to investigate the chemical compostion of the upper troposphere and lower stratosphere. N2O, CO and O3 data show an increase in tropospherically affected air masses within the extratropical stratosphere from August to September 2012, which originate from the Asian monsoon region. Thus, the Asian monsoon anticyclone significantly affected the chemical composition of the extratropical stratosphere during summer 2012.
Amir A. Aliabadi, Jennie L. Thomas, Andreas B. Herber, Ralf M. Staebler, W. Richard Leaitch, Hannes Schulz, Kathy S. Law, Louis Marelle, Julia Burkart, Megan D. Willis, Heiko Bozem, Peter M. Hoor, Franziska Köllner, Johannes Schneider, Maurice Levasseur, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 7899–7916,Short summary
For the first time, ship emissions of an ice-breaker, the Amundsen, is characterized while breaking ice in the Canadian Arctic using the plume intercepts by the Polar 6 aircraft. The study is novel, estimating lower plume expansion rates over the stable Arctic marine boundary layer and different emissions factors for oxides of nitrogen, black carbon, and carbon monoxide, compared to plume intercept studies in mid latitudes. These results can inform policy making and emission inventory datasets.
Megan D. Willis, Julia Burkart, Jennie L. Thomas, Franziska Köllner, Johannes Schneider, Heiko Bozem, Peter M. Hoor, Amir A. Aliabadi, Hannes Schulz, Andreas B. Herber, W. Richard Leaitch, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 7663–7679,Short summary
We present a case study focused on an aerosol growth event observed in the Canadian High Arctic during summer. Using measurements of aerosol chemical and physical properties we find evidence for aerosol growth into cloud condensation nuclei-active sizes, through marine-influenced secondary organic aerosol formation. Understanding the mechanisms that control the formation and growth of aerosol is crucial for our ability to predict cloud properties, and therefore radiative balance and climate.
Florian Berkes, Peter Hoor, Heiko Bozem, Daniel Kunkel, Michael Sprenger, and Stephan Henne
Atmos. Chem. Phys., 16, 6011–6025,Short summary
We presented airborne measurements of CO2 and O3 across the entrainment zone over a semi-remote environment in southwestern Germany in late summer 2011 . For the first time CO2 and O3 were used as tracer to identify mixing through this transport barrier. We demonstrated that the tracer--tracer correlation of CO2 and O3 is a powerful tool to identify entrainment and mixing.
N. Sobanski, M. J. Tang, J. Thieser, G. Schuster, D. Pöhler, H. Fischer, W. Song, C. Sauvage, J. Williams, J. Fachinger, F. Berkes, P. Hoor, U. Platt, J. Lelieveld, and J. N. Crowley
Atmos. Chem. Phys., 16, 4867–4883,Short summary
The nitrate radical (NO3) is an important nocturnal oxidant. By measuring NO3, its precursors (nitrogen dioxide and ozone) and several trace gases with which it reacts, we examined the chemical and meteorological factors influencing the lifetime of NO3 at a semi-rural mountain site. Unexpectedly long lifetimes, approaching 1 h, were observed on several nights and were associated with a low-lying residual layer. We discuss the role of other reactions that convert NO2 to NO3.
D. Kunkel, P. Hoor, and V. Wirth
Atmos. Chem. Phys., 16, 541–560,Short summary
By conducting various simulations of dry and moist baroclinic life cycles, we aimed to improve the understanding of whether dynamical or diabatic processes are more relevant to form a tropopause inversion layer at midlatitudes. Most importantly, our experiments highlighted the role of different moisture related processes for the formation and evolution of the tropopause inversion layer with varying relevance and strength in different phases of the baroclinic life cycles.
Christiane Hofmann, Astrid Kerkweg, Peter Hoor, and Patrick Jöckel
Atmos. Chem. Phys. Discuss.,
Revised manuscript not acceptedShort summary
Ozone enhancements at the surface, caused by descending stratospheric air masses along deep tropopause folds, can be reproduced using the model system MECO(n). It is shown that stratosphere-troposphere-exchange (STE) in the vicinity of a tropopause fold occurs in regions of turbulence and diabatic processes. The efﬁciency of mixing is quantiﬁed, showing that almost all of the air masses originating in the tropopause fold are transported into the troposphere during the following two days.
C. Rolf, A. Afchine, H. Bozem, B. Buchholz, V. Ebert, T. Guggenmoser, P. Hoor, P. Konopka, E. Kretschmer, S. Müller, H. Schlager, N. Spelten, O. Sumińska-Ebersoldt, J. Ungermann, A. Zahn, and M. Krämer
Atmos. Chem. Phys., 15, 9143–9158,
W. Frey, R. Schofield, P. Hoor, D. Kunkel, F. Ravegnani, A. Ulanovsky, S. Viciani, F. D'Amato, and T. P. Lane
Atmos. Chem. Phys., 15, 6467–6486,Short summary
This study examines the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system, using the WRF model. Passive tracers are initialised to study the impact of the deep convection on the tracers and water vapour. We use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.
R. Pommrich, R. Müller, J.-U. Grooß, P. Konopka, F. Ploeger, B. Vogel, M. Tao, C. M. Hoppe, G. Günther, N. Spelten, L. Hoffmann, H.-C. Pumphrey, S. Viciani, F. D'Amato, C. M. Volk, P. Hoor, H. Schlager, and M. Riese
Geosci. Model Dev., 7, 2895–2916,Short summary
A version of the chemical transport model CLaMS is presented, which features a simplified (numerically inexpensive) chemistry scheme. The model results using this version of CLaMS show a good representation of anomaly fields of CO, CH4, N2O, and CFC-11 in the lower stratosphere. CO measurements of three instruments (COLD, HAGAR, and Falcon-CO) in the lower tropical stratosphere (during the campaign TROCCINOX in 2005) have been compared and show a good agreement within the error bars.
B. Vogel, G. Günther, R. Müller, J.-U. Grooß, P. Hoor, M. Krämer, S. Müller, A. Zahn, and M. Riese
Atmos. Chem. Phys., 14, 12745–12762,Short summary
Enhanced tropospheric trace gases (e.g. pollutants) were measured in situ in the lowermost stratosphere over Northern Europe on 26 September 2012 during the TACTS aircraft campaign. We found that the combination of rapid uplift by a typhoon and eastward eddy shedding from the Asian monsoon anticyclone is a novel fast transport pathway that may carry boundary emissions from Southeast Asia/western Pacific within approximately 5 weeks to the lowermost stratosphere in Northern Europe.
M. Riese, H. Oelhaf, P. Preusse, J. Blank, M. Ern, F. Friedl-Vallon, H. Fischer, T. Guggenmoser, M. Höpfner, P. Hoor, M. Kaufmann, J. Orphal, F. Plöger, R. Spang, O. Suminska-Ebersoldt, J. Ungermann, B. Vogel, and W. Woiwode
Atmos. Meas. Tech., 7, 1915–1928,
C. Liu, S. Beirle, T. Butler, P. Hoor, C. Frankenberg, P. Jöckel, M. Penning de Vries, U. Platt, A. Pozzer, M. G. Lawrence, J. Lelieveld, H. Tost, and T. Wagner
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J. Yoon, A. Pozzer, P. Hoor, D. Y. Chang, S. Beirle, T. Wagner, S. Schloegl, J. Lelieveld, and H. M. Worden
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Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)The atmospheric oxidizing capacity in China – Part 1: Roles of different photochemical processesBenefits of net-zero policies for future ozone pollution in ChinaSimulating impacts on UK air quality from net-zero forest planting scenariosUnderstanding offshore high-ozone events during TRACER-AQ 2021 in Houston: insights from WRF–CAMx photochemical modelingOpinion: Establishing a science-into-policy process for tropospheric ozone assessmentAtmospheric composition and climate impacts of a future hydrogen economyAssessment of isoprene and near-surface ozone sensitivities to water stress over the Euro-Mediterranean regionNighttime ozone in the lower boundary layer: insights from 3-year tower-based measurements in South China and regional air quality modelingWhat controls ozone sensitivity in the upper tropical troposphere?Modelling the impacts of emission changes on O3 sensitivity, atmospheric oxidation capacity, and pollution transport over the Catalonia regionA regional modelling study of halogen chemistry within a volcanic plume of Mt Etna's Christmas 2018 eruptionWeekly-derived top-down VOC fluxes over Europe from TROPOMI HCHO data in 2018–2021Constraining the budget of atmospheric carbonyl sulfide using a 3-D chemical transport modelAtmospheric CO2 inversion reveals the Amazon as a minor carbon source caused by fire emissions, with forest uptake offsetting about half of these emissionsRapid O3 assimilations – Part 2: Tropospheric O3 changes accompanied by declining NOx emissions in the USA and Europe in 2005–2020High-resolution air quality simulations of ozone exceedance events during the Lake Michigan Ozone StudySimulations of winter ozone in the Upper Green River basin, Wyoming, using WRF-ChemThe suitability of atmospheric oxygen measurements to constrain Western European fossil-fuel CO2 emissions and their trendsMeasurement report: Assessment of Asian emissions of ethane and propane with a chemistry transport model based on observations from the island of HaterumaSensitivity of northeastern US surface ozone predictions to the representation of atmospheric chemistry in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMMv1.0)Current status of model predictions on volatile organic compounds and impacts on surface ozone predictions during summer in ChinaDaytime isoprene nitrates under changing NOx and O3Atmospheric data support a multi-decadal shift in the global methane budget towards natural tropical emissionsAir quality and related health impact in the UNECE region: source attribution and scenario analysisFuture tropospheric ozone budget and distribution over East Asia under a Net Zero scenarioEast Asian methane emissions inferred from high-resolution inversions of GOSAT and TROPOMI observations: a comparative and evaluative analysisTowards near-real-time air pollutant and greenhouse gas emissions: lessons learned from multiple estimates during the COVID-19 pandemicSpatiotemporal variation of radionuclide dispersion from nuclear power plant accidents using FLEXPART mini-ensemble modelingContinuous weekly monitoring of methane emissions from the Permian Basin by inversion of TROPOMI satellite observationsWestern European emission estimates of CFC-11, CFC-12 and CCl4 derived from atmospheric measurements from 2008 to 2021Evaluating modelled tropospheric columns of CH4, CO and O3 in the Arctic using ground-based FTIR measurementsUtility of Geostationary Lightning Mapper Derived Lightning NOx Emission Estimates in Air Quality Modeling StudiesInvestigating the differences in calculating global mean surface CO2 abundance: the impact of analysis methodologies and site selectionEstimating methane emissions in the Arctic nations using surface observations from 2008 to 2019Background nitrogen dioxide (NO2) over the United States and its implications for satellite observations and trends: effects of nitrate photolysis, aircraft, and open firesSeasonal, interannual and decadal variability of tropospheric ozone in the North Atlantic: comparison of UM-UKCA and remote sensing observations for 2005–2018Quantification of oil and gas methane emissions in the Delaware and Marcellus basins using a network of continuous tower-based measurementsInsights into Soil NO Emissions and the Contribution to Surface Ozone Formation in ChinaGlobal sensitivities of reactive N and S gas and particle concentrations and deposition to precursor emissions reductionsA high-resolution Global Aviation emissions Inventory based on ADS-B (GAIA) for 2019–2021Large simulated future changes in the nitrate radical under the CMIP6 SSP scenarios: implications for oxidation chemistryImpact of HO2 aerosol uptake on radical levels and O3 production during summertime in BeijingSource attribution of near-surface ozone trends in the United States during 1995–2019Exploring the drivers of tropospheric hydroxyl radical trends in the Geophysical Fluid Dynamics Laboratory AM4.1 atmospheric chemistry–climate modelComprehensive multiphase chlorine chemistry in the box model CAABA/MECCA: Implications to atmospheric oxidative capacityImpacts of land cover changes on biogenic emission and its contribution to ozone and secondary organic aerosol in ChinaHigh-resolution regional emission inventory contributes to the evaluation of policy effectiveness: a case study in Jiangsu Province, ChinaWhy is ozone in South Korea and the Seoul metropolitan area so high and increasing?Vehicular ammonia emissions: an underappreciated emission source in densely populated areasImproving ozone simulations in Asia via multisource data assimilation: results from an observing system simulation experiment with GEMS geostationary satellite observations
Jianing Dai, Guy P. Brasseur, Mihalis Vrekoussis, Maria Kanakidou, Kun Qu, Yijuan Zhang, Hongliang Zhang, and Tao Wang
Atmos. Chem. Phys., 23, 14127–14158,Short summary
In this study, we used a regional chemical transport model to characterize the different parameters of atmospheric oxidative capacity in recent chemical environments in China. These parameters include the production and destruction rates of ozone and other oxidants, the ozone production efficiency, the OH reactivity, and the length of the reaction chain responsible for the formation of ozone and ROx. They are also affected by the aerosol burden in the atmosphere.
Zhenze Liu, Oliver Wild, Ruth M. Doherty, Fiona M. O'Connor, and Steven T. Turnock
Atmos. Chem. Phys., 23, 13755–13768,Short summary
We investigate the impact of net-zero policies on surface ozone pollution in China. A chemistry–climate model is used to simulate ozone changes driven by local and external emissions, methane, and warmer climates. A deep learning model is applied to generate more robust ozone projection, and we find that the benefits of net-zero policies may be overestimated with the chemistry–climate model. Nevertheless, it is clear that the policies can still substantially reduce ozone pollution in future.
Gemma Purser, Mathew R. Heal, Edward J. Carnell, Stephen Bathgate, Julia Drewer, James I. L. Morison, and Massimo Vieno
Atmos. Chem. Phys., 23, 13713–13733,Short summary
Forest expansion is a ″net-zero“ pathway, but change in land cover alters air quality in many ways. This study combines tree planting suitability data with UK measured emissions of biogenic volatile organic compounds to simulate spatial and temporal changes in atmospheric composition for planting scenarios of four species. Decreases in fine particulate matter are relatively larger than increases in ozone, which may indicate a net benefit of tree planting on human health aspects of air quality.
Wei Li, Yuxuan Wang, Xueying Liu, Ehsan Soleimanian, Travis Griggs, James Flynn, and Paul Walter
Atmos. Chem. Phys., 23, 13685–13699,Short summary
This study examined high offshore ozone events in Galveston Bay and the Gulf of Mexico, using boat data and WRF–CAMx modeling during the TRACER-AQ 2021 field campaign. On average, high ozone is caused by chemistry due to the regional transport of volatile organic compounds and downwind advection of NOx from the ship channel. Two case studies show advection of ozone can be another process leading to high ozone, and accurate wind prediction is crucial for air quality forecasting in coastal areas.
Richard G. Derwent, David D. Parrish, and Ian C. Faloona
Atmos. Chem. Phys., 23, 13613–13623,Short summary
Elevated tropospheric ozone concentrations driven by anthropogenic precursor emissions are a world-wide health and environmental concern; however, this issue lacks a generally accepted understanding of the scientific issues. Here, we briefly outline the elements required to conduct an international assessment process to establish a conceptual model of the underpinning science and motivate international policy forums for regulating ozone production over hemispheric and global scales.
Nicola J. Warwick, Alex T. Archibald, Paul T. Griffiths, James Keeble, Fiona M. O'Connor, John A. Pyle, and Keith P. Shine
Atmos. Chem. Phys., 23, 13451–13467,Short summary
A chemistry–climate model has been used to explore the atmospheric response to changes in emissions of hydrogen and other species associated with a shift from fossil fuel to hydrogen use. Leakage of hydrogen results in indirect global warming, offsetting greenhouse gas emission reductions from reduced fossil fuel use. To maximise the benefit of hydrogen as an energy source, hydrogen leakage and emissions of methane, carbon monoxide and nitrogen oxides should be minimised.
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,Short summary
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.
Guowen He, Cheng He, Haofan Wang, Xiao Lu, Chenglei Pei, Xiaonuan Qiu, Chenxi Liu, Yiming Wang, Nanxi Liu, Jinpu Zhang, Lei Lei, Yiming Liu, Haichao Wang, Tao Deng, Qi Fan, and Shaojia Fan
Atmos. Chem. Phys., 23, 13107–13124,Short summary
We analyze nighttime ozone in the lower boundary layer (up to 500 m) from the 2017–2019 measurements at the Canton Tower and the WRF-CMAQ model. We identify a strong ability of the residual layer to store daytime ozone in the convective mixing layer, investigate the chemical and meteorological factors controlling nighttime ozone in the residual layer, and quantify the contribution of nighttime ozone in the residual layer to both the nighttime and the following day’s surface ozone air quality.
Clara M. Nussbaumer, Horst Fischer, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 23, 12651–12669,Short summary
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.
Alba Badia, Veronica Vidal, Sergi Ventura, Roger Curcoll, Ricard Segura, and Gara Villalba
Atmos. Chem. Phys., 23, 10751–10774,Short summary
Improving air quality is a top priority in urban areas. In this study, we used an air quality model to analyse the air quality changes occurring over the metropolitan area of Barcelona and other rural areas affected by transport of the atmospheric plume from the city during mobility restrictions. Our results show that mitigation strategies intended to reduce O3 should be designed according to the local meteorology, air transport, and particular ozone chemistry of the urban area.
Herizo Narivelo, Paul David Hamer, Virginie Marécal, Luke Surl, Tjarda Roberts, Sophie Pelletier, Béatrice Josse, Jonathan Guth, Mickaël Bacles, Simon Warnach, Thomas Wagner, Stefano Corradini, Giuseppe Salerno, and Lorenzo Guerrieri
Atmos. Chem. Phys., 23, 10533–10561,Short summary
Volcanic emissions emit large quantities of gases and primary aerosols that can play an important role in atmospheric chemistry. We present a study of the fate of volcanic bromine emissions from the eruption of Mount Etna around Christmas 2018. Using a numerical model and satellite observations, we analyse the impact of the volcanic plume and how it modifies the composition of the air over the whole Mediterranean basin, in particular on tropospheric ozone through the bromine-explosion cycle.
Glenn-Michael Oomen, Jean-François Müller, Trissevgeni Stavrakou, Isabelle De Smedt, Thomas Blumenstock, Rigel Kivi, Maria Makarova, Mathias Palm, Amelie Röhling, Yao Té, Corinne Vigouroux, Martina M. Friedrich, Udo Frieß, François Hendrick, Alexis Merlaud, Ankie Piters, Andreas Richter, Michel Van Roozendael, and Thomas Wagner
Natural emissions from vegetation have a profound impact on air quality for their role in the formation of harmful tropospheric ozone and organic aerosols, yet these emissions are highly uncertain. In this study, we quantify emissions of organic gases over Europe using high-quality satellite measurements of formaldehyde. These satellite observations suggest that emissions from vegetation are much higher than predicted by models, especially in southern Europe.
Michael P. Cartwright, Richard J. Pope, Jeremy J. Harrison, Martyn P. Chipperfield, Chris Wilson, Wuhu Feng, David P. Moore, and Parvadha Suntharalingam
Atmos. Chem. Phys., 23, 10035–10056,Short summary
A 3-D chemical transport model, TOMCAT, is used to simulate global atmospheric carbonyl sulfide (OCS) distribution. Modelled OCS compares well with satellite observations of OCS from limb-sounding satellite observations. Model simulations also compare adequately with surface and atmospheric observations and suitably capture the seasonality of OCS and background concentrations.
Luana S. Basso, Chris Wilson, Martyn P. Chipperfield, Graciela Tejada, Henrique L. G. Cassol, Egídio Arai, Mathew Williams, T. Luke Smallman, Wouter Peters, Stijn Naus, John B. Miller, and Manuel Gloor
Atmos. Chem. Phys., 23, 9685–9723,Short summary
The Amazon’s carbon balance may have changed due to forest degradation, deforestation and warmer climate. We used an atmospheric model and atmospheric CO2 observations to quantify Amazonian carbon emissions (2010–2018). The region was a small carbon source to the atmosphere, mostly due to fire emissions. Forest uptake compensated for ~ 50 % of the fire emissions, meaning that the remaining forest is still a small carbon sink. We found no clear evidence of weakening carbon uptake over the period.
Rui Zhu, Zhaojun Tang, Xiaokang Chen, Xiong Liu, and Zhe Jiang
Atmos. Chem. Phys., 23, 9745–9763,Short summary
Ozone Monitoring Instrument (OMI) and surface O3 observations are used to investigate the changes in tropospheric O3 in the USA and Europe in 2005–2020. The surface-based assimilations show limited changes in surface and tropospheric column O3. The OMI-based assimilations show larger decreases in tropospheric O3 columns in 2010–2014, related to a decline in free-tropospheric NO2. Analysis suggests limited impacts of local emissions decline on tropospheric O3 over the USA and Europe in 2005–2020.
R. Bradley Pierce, Monica Harkey, Allen Lenzen, Lee M. Cronce, Jason A. Otkin, Jonathan L. Case, David S. Henderson, Zac Adelman, Tsengel Nergui, and Christopher R. Hain
Atmos. Chem. Phys., 23, 9613–9635,Short summary
We evaluate two high-resolution model simulations with different meteorological inputs but identical chemistry and anthropogenic emissions, with the goal of identifying a model configuration best suited for characterizing air quality in locations where lake breezes commonly affect local air quality along the Lake Michigan shoreline. This analysis complements other studies in evaluating the impact of meteorological inputs and parameterizations on air quality in a complex environment.
Shreta Ghimire, Zachary J. Lebo, Shane Murphy, Stefan Rahimi, and Trang Tran
Atmos. Chem. Phys., 23, 9413–9438,Short summary
High wintertime ozone levels have occurred often in recent years in mountain basins with oil and gas production facilities. Photochemical modeling of ozone production serves as a basis for understanding the mechanism by which it occurs and for predictive capability. We present photochemical model simulations of ozone formation and accumulation in the Upper Green River basin, Wyoming, demonstrating the model's ability to simulate wintertime ozone and the sensitivity of ozone to its precursors.
Christian Rödenbeck, Karina E. Adcock, Markus Eritt, Maksym Gachkivsky, Christoph Gerbig, Samuel Hammer, Armin Jordan, Ralph F. Keeling, Ingeborg Levin, Fabian Maier, Andrew C. Manning, Heiko Moossen, Saqr Munassar, Penelope A. Pickers, Michael Rothe, Yasunori Tohjima, and Sönke Zaehle
The carbon dioxide content of the Earth atmosphere is increasing due to human emissions from burning of fossil fuels, causing global climate change. The strength of the fossil-fuel emissions is estimated by inventories based on energy data, but independent validation of these inventories has been recommended by the Intergovernmental Panel on Climate Change. Here we investigate the potential to validate inventories based on measurements of small changes in the atmospheric oxygen content.
Adedayo R. Adedeji, Stephen J. Andrews, Matthew J. Rowlinson, Mathew J. Evans, Alastair C. Lewis, Shigeru Hashimoto, Hitoshi Mukai, Hiroshi Tanimoto, Yasunori Tohjima, and Takuya Saito
Atmos. Chem. Phys., 23, 9229–9244,Short summary
We use the GEOS-Chem model to interpret observations of CO, C2H6, C3H8, NOx, NOy and O3 made from Hateruma Island in 2018. The model captures many synoptic-scale events and the seasonality of most pollutants at the site but underestimates C2H6 and C3H8 during the winter. These underestimates are unlikely to be reconciled by increases in biomass burning emissions but could be reconciled by increasing the Asian anthropogenic source of C2H6 and C3H8 by factors of around 2 and 3, respectively.
Bryan K. Place, William T. Hutzell, K. Wyat Appel, Sara Farrell, Lukas Valin, Benjamin N. Murphy, Karl M. Seltzer, Golam Sarwar, Christine Allen, Ivan R. Piletic, Emma L. D'Ambro, Emily Saunders, Heather Simon, Ana Torres-Vasquez, Jonathan Pleim, Rebecca H. Schwantes, Matthew M. Coggon, Lu Xu, William R. Stockwell, and Havala O. T. Pye
Atmos. Chem. Phys., 23, 9173–9190,Short summary
Ground-level ozone is a pollutant with adverse human health and ecosystem effects. Air quality models allow scientists to understand the chemical production of ozone and demonstrate impacts of air quality management plans. In this work, the role of multiple systems in ozone production was investigated for the northeastern US in summer. Model updates to chemical reaction rates and monoterpene chemistry were most influential in decreasing predicted ozone and improving agreement with observations.
Yongliang She, Jingyi Li, Xiaopu Lyu, Hai Guo, Momei Qin, Xiaodong Xie, Kangjia Gong, Fei Ye, Jianjiong Mao, Lin Huang, and Jianlin Hu
The evaluation of predicted VOC in current chemical transport model is limited in China due to the lack of routine measurements at multiple sites. In this study, we use multi-site VOC measurements to evaluate the CMAQ model predicted VOC and assess the impacts of VOC bias on O3 simulation. Our results demonstrate that current modelling setups and emission inventories are likely to underpredict VOC concentrations, and this underprediction of VOC contributes to lower O3 predictions in China.
Alfred W. Mayhew, Peter M. Edwards, and Jaqueline F. Hamilton
Atmos. Chem. Phys., 23, 8473–8485,Short summary
Isoprene nitrates are chemical species commonly found in the atmosphere that are important for their impacts on air quality and climate. This paper investigates modelled changes to daytime isoprene nitrate concentrations resulting from changes in NOx and O3. The results highlight the complex, nonlinear chemistry of this group of species under typical conditions for megacities such as Beijing, with many species showing increased concentrations when NOx is decreased and/or ozone is increased.
Alice Drinkwater, Paul I. Palmer, Liang Feng, Tim Arnold, Xin Lan, Sylvia E. Michel, Robert Parker, and Hartmut Boesch
Atmos. Chem. Phys., 23, 8429–8452,Short summary
Changes in atmospheric methane over the last few decades are largely unexplained. Previous studies have proposed different hypotheses to explain short-term changes in atmospheric methane. We interpret observed changes in atmospheric methane and stable isotope source signatures (2004–2020). We argue that changes over this period are part of a large-scale shift from high-northern-latitude thermogenic energy emissions to tropical biogenic emissions, particularly from North Africa and South America.
Claudio A. Belis and Rita Van Dingenen
Atmos. Chem. Phys., 23, 8225–8240,Short summary
The study assesses the influence that abating emissions in the rest of the world have on exposure and mortality due to ozone and fine particulate matter in the region covered by the Gothenburg protocol (UNECE, mainly Europe and North America). To that end, the impacts of pollutants derived from different geographic areas and anthropogenic sources are analysed in a series of scenarios including measures to abate air pollutants and greenhouse gas emissions with different levels of ambition.
Xuewei Hou, Oliver Wild, Bin Zhu, and James Lee
In response to the climate crisis, many countries have committed to net zero in a certain future year. The impacts of net zero scenario on tropospheric O3 are less well studied and remain unclear. In this study, we quantified the changes of tropospheric O3 budgets, spatiotemporal distributions of future surface O3 in East Asia and regional O3 source contributions for 2060 under a net zero scenario, using the NCAR Community Earth System Model (CESM) and online O3 tagging methods.
Ruosi Liang, Yuzhong Zhang, Wei Chen, Peixuan Zhang, Jingran Liu, Cuihong Chen, Huiqin Mao, Guofeng Shen, Zhen Qu, Zichong Chen, Minqiang Zhou, Pucai Wang, Robert J. Parker, Hartmut Boesch, Alba Lorente, Joannes D. Maasakkers, and Ilse Aben
Atmos. Chem. Phys., 23, 8039–8057,Short summary
We compare and evaluate East Asian methane emissions inferred from different satellite observations (GOSAT and TROPOMI). The results show discrepancies over northern India and eastern China. Independent ground-based observations are more consistent with TROPOMI-derived emissions in northern India and GOSAT-derived emissions in eastern China.
Marc Guevara, Hervé Petetin, Oriol Jorba, Hugo Denier van der Gon, Jeroen Kuenen, Ingrid Super, Claire Granier, Thierno Doumbia, Philippe Ciais, Zhu Liu, Robin D. Lamboll, Sabine Schindlbacher, Bradley Matthews, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 23, 8081–8101,Short summary
This study provides an intercomparison of European 2020 emission changes derived from official inventories, which are reported by countries under the framework of several international conventions and directives, and non-official near-real-time estimates, the use of which has significantly grown since the COVID-19 outbreak. The results of the work are used to produce recommendations on how best to approach and make use of near-real-time emissions for modelling and monitoring applications.
Seyed Omid Nabavi, Theodoros Christoudias, Yiannis Proestos, Christos Fountoukis, Huda Al-Sulaiti, and Jos Lelieveld
Atmos. Chem. Phys., 23, 7719–7739,Short summary
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.
Daniel J. Varon, Daniel J. Jacob, Benjamin Hmiel, Ritesh Gautam, David R. Lyon, Mark Omara, Melissa Sulprizio, Lu Shen, Drew Pendergrass, Hannah Nesser, Zhen Qu, Zachary R. Barkley, Natasha L. Miles, Scott J. Richardson, Kenneth J. Davis, Sudhanshu Pandey, Xiao Lu, Alba Lorente, Tobias Borsdorff, Joannes D. Maasakkers, and Ilse Aben
Atmos. Chem. Phys., 23, 7503–7520,Short summary
We use TROPOMI satellite observations to quantify weekly methane emissions from the US Permian oil and gas basin from May 2018 to October 2020. We find that Permian emissions are highly variable, with diverse economic and activity drivers. The most important drivers during our study period were new well development and natural gas price. Permian methane intensity averaged 4.6 % and decreased by 1 % per year.
Alison L. Redington, Alistair J. Manning, Stephan Henne, Francesco Graziosi, Luke M. Western, Jgor Arduini, Anita L. Ganesan, Christina M. Harth, Michela Maione, Jens Mühle, Simon O'Doherty, Joseph Pitt, Stefan Reimann, Matthew Rigby, Peter K. Salameh, Peter G. Simmonds, T. Gerard Spain, Kieran Stanley, Martin K. Vollmer, Ray F. Weiss, and Dickon Young
Atmos. Chem. Phys., 23, 7383–7398,Short summary
Chlorofluorocarbons (CFCs) were used in Europe pre-1990, damaging the stratospheric ozone layer. Legislation has controlled production and use, and global emissions have decreased sharply. The global rate of decline in CFC-11 recently slowed and was partly attributed to illegal emission in eastern China. This study concludes that emissions of CFC-11 in western Europe have not contributed to the unexplained part of the global increase in CFC-11 observed in the last decade.
Victoria A. Flood, Kimberly Strong, Cynthia H. Whaley, Kaley A. Walker, Thomas Blumenstock, James W. Hannigan, Johan Mellqvist, Justus Notholt, Mathias Palm, Amelie N. Röhling, Stephen Arnold, Stephen Beagley, Rong-You Chien, Jesper Christensen, Makoto Deushi, Srdjan Dobricic, Xinyi Dong, Joshua S. Fu, Michael Gauss, Wanmin Gong, Joakim Langner, Kathy S. Law, Louis Marelle, Tatsuo Onishi, Naga Oshima, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Manu A. Thomas, Svetlana Tsyro, and Steven Turnock
It is important to understand the composition of the Arctic atmosphere and how it is changing. Atmospheric models provide simulations that can inform policy. This study examines simulations of CH4, CO, and O3 by 11 models. Model performance is assessed by comparing results matched in space and time to measurements from five high-latitude ground-based infrared spectrometers. This work finds that models are generally underpredicting the concentrations of these gases in the Arctic troposphere.
Peiyang Cheng, Arastoo Pour-Biazar, Yuling Wu, Shi Kuang, Richard T. McNider, and William J. Koshak
Lightning-induced nitrogen monoxide (LNO) emission can be estimated from geostationary satellite observations. The present study uses the LNO emission estimates derived from geostationary satellite observations in an air quality modeling system to investigate the impact of LNO to air quality. Results indicate that significant ozone increase could be due to long-distance chemical transport, lightning activity in the upwind direction, and the mixing of high LNO (or ozone) plumes.
Zhendong Wu, Alex Vermeulen, Yousuke Sawa, Ute Karstens, Wouter Peters, Remco de Kok, Xin Lan, Yasuyuki Nagai, Akinori Ogi, and Oksana Tarasova
This study focuses on exploring the differences in calculating global surface CO2 and its growth rate, considering the impact of analysis methodologies and site selection. Our study reveals that the current global CO2 network has a good capacity to represent global surface CO2 and its growth rate and trends in atmospheric CO2 mass changes, although small differences exist in different analyses due to the impact of methodology and site selection.
Sophie Wittig, Antoine Berchet, Isabelle Pison, Marielle Saunois, Joël Thanwerdas, Adrien Martinez, Jean-Daniel Paris, Toshinobu Machida, Motoki Sasakawa, Douglas E. J. Worthy, Xin Lan, Rona L. Thompson, Espen Sollum, and Mikhail Arshinov
Atmos. Chem. Phys., 23, 6457–6485,Short summary
Here, an inverse modelling approach is applied to estimate CH4 sources and sinks in the Arctic from 2008 to 2019. We study the magnitude, seasonal patterns and trends from different sources during recent years. We also assess how the current observation network helps to constrain fluxes. We find that constraints are only significant for North America and, to a lesser extent, West Siberia, where the observation network is relatively dense. We find no clear trend over the period of inversion.
Ruijun Dang, Daniel J. Jacob, Viral Shah, Sebastian D. Eastham, Thibaud M. Fritz, Loretta J. Mickley, Tianjia Liu, Yi Wang, and Jun Wang
Atmos. Chem. Phys., 23, 6271–6284,Short summary
We use the GEOS-Chem model to better understand the magnitude and trend in free tropospheric NO2 over the contiguous US. Model underestimate of background NO2 is largely corrected by considering aerosol nitrate photolysis. Increase in aircraft emissions affects satellite retrievals by altering the NO2 shape factor, and this effect is expected to increase in future. We show the importance of properly accounting for the free tropospheric background in interpreting NO2 observations from space.
Maria Rosa Russo, Brian John Kerridge, Nathan Luke Abraham, James Keeble, Barry Graham Latter, Richard Siddans, James Weber, Paul Thomas Griffiths, John Adrian Pyle, and Alexander Thomas Archibald
Atmos. Chem. Phys., 23, 6169–6196,Short summary
Tropospheric ozone is an important component of the Earth system as it can affect both climate and air quality. In this work we use observed tropospheric ozone derived from satellite observations and compare it to tropospheric ozone from model simulations. Our aim is to investigate recent changes (2005–2018) in tropospheric ozone in the North Atlantic region and to understand what factors are driving such changes.
Zachary Barkley, Kenneth Davis, Natasha Miles, Scott Richardson, Aijun Deng, Benjamin Hmiel, David Lyon, and Thomas Lauvaux
Atmos. Chem. Phys., 23, 6127–6144,Short summary
Using methane monitoring instruments attached to towers, we measure methane concentrations and quantify methane emissions coming from the Marcellus and Permian oil and gas basins. In the Marcellus, emissions were 3 times higher than the state inventory across the entire monitoring period. In the Permian, we see a sharp decline in emissions aligning with the onset of the COVID-19 pandemic. Tower observational networks can be utilized in other basins for long-term monitoring of emissions.
Ling Huang, Jiong Fang, Jiaqiang Liao, Yarwood Greg, Hui Chen, Yangjun Wang, and Li Li
Surface ozone concentrations have emerged as a major environmental issue in China. Although control strategies aimed at reducing NOx emissions from conventional combustion sources are widely recognized, soil NOx emissions have received little attention. The impact of soil NO emissions on ground-level ozone concentration is yet to be evaluated. In this study, we estimated the soil NO emissions and evaluated its impact on ozone formation in China.
Yao Ge, Massimo Vieno, David S. Stevenson, Peter Wind, and Mathew R. Heal
Atmos. Chem. Phys., 23, 6083–6112,Short summary
The sensitivity of fine particles and reactive N and S species to reductions in precursor emissions is investigated using the EMEP MSC-W (European Monitoring and Evaluation Programme Meteorological Synthesizing Centre – West) atmospheric chemistry transport model. This study reveals that the individual emissions reduction has multiple and geographically varying co-benefits and small disbenefits on different species, demonstrating the importance of prioritizing regional emissions controls.
Roger Teoh, Zebediah Engberg, Marc Shapiro, Lynnette Dray, and Marc Stettler
Emissions from aircraft contribute to climate change and degrade air quality. We describe an up-to-date 4D emissions inventory of global aviation from 2019 to 2021 based on actual flown trajectories. In 2019, 40.2 million flights collectively travelled 61 billion kilometres using 283 Tg of fuel. Long-haul flights were responsible for 43 % of CO2. The emissions inventory is made available for use in future studies to evaluate the negative externalities arising from global aviation.
Scott Archer-Nicholls, Rachel Allen, Nathan L. Abraham, Paul T. Griffiths, and Alex T. Archibald
Atmos. Chem. Phys., 23, 5801–5813,Short summary
The nitrate radical is a major oxidant at nighttime, but much less is known about it than about the other oxidants ozone and OH. We use Earth system model calculations to show how the nitrate radical has changed in abundance from 1850–2014 and to 2100 under a range of different climate and emission scenarios. Depending on the emissions and climate scenario, significant increases are projected with implications for the oxidation of volatile organic compounds and the formation of fine aerosol.
Joanna E. Dyson, Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Stephen D. Worrall, Asan Bacak, Archit Mehra, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, C. Nicholas Hewitt, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, W. Joe F. Acton, William J. Bloss, Supattarachai Saksakulkrai, Jingsha Xu, Zongbo Shi, Roy M. Harrison, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lianfang Wei, Pingqing Fu, Xinming Wang, Stephen R. Arnold, and Dwayne E. Heard
Atmos. Chem. Phys., 23, 5679–5697,Short summary
The hydroxyl (OH) and closely coupled hydroperoxyl (HO2) radicals are vital for their role in the removal of atmospheric pollutants. In less polluted regions, atmospheric models over-predict HO2 concentrations. In this modelling study, the impact of heterogeneous uptake of HO2 onto aerosol surfaces on radical concentrations and the ozone production regime in Beijing in the summertime is investigated, and the implications for emissions policies across China are considered.
Pengwei Li, Yang Yang, Hailong Wang, Su Li, Ke Li, Pinya Wang, Baojie Li, and Hong Liao
Atmos. Chem. Phys., 23, 5403–5417,Short summary
We use a novel technique that can attribute O3 to precursors to investigate O3 changes in the United States during 1995–2019. We found that the US domestic energy and surface transportation emission reductions are primarily responsible for the O3 decrease in summer. In winter, factors such as nitrogen oxide emission reduction in the context of its inhibition of ozone production, increased aviation and shipping activities, and large-scale circulation changes contribute to the O3 increases.
Glen Chua, Vaishali Naik, and Larry Wayne Horowitz
Atmos. Chem. Phys., 23, 4955–4975,Short summary
The hydroxyl radical (OH) is an atmospheric
detergent, removing air pollutants and greenhouse gases like methane from the atmosphere. Thus, understanding how it is changing and responding to its various drivers is important for air quality and climate. We found that OH has increased by about 5 % globally from 1980 to 2014 in our model, mostly driven by increasing nitrogen oxide (NOx) emissions. This suggests potential climate tradeoffs from air quality policies solely targeting NOx emissions.
Meghna Soni, Rolf Sander, Lokesh K. Sahu, Domenico Taraborrelli, Pengfei Liu, Ankit Patel, Imran A. Girach, Andrea Pozzer, Sachin S. Gunthe, and Narendra Ojha
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 have been discussed. The updated chemical mechanism will be useful to interpret field measurements and for future air quality studies.
Jinlong Ma, Shengqiang Zhu, Siyu Wang, Peng Wang, Jianmin Chen, and Hongliang Zhang
Atmos. Chem. Phys., 23, 4311–4325,Short summary
An updated version of the CMAQ model with biogenic volatile organic compound (BVOC) emissions from MEGAN was applied to study the impacts of different land cover inputs on O3 and secondary organic aerosol (SOA) in China. The estimated BVOC emissions ranged from 25.42 to 37.39 Tg using different leaf area index (LAI) and land cover (LC) inputs. Those differences further induced differences of 4.8–6.9 ppb in O3 concentrations and differences of 5.3–8.4 µg m−3 in SOA concentrations in China.
Chen Gu, Lei Zhang, Zidie Xu, Sijia Xia, Yutong Wang, Li Li, Zeren Wang, Qiuyue Zhao, Hanying Wang, and Yu Zhao
Atmos. Chem. Phys., 23, 4247–4269,Short summary
We demonstrated the development of a high-resolution emission inventory and its application to evaluate the effectiveness of emission control actions, by incorporating the improved methodology, the best available data, and air quality modeling. We show that substantial efforts for emission controls indeed played an important role in air quality improvement even with worsened meteorological conditions and that the contributions of individual measures to emission reduction were greatly changing.
Nadia K. Colombi, Daniel J. Jacob, Laura Hyesung Yang, Shixian Zhai, Viral Shah, Stuart K. Grange, Robert M. Yantosca, Soontae Kim, and Hong Liao
Atmos. Chem. Phys., 23, 4031–4044,Short summary
Surface ozone, detrimental to human and ecosystem health, is very high and increasing in South Korea. Using a global model of the atmosphere, we found that emissions from South Korea and China contribute equally to the high ozone observed. We found that in the absence of all anthropogenic emissions over East Asia, ozone is still very high, implying that the air quality standard in South Korea is not practically achievable unless this background external to East Asia can be decreased.
Yifan Wen, Shaojun Zhang, Ye Wu, and Jiming Hao
Atmos. Chem. Phys., 23, 3819–3828,Short summary
This study established a high-resolution vehicular NH3 emission inventory for mainland China to quantify the absolute value and relative importance of on-road NH3 emissions for different regions, seasons and population densities. Our results indicate that the significant role of on-road NH3 emissions in populated urban areas may have been underappreciated, suggesting the control of vehicular NH3 emission can be a feasible and cost-effective way of mitigating haze pollution in urban areas.
Lei Shu, Lei Zhu, Juseon Bak, Peter Zoogman, Han Han, Song Liu, Xicheng Li, Shuai Sun, Juan Li, Yuyang Chen, Dongchuan Pu, Xiaoxing Zuo, Weitao Fu, Xin Yang, and Tzung-May Fu
Atmos. Chem. Phys., 23, 3731–3748,Short summary
We quantify the benefit of multisource observations (GEMS, LEO satellite, and surface) on ozone simulations in Asia. Data assimilation improves the monitoring of exceedance, spatial pattern, and diurnal variation of surface ozone, with the regional mean bias reduced from −2.1 to −0.2 ppbv. Data assimilation also better represents ozone vertical distributions in the middle to upper troposphere at low latitudes. Our results offer a valuable reference for future ozone simulations.
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Dickerson, R., Li, C., Li, Z., Marufu, L., Stehr, J., McClure, B., Krotkov, N., Chen, H., Wang, P., Xia, X., Ban, X., and Gong, F.: Aircraft Observations of Dust and Pollutants over NE China: Insight into the Meteorological Mechanisms of Long-Range Transport, J. Geophys. Res., 112, D24S90, https://doi.org/10.1029/2007JD008999, 2007. a
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Eckhardt, S., Stohl, A., Wernli, H., James, P., Forster, C., and Spichtinger, N.: A 15-Year Climatology of Warm Conveyor Belts, J. Climate, 17, 218–237, 2004. a
Han, H., Liu, J., Yuan, H., Jiang, F., Zhu, Y., Wu, Y., Wang, T., and Zhuang, B.: Impacts of Synoptic Weather Patterns and their Persistency on Free Tropospheric Carbon Monoxide Concentrations and Outflow in Eastern China, J. Geophys. Res.-Atmos., 123, 7024–7046, https://doi.org/10.1029/2017JD028172, 2018. a
Heald, C., Jacob, D., Fiore, A., Emmons, L., Gille, J., Deeter, M., Warner, J., Edwards, D., Crawford, J., Hamlin, A., Sachse, G., and Browell, E.: Asian outflow and trans-Pacific transport of carbon monoxide and ozone pollution: An integrated satellite, aircraft and model perspective, J. Geophys. Res., 108, 4804, https://doi.org/10.1029/2003JD003507, 2003. a, b, c
Lamarque, J.-F., Bond, T. C., Eyring, V., Granier, C., Heil, A., Klimont, Z., Lee, D., Liousse, C., Mieville, A., Owen, B., Schultz, M. G., Shindell, D., Smith, S. J., Stehfest, E., Van Aardenne, J., Cooper, O. R., Kainuma, M., Mahowald, N., McConnell, J. R., Naik, V., Riahi, K., and van Vuuren, D. P.: Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application, Atmos. Chem. Phys., 10, 7017–7039, https://doi.org/10.5194/acp-10-7017-2010, 2010. a
Lelieveld, J., Bourtsoukidis, E., Brühl, C., Fischer, H., Fuchs, H., Harder, H., Hofzumahaus, A., Holland, F., Marno, D., Neumaier, M., Pozzer, A., Schlager, H., Williams, J., Zahn, A., and Ziereis, H.: The South Asian monsoon–pollution pump and purifier, Science, 361, 270–273, https://doi.org/10.1126/science.aar2501, 2018. a, b
Liang, Q., Jaeglé, L., Hudman, R., Turquety, S., Jacob, D., Avery, M., Browell, E., Sachse, G., Blake, D., Brune, W., Ren, X., Cohen, R., Dibb, J., Fried, A., Fuelberg, H., Porter, M., Heikes, B., Huey, G., Singh, H., and Wennberg, P.: Summertime influence of Asian pollution in the free troposphere over North America, J. Geophys. Res.-Atmos., 112, D12S11, https://doi.org/10.1029/2006JD007919, 2007. a, b
Liu, J., Drummond, J., Jones, D., Cao, Z., Bremer, H., Kar, J., Zou, J., Florian, N., and Gille, J.: Large horizontal gradients in atmospheric CO at the synoptic scale as seen by spaceborne Measurements of Pollution in the Troposphere, J. Geophys. Res., 111, D02306, https://doi.org/10.1029/2005JD006076, 2006. a
Matsui, H., Kondo, Y., Moteki, N., Takegawa, N., Sahu, L. K., Zhao, Y., Fuelberg, H. E., Sessions, W. R., Diskin, G., Blake, D. R., Wisthaler, A., and Koike, M.: Seasonal variation of the transport of black carbon aerosol from the Asian continent to the Arctic during the ARCTAS aircraft campaign, J. Geophys. Res.-Atmos., 116, D05202, https://doi.org/10.1029/2010JD015067, 2011. a
Müller, S., Hoor, P., Bozem, H., Gute, E., Vogel, B., Zahn, A., Bönisch, H., Keber, T., Krämer, M., Rolf, C., Riese, M., Schlager, H., and Engel, A.: Impact of the Asian monsoon on the extratropical lower stratosphere: trace gas observations during TACTS over Europe 2012, Atmos. Chem. Phys., 16, 10573–10589, https://doi.org/10.5194/acp-16-10573-2016, 2016. a, b
Roiger, A., Schlager, H., Schäfler, A., Huntrieser, H., Scheibe, M., Aufmhoff, H., Cooper, O. R., Sodemann, H., Stohl, A., Burkhart, J., Lazzara, M., Schiller, C., Law, K. S., and Arnold, F.: In-situ observation of Asian pollution transported into the Arctic lowermost stratosphere, Atmos. Chem. Phys., 11, 10975–10994, https://doi.org/10.5194/acp-11-10975-2011, 2011. a
Santee, M. L., Manney, G. L., Livesey, N. J., Schwartz, M. J., Neu, J. L., and Read, W. G.: A comprehensive overview of the climatological composition of the Asian summer monsoon anticyclone based on 10 years of Aura Microwave Limb Sounder measurements, J. Geophys. Res.-Atmos., 122, 5491–5514, https://doi.org/10.1002/2016JD026408, 2017. a
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Turquety, S., Clerbaux, C., Law, K., Coheur, P.-F., Cozic, A., Szopa, S., Hauglustaine, D. A., Hadji-Lazaro, J., Gloudemans, A. M. S., Schrijver, H., Boone, C. D., Bernath, P. F., and Edwards, D. P.: CO emission and export from Asia: an analysis combining complementary satellite measurements (MOPITT, SCIAMACHY and ACE-FTS) with global modeling, Atmos. Chem. Phys., 8, 5187–5204, https://doi.org/10.5194/acp-8-5187-2008, 2008. a
Vogel, B., Günther, G., Müller, R., Grooß, J.-U., Hoor, P., Krämer, M., Müller, S., Zahn, A., and Riese, M.: Fast transport from Southeast Asia boundary layer sources to northern Europe: rapid uplift in typhoons and eastward eddy shedding of the Asian monsoon anticyclone, Atmos. Chem. Phys., 14, 12745–12762, https://doi.org/10.5194/acp-14-12745-2014, 2014. a
Vogel, B., Günther, G., Müller, R., Grooß, J.-U., Afchine, A., Bozem, H., Hoor, P., Krämer, M., Müller, S., Riese, M., Rolf, C., Spelten, N., Stiller, G. P., Ungermann, J., and Zahn, A.: Long-range transport pathways of tropospheric source gases originating in Asia into the northern lower stratosphere during the Asian monsoon season 2012, Atmos. Chem. Phys., 16, 15301–15325, https://doi.org/10.5194/acp-16-15301-2016, 2016. a
Yoon, J., Pozzer, A., Hoor, P., Chang, D. Y., Beirle, S., Wagner, T., Schloegl, S., Lelieveld, J., and Worden, H. M.: Technical Note: Temporal change in averaging kernels as a source of uncertainty in trend estimates of carbon monoxide retrieved from MOPITT, Atmos. Chem. Phys., 13, 11307–11316, https://doi.org/10.5194/acp-13-11307-2013, 2013. a
Yu, P., Rosenlof, K. H., Liu, S., Telg, H., Thornberry, T. D., Rollins, A. W., Portmann, R. W., Bai, Z., Ray, E. A., Duan, Y., Pan, L. L., Toon, O. B., Bian, J., and Gao, R.-S.: Efficient transport of tropospheric aerosol into the stratosphere via the Asian summer monsoon anticyclone, P. Natl. Acad. Sci. USA, 114, 6972–6977, https://doi.org/10.1073/pnas.1701170114, 2017. a
Zhang, L., Jacob, D. J., Boersma, K. F., Jaffe, D. A., Olson, J. R., Bowman, K. W., Worden, J. R., Thompson, A. M., Avery, M. A., Cohen, R. C., Dibb, J. E., Flock, F. M., Fuelberg, H. E., Huey, L. G., McMillan, W. W., Singh, H. B., and Weinheimer, A. J.: Transpacific transport of ozone pollution and the effect of recent Asian emission increases on air quality in North America: an integrated analysis using satellite, aircraft, ozonesonde, and surface observations, Atmos. Chem. Phys., 8, 6117–6136, https://doi.org/10.5194/acp-8-6117-2008, 2008. a, b, c
Our study presents a detailed analysis of the spatial and temporal distribution of elevated CO level in the upper troposphere over the Pacific using 20 years of MOPITT data. We create a climatology of severe pollution episodes and use trajectory calculations to link each particular pollution event detected in MOPITT satellite data with a distinct source region. Additionally, we analyse uplift mechanisms such as WCB-related upward transport.
Our study presents a detailed analysis of the spatial and temporal distribution of elevated CO...