Articles | Volume 14, issue 19
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Comparison of Fast In situ Stratospheric Hygrometer (FISH) measurements of water vapor in the upper troposphere and lower stratosphere (UTLS) with ECMWF (re)analysis data
Institute for Atmospheric and Climate Research, ETH Zurich, Zurich, Switzerland
Institut für Energie- und Klimaforschung: Stratosphäre (IEK-7), Forschungszentrum Jülich, Jülich, Germany
Institut für Energie- und Klimaforschung: Stratosphäre (IEK-7), Forschungszentrum Jülich, Jülich, Germany
Institut für Energie- und Klimaforschung: Stratosphäre (IEK-7), Forschungszentrum Jülich, Jülich, Germany
R. M. Forbes
European Centre for Medium-Range Weather Forecasts, Reading, UK
Institute for Atmospheric and Climate Research, ETH Zurich, Zurich, Switzerland
No articles found.
Leonie Villiger, Marina Dütsch, Sandrine Bony, Marie Lothon, Stephan Pfahl, Heini Wernli, Pierre-Etienne Brilouet, Patrick Chazette, Pierre Coutris, Julien Delanoë, Cyrille Flamant, Alfons Schwarzenboeck, Martin Werner, and Franziska Aemisegger
Atmos. Chem. Phys., 23, 14643–14672,Short summary
This study evaluates three numerical simulations performed with an isotope-enabled weather forecast model and investigates the coupling between shallow trade-wind cumulus clouds and atmospheric circulations on different scales. We show that the simulations reproduce key characteristics of shallow trade-wind clouds as observed during the field experiment EUREC4A and that the spatial distribution of stable-water-vapour isotopes is shaped by the overturning circulation associated with these clouds.
Jayanarayanan Kuttippurath, Gopalakrishna Pillai Gopikrishnan, Rolf Müller, Sophie Godin-Beekmann, and Jerome Brioude
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).Short summary
No measurements and no analyses show any sign of severe stratospheric ozone depletion in the tropics in contrast to a recent claim. It is very unlikely that an ozone hole would occur outside the Antarctic today with respect to the current stratospheric halogen levels.
Heini Wernli and Suzanne L. Gray
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).Short summary
This review provides a historic overview of research on how diabatic processes influence extratropical weather systems. We highlight that the combination of complementary research approaches – field experiments, diagnostics, numerical model experiments, potential vorticity theory, and consideration of climate change – was essential for reaching a new level of understanding where the interplay of dry dynamics with diabatic processes is considered as central to the field.
Francesco Cairo, Martina Krämer, Armin Afchine, Guido Di Donfrancesco, Luca Di Liberto, Sergey Khaykin, Lorenza Lucaferri, Valentin Mitev, Max Port, Christian Rolf, Marcel Snels, Nicole Spelten, Ralf Weigel, and Stephan Borrmann
Atmos. Meas. Tech., 16, 4899–4925,Short summary
Cirrus clouds have been observed over the Himalayan region between 10 km and the tropopause at 17–18 km. Data from backscattersonde, hygrometers, and particle cloud spectrometers have been compared to assess their consistency. Empirical relationships between optical parameters accessible with remote sensing lidars and cloud microphysical parameters (such as ice water content, particle number and surface area density, and particle aspherical fraction) have been established.
Elena De La Torre Castro, Tina Jurkat-Witschas, Armin Afchine, Volker Grewe, Valerian Hahn, Simon Kirschler, Martina Krämer, Johannes Lucke, Nicole Spelten, Heini Wernli, Martin Zöger, and Christiane Voigt
Atmos. Chem. Phys., 23, 13167–13189,Short summary
In this study, we show the differences in the microphysical properties between high-latitude (HL) cirrus and mid-latitude (ML) cirrus over the Arctic, North Atlantic, and central Europe during summer. The in situ measurements are combined with backward trajectories to investigate the influence of the region on cloud formation. We show that HL cirrus are characterized by a lower concentration of larger ice crystals when compared to ML cirrus.
Paul Konopka, Christian Rolf, Marc von Hobe, Sergey M. Khaykin, Benjamin Clouser, Elisabeth Moyer, Fabrizio Ravegnani, Francesco D'Amato, Silvia Viciani, Nicole Spelten, Armin Afchine, Martina Krämer, Fred Stroh, and Felix Ploeger
Atmos. Chem. Phys., 23, 12935–12947,Short summary
We studied water vapor in a critical region of the atmosphere, the Asian summer monsoon anticyclone, using rare in situ observations. Our study shows that extremely high water vapor values observed in the stratosphere within the Asian monsoon anticyclone still undergo significant freeze-drying and that water vapor concentrations set by the Lagrangian dry point are a better proxy for the stratospheric water vapor budget than rare observations of enhanced water mixing ratios.
Felix Ploeger, Thomas Birner, Edward Charlesworth, Paul Konopka, and Rolf Müller
We present a novel mechanism how regional anomalies in water vapour concentrations in the upper troposphere and lower stratosphere impact on regional atmospheric circulation systems. These impacts include a broadening upper-level Asian monsoon circulation and strengthened prevailing westerlies in the Pacific region. Current climate models have biases in simulating these regional water vapour anomalies and circulation impacts, but the biases can be avoided by improving the model transport.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
We show that the formation of Mediterranean cyclones follows the presence of cyclone over the North Atlantic. The distinct regions of cyclone activity in the Mediterranean in the different seasons can be linked to the atmospheric state, in particular the position of the polar jet over the North Atlantic. With this we now better understand the processes that lead to the formation of Mediterranean cyclones. We used a novel simulation framework in which we directly show and probe this connection.
Suvarna Fadnavis, Bernd Heinold, T. P. Sabin, Anne Kubin, Katty Huang, Alexandru Rap, and Rolf Müller
Atmos. Chem. Phys., 23, 10439–10449,Short summary
The influence of the COVID-19 lockdown on the Himalayas caused increases in snow cover and a decrease in runoff, ultimately leading to an enhanced snow water equivalent. Our findings highlight that, out of the two processes causing a retreat of Himalayan glaciers – (1) slow response to global climate change and (2) fast response to local air pollution – a policy action on the latter is more likely to be within the reach of possible policy action to help billions of people in southern Asia.
Lars Hoffmann, Paul Konopka, Jan Clemens, and Bärbel Vogel
Atmos. Chem. Phys., 23, 7589–7609,Short summary
Atmospheric convection plays a key role in tracer transport in the troposphere. Global meteorological forecasts and reanalyses typically have a coarse spatiotemporal resolution that does not adequately resolve the dynamics, transport, and mixing of air associated with storm systems or deep convection. We discuss the application of the extreme convection parameterization in a Lagrangian transport model to improve simulations of tracer transport from the boundary layer into the free troposphere.
Mark J. Rodwell and Heini Wernli
Weather Clim. Dynam., 4, 591–615,Short summary
Midlatitude storms and their downstream impacts have a major impact on society, yet their prediction is especially prone to uncertainty. While this can never be fully eliminated, we find that the initial rate of growth of uncertainty varies for a range of forecast models. Examination of the model of the European Centre for Medium-Range Weather Forecasts (ECMWF) suggests ways in which uncertainty growth could be reduced, leading to sharper and more reliable forecasts over the first few days.
Rolf Müller, Uli Pöschl, Thomas Koop, Thomas Peter, and Ken Carslaw
This paper is a short summary of the scientific work of Paul Crutzen and its impact on society. Particular focus is on his role as a founding member of the journal atmospheric chemistry and physics (ACP) and the Anthropocene.
Bärbel Vogel, Michael Volk, Johannes Wintel, Valentin Lauther, Jan Clemens, Jens-Uwe Grooß, Gebhard Günther, Lars Hoffmann, Johannes C. Laube, Rolf Müller, Felix Ploeger, and Fred Stroh
Atmospheric concentrations of the greenhouse gas carbon dioxide have increased substantially because of human activities. However, their sources in South Asia are poorly quantified. Here, we present high temporal and vertical resolution aircraft measurements up to 20 km during the Asian summer monsoon where rapid upward transport of surface pollutants to greater altitudes occurs. Using model simulations, we successfully reconstruct observed CO2 profiles and evaluate meteorological reanalysis.
Reinhold Spang, Rolf Müller, and Alexandru Rap
Cirrus clouds play an important role in the radiation budget of the Earth. Despite recent progress in the observations of cirrus, the radiative impact of thin cirrus clouds (UTC) in the tropopause region and in the lowermost stratosphere remains poorly constrained. Sensitivity model simulations with different ice parameter provide an uncertainty range for the radiative effect of UTCs. There is a need for better observed UTCs to enable the simulation of their potentially large effect on climate.
Katharina Heitmann, Michael Sprenger, Hanin Binder, Heini Wernli, and Hanna Joos
Warm conveyor belts (WCBs) are coherently ascending air streams that occur in extratropical cyclones where they form precipitation and often affect the large-scale flow. We quantified the key characteristics and impacts of WCBs and linked them to different phases in the cyclone life cycle and to different WCB branches. A climatology of these metrics revealed that WCBs are most intense during cyclone intensification and that the cyclonic and anticyclonic WCB branches show distinct differences.
Esther S. Breuninger, Julie Tolu, Iris Thurnherr, Franziska Aemisegger, Aryeh Feinberg, Sylvain Bouchet, Jeroen E. Sonke, Véronique Pont, Heini Wernli, and Lenny H. E. Winkel
Atmospheric deposition is an important source of selenium (Se) and other health-relevant trace elements to surface environments. We found that the variability in elemental concentrations in atmospheric deposition does not only reflect changes in emission sources but also weather conditions during atmospheric removal. Depending on the sources and if Se is derived more locally or from further away, the Se forms can be different affecting the bioavailability of Se atmospherically supplied to soils.
Gillian Young McCusker, Jutta Vüllers, Peggy Achtert, Paul Field, Jonathan J. Day, Richard Forbes, Ruth Price, Ewan O'Connor, Michael Tjernström, John Prytherch, Ryan Neely III, and Ian M. Brooks
Atmos. Chem. Phys., 23, 4819–4847,Short summary
In this study, we show that recent versions of two atmospheric models – the Unified Model and Integrated Forecasting System – overestimate Arctic cloud fraction within the lower troposphere by comparison with recent remote-sensing measurements made during the Arctic Ocean 2018 expedition. The overabundance of cloud is interlinked with the modelled thermodynamic structure, with strong negative temperature biases coincident with these overestimated cloud layers.
Julian Quinting, Christian Michael Grams, Edmund Kar-Man Chang, Stephan Pfahl, and Heini Wernli
Research in the last decades revealed that rapidly ascending airstreams in extratropical cyclones have an important effect on the evolution of downstream weather and predictability. In this study, we show that the occurrence of these airstreams over the North Pacific is modulated by tropical convection. Depending on the modulation, known atmospheric circulation patterns evolve quite differently which may affect extended-range predictions in the Atlantic-European region.
Jan Clemens, Bärbel Vogel, Lars Hoffmann, Sabine Griessbach, Nicole Thomas, Survana Fadnavis, Rolf Müller, Thomas Peter, and Felix Ploeger
The source regions of the Asian tropopause aerosol layer are under debate. We use balloon-borne measurements of the layer above Nainital (India) in August 2016 and atmospheric transport models, to find the ATALs source regions. Most air originate from the Tibetan plateau. However, the measured ATAL was stronger when more air originated from the Indo-Gangetic plain and weaker when more air originated from the Pacific. Hence, the results indicate important anthropogenic contributions to the ATAL.
Mauro Hermann, Matthias Röthlisberger, Arthur Gessler, Andreas Rigling, Cornelius Senf, Thomas Wohlgemuth, and Heini Wernli
Biogeosciences, 20, 1155–1180,Short summary
This study examines the multi-annual meteorological history of low-forest-greenness events in Europe's temperate and Mediterranean biome in 2002–2022. We systematically identify anomalies in temperature, precipitation, and weather systems as event precursors, with noteworthy differences between the two biomes. We also quantify the impact of the most extensive event in 2022 (37 % coverage), underlining the importance of understanding the forest–meteorology interaction in a changing climate.
Andrew Gettelman, Hugh Morrison, Trude Eidhammer, Katherine Thayer-Calder, Jian Sun, Richard Forbes, Zachary McGraw, Jiang Zhu, Trude Storelvmo, and John Dennis
Geosci. Model Dev., 16, 1735–1754,Short summary
Clouds are a critical part of weather and climate prediction. In this work, we document updates and corrections to the description of clouds used in several Earth system models. These updates include the ability to run the scheme on graphics processing units (GPUs), changes to the numerical description of precipitation, and a correction to the ice number. There are big improvements in the computational performance that can be achieved with GPU acceleration.
Yun Li, Christoph Mahnke, Susanne Rohs, Ulrich Bundke, Nicole Spelten, Georgios Dekoutsidis, Silke Groß, Christiane Voigt, Ulrich Schumann, Andreas Petzold, and Martina Krämer
Atmos. Chem. Phys., 23, 2251–2271,Short summary
The radiative effect of aviation-induced cirrus is closely related to ambient conditions and its microphysical properties. Our study investigated the occurrence of contrail and natural cirrus measured above central Europe in spring 2014. It finds that contrail cirrus appears frequently in the pressure range 200 to 245 hPa and occurs more often in slightly ice-subsaturated environments than expected. Avoiding slightly ice-subsaturated regions by aviation might help mitigate contrail cirrus.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 4, 157–173,Short summary
We investigate the dynamical origin of the lower-atmospheric potential vorticity (PV; linked to the intensity of cyclones) in Mediterranean cyclones. We quantify the contribution of the cyclone and the environment by tracing PV backward in time and space and linking it to the track of the cyclone. We find that the lower-tropospheric PV is produced shortly before the cyclone's stage of highest intensity. We investigate the driving processes and use a global dataset and a process-resolving one.
Hanna Joos, Michael Sprenger, Hanin Binder, Urs Beyerle, and Heini Wernli
Weather Clim. Dynam., 4, 133–155,Short summary
Warm conveyor belts (WCBs) are strongly ascending, cloud- and precipitation-forming airstreams in extratropical cyclones. In this study we assess their representation in a climate simulation and their changes under global warming. They become moister, become more intense, and reach higher altitudes in a future climate, implying that they potentially have an increased impact on the mid-latitude flow.
Andreas Schäfler, Michael Sprenger, Heini Wernli, Andreas Fix, and Martin Wirth
Atmos. Chem. Phys., 23, 999–1018,Short summary
In this study, airborne lidar profile measurements of H2O and O3 across a midlatitude jet stream are combined with analyses in tracer–trace space and backward trajectories. We highlight that transport and mixing processes in the history of the observed air masses are governed by interacting tropospheric weather systems on synoptic timescales. We show that these weather systems play a key role in the high variability of the paired H2O and O3 distributions near the tropopause.
Hanin Binder, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 4, 19–37,Short summary
Warm conveyor belts (WCBs) are the main cloud- and precipitation-producing airstreams in extratropical cyclones. The latent heat release that occurs during cloud formation often contributes to the intensification of the associated cyclone. Based on the Community Earth System Model Large Ensemble coupled climate simulations, we show that WCBs and associated latent heating will become stronger in a future climate and be even more important for explosive cyclone intensification than in the present.
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.
Clare E. Singer, Benjamin W. Clouser, Sergey M. Khaykin, Martina Krämer, Francesco Cairo, Thomas Peter, Alexey Lykov, Christian Rolf, Nicole Spelten, Armin Afchine, Simone Brunamonti, and Elisabeth J. Moyer
Atmos. Meas. Tech., 15, 4767–4783,Short summary
In situ measurements of water vapor in the upper troposphere are necessary to study cloud formation and hydration of the stratosphere but challenging due to cold–dry conditions. We compare measurements from three water vapor instruments from the StratoClim campaign in 2017. In clear sky (clouds), point-by-point differences were <1.5±8 % (<1±8 %). This excellent agreement allows detection of fine-scale structures required to understand the impact of convection on stratospheric water vapor.
Liubov Poshyvailo-Strube, Rolf Müller, Stephan Fueglistaler, Michaela I. Hegglin, Johannes C. Laube, C. Michael Volk, and Felix Ploeger
Atmos. Chem. Phys., 22, 9895–9914,Short summary
Brewer–Dobson circulation (BDC) controls the composition of the stratosphere, which in turn affects radiation and climate. As the BDC cannot be measured directly, it is necessary to infer its strength and trends indirectly. In this study, we test in the
model worlddifferent methods for estimating the mean age of air trends based on a combination of stratospheric water vapour and methane data. We also provide simple practical advice of a more reliable estimation of the mean age of air trends.
Andries Jan de Vries, Franziska Aemisegger, Stephan Pfahl, and Heini Wernli
Atmos. Chem. Phys., 22, 8863–8895,Short summary
The Earth's water cycle contains the common H2O molecule but also the less abundant, heavier HDO. We use their different physical properties to study tropical ice clouds in model simulations of the West African monsoon. Isotope signals reveal different processes through which ice clouds form and decay in deep-convective and widespread cirrus. Previously observed variations in upper-tropospheric vapour isotopes are explained by microphysical processes in convective updraughts and downdraughts.
Suvarna Fadnavis, Prashant Chavan, Akash Joshi, Sunil M. Sonbawne, Asutosh Acharya, Panuganti C. S. Devara, Alexandru Rap, Felix Ploeger, and Rolf Müller
Atmos. Chem. Phys., 22, 7179–7191,Short summary
We show that large amounts of anthropogenic aerosols are transported from South Asia to the northern Indian Ocean. These aerosols are then lifted into the UTLS by the ascending branch of the Hadley circulation. They are further transported to the Southern Hemisphere and downward via westerly ducts over the tropical Atlantic and Pacific. These aerosols increase tropospheric heating, resulting in an increase in water vapor, which is then transported to the UTLS.
Philipp Zschenderlein and Heini Wernli
Weather Clim. Dynam., 3, 391–411,Short summary
Precipitation and temperature are two of the most important variables describing our weather and climate. The relationship between these variables has been studied extensively; however, the role of specific weather systems in shaping this relationship has not been analysed yet. We therefore analyse whether intense precipitation occurs on warmer or on colder days and identify the relevant weather systems. In general, weather systems strongly influence this relationship, especially in winter.
Jan Clemens, Felix Ploeger, Paul Konopka, Raphael Portmann, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 22, 3841–3860,Short summary
Highly polluted air flows from the surface to higher levels of the atmosphere during the Asian summer monsoon. At high levels, the air is trapped within eddies. Here, we study how air masses can leave the eddy within its cutoff, how they distribute, and how their chemical composition changes. We found evidence for transport from the eddy to higher latitudes over the North Pacific and even Alaska. During transport, trace gas concentrations within cutoffs changed gradually, showing steady mixing.
Sergey M. Khaykin, Elizabeth Moyer, Martina Krämer, Benjamin Clouser, Silvia Bucci, Bernard Legras, Alexey Lykov, Armin Afchine, Francesco Cairo, Ivan Formanyuk, Valentin Mitev, Renaud Matthey, Christian Rolf, Clare E. Singer, Nicole Spelten, Vasiliy Volkov, Vladimir Yushkov, and Fred Stroh
Atmos. Chem. Phys., 22, 3169–3189,Short summary
The Asian monsoon anticyclone is the key contributor to the global annual maximum in lower stratospheric water vapour. We investigate the impact of deep convection on the lower stratospheric water using a unique set of observations aboard the high-altitude M55-Geophysica aircraft deployed in Nepal in summer 2017 within the EU StratoClim project. We find that convective plumes of wet air can persist within the Asian anticyclone for weeks, thereby enhancing the occurrence of high-level clouds.
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.
Katharina Hartmuth, Maxi Boettcher, Heini Wernli, and Lukas Papritz
Weather Clim. Dynam., 3, 89–111,Short summary
In this study, we introduce a novel method to objectively define and identify extreme Arctic seasons based on different surface variables. We find that such seasons are resulting from various combinations of unusual seasonal conditions. The occurrence or absence of different atmospheric processes strongly affects the character of extreme Arctic seasons. Further, changes in sea ice and sea surface temperature can strongly influence the formation of such a season in distinct regions.
Dina Khordakova, Christian Rolf, Jens-Uwe Grooß, Rolf Müller, Paul Konopka, Andreas Wieser, Martina Krämer, and Martin Riese
Atmos. Chem. Phys., 22, 1059–1079,Short summary
Extreme storms transport humidity from the troposphere to the stratosphere. Here it has a strong impact on the climate. With ongoing global warming, we expect more storms and, hence, an enhancement of this effect. A case study was performed in order to measure the impact of the direct injection of water vapor into the lower stratosphere. The measurements displayed a significant transport of water vapor into the lower stratosphere, and this was supported by satellite and reanalysis data.
Leonie Villiger, Heini Wernli, Maxi Boettcher, Martin Hagen, and Franziska Aemisegger
Weather Clim. Dynam., 3, 59–88,Short summary
The coupling between the large-scale atmospheric circulation and the clouds in the trade-wind region is complex and not yet fully understood. In this study, the formation pathway of two anomalous cloud layers over Barbados during the field campaign EUREC4A is described. The two case studies highlight the influence of remote weather systems on the local environmental conditions in Barbados.
Ian Boutle, Wayne Angevine, Jian-Wen Bao, Thierry Bergot, Ritthik Bhattacharya, Andreas Bott, Leo Ducongé, Richard Forbes, Tobias Goecke, Evelyn Grell, Adrian Hill, Adele L. Igel, Innocent Kudzotsa, Christine Lac, Bjorn Maronga, Sami Romakkaniemi, Juerg Schmidli, Johannes Schwenkel, Gert-Jan Steeneveld, and Benoît Vié
Atmos. Chem. Phys., 22, 319–333,Short summary
Fog forecasting is one of the biggest problems for numerical weather prediction. By comparing many models used for fog forecasting with others used for fog research, we hoped to help guide forecast improvements. We show some key processes that, if improved, will help improve fog forecasting, such as how water is deposited on the ground. We also showed that research models were not themselves a suitable baseline for comparison, and we discuss what future observations are required to improve them.
Philipp Zschenderlein and Heini Wernli
Nat. Hazards Earth Syst. Sci. Discuss.,
Preprint withdrawnShort summary
In early January 2021, Spain was affected by two extreme events – an unusually long cold spell and a heavy snowfall event associated with extratropical cyclone Filomena. In the study, we analyse the synoptic-dynamic development of the two extreme events. Cold air from the north was advected towards Spain and between 07 and 10 January, cyclone Filomena was responsible for major parts of the snowfall event. During this event, temperature and moisture contrasts accross Spain were very high.
Roman Attinger, Elisa Spreitzer, Maxi Boettcher, Heini Wernli, and Hanna Joos
Weather Clim. Dynam., 2, 1073–1091,Short summary
Diabatic processes affect the development of extratropical cyclones. This work provides a systematic assessment of the diabatic processes that modify potential vorticity (PV) in model simulations. PV is primarily produced by condensation and convection. Given favorable environmental conditions, long-wave radiative cooling and turbulence become the primary process at the cold and warm fronts, respectively. Turbulence and long-wave radiative heating produce negative PV anomalies at the fronts.
Fabienne Dahinden, Franziska Aemisegger, Heini Wernli, Matthias Schneider, Christopher J. Diekmann, Benjamin Ertl, Peter Knippertz, Martin Werner, and Stephan Pfahl
Atmos. Chem. Phys., 21, 16319–16347,Short summary
We use high-resolution numerical isotope modelling and Lagrangian backward trajectories to identify moisture transport pathways and governing physical and dynamical processes that affect the free-tropospheric humidity and isotopic variability over the eastern subtropical North Atlantic. Furthermore, we conduct a thorough isotope modelling validation with aircraft and remote-sensing observations of water vapour isotopes.
Prashant Chavan, Suvarna Fadnavis, Tanusri Chakroborty, Christopher E. Sioris, Sabine Griessbach, and Rolf Müller
Atmos. Chem. Phys., 21, 14371–14384,Short summary
Biomass burning (BB) over Asia is a strong source of carbonaceous aerosols during spring. Here, we show an outflow of Asian BB carbonaceous aerosols into the UTLS. These aerosols enhance atmospheric heating and produce circulation changes that lead to the enhancement of water vapor in the UTLS over the tropics. In the stratosphere, water vapor is further transported to the South Pole by the Brewer–Dobson circulation. Enhancement of water vapor in the UTLS has implications for climate change.
Jayanarayanan Kuttippurath, Wuhu Feng, Rolf Müller, Pankaj Kumar, Sarath Raj, Gopalakrishna Pillai Gopikrishnan, and Raina Roy
Atmos. Chem. Phys., 21, 14019–14037,Short summary
The Arctic winter/spring 2020 was one of the coldest with a strong and long-lasting vortex, high chlorine activation, severe denitrification, and unprecedented ozone loss. The loss was even equal to the levels of some of the warm Antarctic winters. Total column ozone values below 220 DU for several weeks and ozone loss saturation were observed during the period. These results show an unusual meteorology and warrant dedicated studies on the impact of climate change on ozone loss.
Ralf Weigel, Christoph Mahnke, Manuel Baumgartner, Martina Krämer, Peter Spichtinger, Nicole Spelten, Armin Afchine, Christian Rolf, Silvia Viciani, Francesco D'Amato, Holger Tost, and Stephan Borrmann
Atmos. Chem. Phys., 21, 13455–13481,Short summary
In July and August 2017, the StratoClim mission took place in Nepal with eight flights of the M-55 Geophysica at up to 20 km in the Asian monsoon anticyclone. New particle formation (NPF) next to cloud ice was detected in situ by abundant nucleation-mode aerosols (> 6 nm) along with ice particles (> 3 µm). NPF was observed mainly below the tropopause, down to 15 % being non-volatile residues. Observed intra-cloud NPF indicates its importance for the composition in the tropical tropopause layer.
Lukas Krasauskas, Jörn Ungermann, Peter Preusse, Felix Friedl-Vallon, Andreas Zahn, Helmut Ziereis, Christian Rolf, Felix Plöger, Paul Konopka, Bärbel Vogel, and Martin Riese
Atmos. Chem. Phys., 21, 10249–10272,Short summary
A Rossby wave (RW) breaking event was observed over the North Atlantic during the WISE measurement campaign in October 2017. Infrared limb sounding measurements of trace gases in the lower stratosphere, including high-resolution 3-D tomographic reconstruction, revealed complex spatial structures in stratospheric tracers near the polar jet related to previous RW breaking events. Backward-trajectory analysis and tracer correlations were used to study mixing and stratosphere–troposphere exchange.
Raphael Portmann, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 507–534,Short summary
We explore the three-dimensional life cycle of cyclonic structures (so-called PV cutoffs) near the tropopause. PV cutoffs are frequent weather systems in the extratropics that lead to high-impact weather. However, many unknowns exist regarding their evolution. We present a new method to track PV cutoffs as 3D objects in reanalysis data by following air parcels along the flow. We study the climatological life cycles of PV cutoffs in detail and propose a classification into three types.
Felix Ploeger, Mohamadou Diallo, Edward Charlesworth, Paul Konopka, Bernard Legras, Johannes C. Laube, Jens-Uwe Grooß, Gebhard Günther, Andreas Engel, and Martin Riese
Atmos. Chem. Phys., 21, 8393–8412,Short summary
We investigate the global stratospheric circulation (Brewer–Dobson circulation) in the new ECMWF ERA5 reanalysis based on age of air simulations, and we compare it to results from the preceding ERA-Interim reanalysis. Our results show a slower stratospheric circulation and higher age for ERA5. The age of air trend in ERA5 over the 1989–2018 period is negative throughout the stratosphere, related to multi-annual variability and a potential contribution from changes in the reanalysis system.
Xiaolu Yan, Paul Konopka, Marius Hauck, Aurélien Podglajen, and Felix Ploeger
Atmos. Chem. Phys., 21, 6627–6645,Short summary
Inter-hemispheric transport is important for understanding atmospheric tracers because of the asymmetry in emissions between the Southern Hemisphere (SH) and Northern Hemisphere (NH). This study finds that the air masses from the NH extratropics to the atmosphere are about 5 times larger than those from the SH extratropics. The interplay between the Asian summer monsoon and westerly ducts triggers the cross-Equator transport from the NH to the SH in boreal summer and fall.
Iris Thurnherr, Katharina Hartmuth, Lukas Jansing, Josué Gehring, Maxi Boettcher, Irina Gorodetskaya, Martin Werner, Heini Wernli, and Franziska Aemisegger
Weather Clim. Dynam., 2, 331–357,Short summary
Extratropical cyclones are important for the transport of moisture from low to high latitudes. In this study, we investigate how the isotopic composition of water vapour is affected by horizontal temperature advection associated with extratropical cyclones using measurements and modelling. It is shown that air–sea moisture fluxes induced by this horizontal temperature advection lead to the strong variability observed in the isotopic composition of water vapour in the marine boundary layer.
Maxi Boettcher, Andreas Schäfler, Michael Sprenger, Harald Sodemann, Stefan Kaufmann, Christiane Voigt, Hans Schlager, Donato Summa, Paolo Di Girolamo, Daniele Nerini, Urs Germann, and Heini Wernli
Atmos. Chem. Phys., 21, 5477–5498,Short summary
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation. We present a case study that involves aircraft, lidar and radar observations of water and clouds in a WCB ascending from western Europe across the Alps towards the Baltic Sea during the field campaigns HyMeX and T-NAWDEX-Falcon in October 2012. A probabilistic trajectory measure and an airborne tracer experiment were used to confirm the long pathway of the WCB.
Franziska Aemisegger, Raphaela Vogel, Pascal Graf, Fabienne Dahinden, Leonie Villiger, Friedhelm Jansen, Sandrine Bony, Bjorn Stevens, and Heini Wernli
Weather Clim. Dynam., 2, 281–309,Short summary
The interaction of clouds in the trade wind region with the atmospheric flow is complex and at the heart of uncertainties associated with climate projections. In this study, a natural tracer of atmospheric circulation is used to establish a link between air originating from dry regions of the midlatitudes and the occurrence of specific cloud patterns. Two pathways involving transport within midlatitude weather systems are identified, by which air is brought into the trades within 5–10 d.
Sabine Robrecht, Bärbel Vogel, Simone Tilmes, and Rolf Müller
Atmos. Chem. Phys., 21, 2427–2455,Short summary
Column ozone protects life on Earth from radiation damage. Stratospheric chlorine compounds cause immense ozone loss in polar winter. Whether similar loss processes can occur in the lower stratosphere above North America today or in future is a matter of debate. We show that these ozone loss processes are very unlikely today or in future independently of whether sulfate geoengineering is applied and that less than 0.1 % of column ozone would be destroyed by this process in any future scenario.
Annika Oertel, Michael Sprenger, Hanna Joos, Maxi Boettcher, Heike Konow, Martin Hagen, and Heini Wernli
Weather Clim. Dynam., 2, 89–110,Short summary
Convection embedded in the stratiform cloud band of strongly ascending airstreams in extratropical cyclones (so-called warm conveyor belts) can influence not only surface precipitation but also the upper-tropospheric potential vorticity (PV) and waveguide. The comparison of intense vs. moderate embedded convection shows that its strength alone is not a reliable measure for upper-tropospheric PV modification. Instead, characteristics of the ambient flow co-determine its dynamical significance.
Emmanouil Flaounas, Matthias Röthlisberger, Maxi Boettcher, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 71–88,Short summary
In this study we identify the wettest seasons globally and address their meteorological characteristics. We show that in different regions the wettest seasons occur in different times of the year and result from either unusually high frequencies of wet days and/or daily extremes. These high frequencies can be largely attributed to four specific weather systems, especially cyclones. Our analysis uses a thoroughly explained, novel methodology that could also be applied to climate models.
Marc von Hobe, Felix Ploeger, Paul Konopka, Corinna Kloss, Alexey Ulanowski, Vladimir Yushkov, Fabrizio Ravegnani, C. Michael Volk, Laura L. Pan, Shawn B. Honomichl, Simone Tilmes, Douglas E. Kinnison, Rolando R. Garcia, and Jonathon S. Wright
Atmos. Chem. Phys., 21, 1267–1285,Short summary
The Asian summer monsoon (ASM) is known to foster transport of polluted tropospheric air into the stratosphere. To test and amend our picture of ASM vertical transport, we analyse distributions of airborne trace gas observations up to 20 km altitude near the main ASM vertical conduit south of the Himalayas. We also show that a new high-resolution version of the global chemistry climate model WACCM is able to reproduce the observations well.
Sebastian Schemm, Heini Wernli, and Hanin Binder
Weather Clim. Dynam., 2, 55–69,Short summary
North Pacific cyclone intensities are reduced in winter, which is in contrast to North Atlantic cyclones and unexpected from the high available growth potential in winter. We investigate this intensity suppression from a cyclone life-cycle perspective and show that in winter Kuroshio cyclones propagate away from the region where they can grow more quickly, East China Sea cyclones are not relevant before spring, and Kamchatka cyclones grow in a region of reduced growth potential.
Sreeharsha Hanumanthu, Bärbel Vogel, Rolf Müller, Simone Brunamonti, Suvarna Fadnavis, Dan Li, Peter Ölsner, Manish Naja, Bhupendra Bahadur Singh, Kunchala Ravi Kumar, Sunil Sonbawne, Hannu Jauhiainen, Holger Vömel, Beiping Luo, Teresa Jorge, Frank G. Wienhold, Ruud Dirkson, and Thomas Peter
Atmos. Chem. Phys., 20, 14273–14302,Short summary
During boreal summer, anthropogenic sources yield the Asian Tropopause Aerosol Layer (ATAL), found in Asia between about 13 and 18 km altitude. Balloon-borne measurements of the ATAL conducted in northern India in 2016 show the strong variability of the ATAL. To explain its observed variability, model simulations are performed to deduce the origin of air masses on the Earth's surface, which is important to develop recommendations for regulations of anthropogenic surface emissions of the ATAL.
Joram J. D. Hooghiem, Maria Elena Popa, Thomas Röckmann, Jens-Uwe Grooß, Ines Tritscher, Rolf Müller, Rigel Kivi, and Huilin Chen
Atmos. Chem. Phys., 20, 13985–14003,Short summary
Wildfires release a large quantity of pollutants that can reach the stratosphere through pyro-convection events. In September 2017, a stratospheric plume was accidentally sampled during balloon soundings in northern Finland. The source of the plume was identified to be wildfire smoke based on in situ measurements of carbon monoxide (CO) and stable isotope analysis of CO. Furthermore, the age of the plume was estimated using backwards transport modelling to be ~24 d, with its origin in Canada.
Yuli Zhang, Mengchu Tao, Jinqiang Zhang, Yi Liu, Hongbin Chen, Zhaonan Cai, and Paul Konopka
Atmos. Chem. Phys., 20, 13343–13354,
Martina Krämer, Christian Rolf, Nicole Spelten, Armin Afchine, David Fahey, Eric Jensen, Sergey Khaykin, Thomas Kuhn, Paul Lawson, Alexey Lykov, Laura L. Pan, Martin Riese, Andrew Rollins, Fred Stroh, Troy Thornberry, Veronika Wolf, Sarah Woods, Peter Spichtinger, Johannes Quaas, and Odran Sourdeval
Atmos. Chem. Phys., 20, 12569–12608,Short summary
To improve the representations of cirrus clouds in climate predictions, extended knowledge of their properties and geographical distribution is required. This study presents extensive airborne in situ and satellite remote sensing climatologies of cirrus and humidity, which serve as a guide to cirrus clouds. Further, exemplary radiative characteristics of cirrus types and also in situ observations of tropical tropopause layer cirrus and humidity in the Asian monsoon anticyclone are shown.
Stefan Rüdisühli, Michael Sprenger, David Leutwyler, Christoph Schär, and Heini Wernli
Weather Clim. Dynam., 1, 675–699,Short summary
Most precipitation over Europe is linked to low-pressure systems, cold fronts, warm fronts, or high-pressure systems. Based on a massive computer simulation able to resolve thunderstorms, we quantify in detail how much precipitation these weather systems produced during 2000–2008. We find distinct seasonal and regional differences, such as fronts precipitating a lot in fall and winter over the North Atlantic but high-pressure systems mostly in summer over the continent by way of thunderstorms.
Raphael Portmann, Juan Jesús González-Alemán, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 597–615,Short summary
In September 2018 an intense Mediterranean cyclone with structural similarities to a hurricane, a so-called medicane, caused severe damage in Greece. Its development was uncertain, even just a few days in advance. The reason for this was uncertainties in the jet stream over the North Atlantic 3 d prior to cyclogenesis that propagated into the Mediterranean. They led to an uncertain position of the upper-level disturbance and, as a result, of the position and thermal structure of the cyclone.
Hanin Binder, Maxi Boettcher, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 577–595,Short summary
Warm conveyor belts (WCBs) are important cloud- and precipitation-producing airstreams in extratropical cyclones. By combining satellite observations with model data from a new reanalysis dataset, this study provides detailed observational insight into the vertical cloud structure of WCBs. We find that the reanalyses essentially capture the observed cloud pattern, but the observations reveal mesoscale structures not resolved by the temporally and spatially much coarser-resolution model data.
Mauro Hermann, Lukas Papritz, and Heini Wernli
Weather Clim. Dynam., 1, 497–518,Short summary
We find, by tracing backward in time, that air masses causing extensive melt of the Greenland Ice Sheet originate from further south and lower altitudes than usual. Their exceptional warmth further arises due to ascent and cloud formation, which is special compared to near-surface heat waves in the midlatitudes or the central Arctic. The atmospheric systems and transport pathways identified here are crucial in understanding and simulating the atmospheric control of the ice sheet in the future.
Daniel Steinfeld, Maxi Boettcher, Richard Forbes, and Stephan Pfahl
Weather Clim. Dynam., 1, 405–426,Short summary
The effect of latent heating on atmospheric blocking is investigated using numerical sensitivity experiments. The modification of latent heating in the upstream cyclone has substantial effects on the upper-tropospheric circulation, demonstrating that some blocking systems do not develop at all without upstream latent heating. The results highlight the importance of moist-diabatic processes for the dynamics of prolonged anticyclonic circulation anomalies.
Jonathon S. Wright, Xiaoyi Sun, Paul Konopka, Kirstin Krüger, Bernard Legras, Andrea M. Molod, Susann Tegtmeier, Guang J. Zhang, and Xi Zhao
Atmos. Chem. Phys., 20, 8989–9030,Short summary
High clouds are influential in tropical climate. Although reanalysis cloud fields are essentially model products, they are indirectly constrained by observations and offer global coverage with direct links to advanced water and energy cycle metrics, giving them many useful applications. We describe how high cloud fields are generated in reanalyses, assess their realism and reliability in the tropics, and evaluate how differences in these fields affect other aspects of the reanalysis state.
Andreas Petzold, Patrick Neis, Mihal Rütimann, Susanne Rohs, Florian Berkes, Herman G. J. Smit, Martina Krämer, Nicole Spelten, Peter Spichtinger, Philippe Nédélec, and Andreas Wahner
Atmos. Chem. Phys., 20, 8157–8179,Short summary
The first analysis of 15 years of global-scale water vapour and relative humidity observations by passenger aircraft in the MOZAIC and IAGOS programmes resolves detailed features of water vapour and ice-supersaturated air in the mid-latitude tropopause. Key results provide in-depth insight into seasonal and regional variability and chemical signatures of ice-supersaturated air masses, including trend analyses, and show a close link to cirrus clouds and their highly important effects on climate.
Iris Thurnherr, Anna Kozachek, Pascal Graf, Yongbiao Weng, Dimitri Bolshiyanov, Sebastian Landwehr, Stephan Pfahl, Julia Schmale, Harald Sodemann, Hans Christian Steen-Larsen, Alessandro Toffoli, Heini Wernli, and Franziska Aemisegger
Atmos. Chem. Phys., 20, 5811–5835,Short summary
Stable water isotopes (SWIs) are tracers of moist atmospheric processes. We analyse the impact of large- to small-scale atmospheric processes and various environmental conditions on the variability of SWIs using ship-based SWI measurement in water vapour from the Atlantic and Southern Ocean. Furthermore, simultaneous measurements of SWIs at two altitudes are used to illustrate the potential of such measurements for future research to estimate sea spray evaporation and turbulent moisture fluxes.
Philipp Zschenderlein, Stephan Pfahl, Heini Wernli, and Andreas H. Fink
Weather Clim. Dynam., 1, 191–206,Short summary
We analyse the formation of upper-tropospheric anticyclones connected to European surface heat waves. Tracing air masses backwards from these anticyclones, we found that trajectories are diabatically heated in two branches, either by North Atlantic cyclones or by convection closer to the heat wave anticyclone. The first branch primarily affects the onset of the anticyclone, while the second branch is more relevant for the maintenance. Our results are relevant for heat wave predictions.
Annika Oertel, Maxi Boettcher, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 127–153,Short summary
Warm conveyor belts (WCBs) are important, mainly stratiform cloud forming airstreams in extratropical cyclones that can include embedded convection. This WCB case study systematically compares the characteristics of convective vs. slantwise ascent of the WCB. We find that embedded convection leads to regions of significantly stronger precipitation. Moreover, it strongly modifies the potential vorticity distribution in the lower and upper troposphere, where its also influences the waveguide.
Dan Li, Bärbel Vogel, Rolf Müller, Jianchun Bian, Gebhard Günther, Felix Ploeger, Qian Li, Jinqiang Zhang, Zhixuan Bai, Holger Vömel, and Martin Riese
Atmos. Chem. Phys., 20, 4133–4152,Short summary
Low ozone and low water vapour signatures in the UTLS were investigated using balloon-borne measurements and trajectory calculations. The results show that deep convection in tropical cyclones over the western Pacific transports boundary air parcels with low ozone into the tropopause region. Subsequently, these air parcels are dehydrated when passing the lowest temperature region (< 190 K) during quasi-horizontal advection.
Sabine Griessbach, Lars Hoffmann, Reinhold Spang, Peggy Achtert, Marc von Hobe, Nina Mateshvili, Rolf Müller, Martin Riese, Christian Rolf, Patric Seifert, and Jean-Paul Vernier
Atmos. Meas. Tech., 13, 1243–1271,Short summary
In this paper we study the cloud top height derived from MIPAS measurements. Previous studies showed contradictory results with respect to MIPAS, both underestimating and overestimating cloud top height. We used simulations and found that overestimation and/or underestimation depend on cloud extinction. To support our findings we compared MIPAS cloud top heights of volcanic sulfate aerosol with measurements from CALIOP, ground-based lidar, and ground-based twilight measurements.
Matthias Röthlisberger, Michael Sprenger, Emmanouil Flaounas, Urs Beyerle, and Heini Wernli
Weather Clim. Dynam., 1, 45–62,Short summary
In this study we quantify how much the coldest, middle and hottest third of all days during extremely hot summers contribute to their respective seasonal mean anomaly. This
extreme-summer substructurevaries substantially across the Northern Hemisphere and is directly related to the local physical drivers of extreme summers. Furthermore, comparing re-analysis (i.e. measurement-based) and climate model extreme-summer substructures reveals a remarkable level of agreement.
Xiaolu Yan, Paul Konopka, Felix Ploeger, Aurélien Podglajen, Jonathon S. Wright, Rolf Müller, and Martin Riese
Atmos. Chem. Phys., 19, 15629–15649,Short summary
The Asian and North American summer monsoons (ASM and NASM) have considerable influence on stratospheric chemistry and physics. More air mass is transported from the monsoon regions to the tropical stratosphere when the tracers are released clearly below the tropopause than when they are released close to the tropopause. Results for different altitudes of air origin reveal two transport pathways (monsoon and tropical) from the upper troposphere over the monsoon regions to the tropical pipe.
Suvarna Fadnavis, Rolf Müller, Gayatry Kalita, Matthew Rowlinson, Alexandru Rap, Jui-Lin Frank Li, Blaž Gasparini, and Anton Laakso
Atmos. Chem. Phys., 19, 9989–10008,Short summary
This paper highlights the impact of Asian anthropogenic emission changes in SO2 on sulfate loading in the Asian upper troposphere–lower stratosphere from a global chemistry–climate model and satellite remote sensing. Estimated seasonal mean direct radiative forcing at the top of the atmosphere induced by the increase in Indian SO2 is −0.2–−1.5 W m2 over India. Chinese SO2 emission reduction leads to a positive radiative forcing of ~0.6–6 W m2 over China. It will likely decrease Indian rainfall.
Paul Konopka, Mengchu Tao, Felix Ploeger, Mohamadou Diallo, and Martin Riese
Geosci. Model Dev., 12, 2441–2462,Short summary
CLaMS is a Lagrangian transport model suitable for simulating atmospheric transport and chemistry. The novel approach of CLaMS is its description of atmospheric mixing. Whereas the common approach is to minimize the numerical diffusion ever present in the modeling of transport, CLaMS is a first attempt to apply this
undesirable disturbing effectto parametrize the true physical mixing. In this paper, we show how this concept works both in the stratosphere and in the troposphere.
Bojan Škerlak, Stephan Pfahl, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 19, 6535–6549,Short summary
Upper-level fronts are often associated with the rapid transport of stratospheric air to the lower troposphere, leading to significantly enhanced ozone concentrations. This paper considers the multi-scale nature that is needed to bring stratospheric air down to the surface. The final transport step to the surface can be related to frontal zones and the associated vertical winds or to near-horizontal tracer transport followed by entrainment into a growing planetary boundary layer.
Mengchu Tao, Paul Konopka, Felix Ploeger, Xiaolu Yan, Jonathon S. Wright, Mohamadou Diallo, Stephan Fueglistaler, and Martin Riese
Atmos. Chem. Phys., 19, 6509–6534,Short summary
This paper examines the annual and interannual variations as well as long-term trend of modeled stratospheric water vapor with a Lagrangian chemical transport model driven by ERA-I, MERRA-2 and JRA-55. We find reasonable consistency among the annual cycle, QBO and the variabilities induced by ENSO and volcanic aerosols. The main discrepancies are linked to the differences in reanalysis upwelling rates in the lower stratosphere. The trends are sensitive to the reanalyses that drives the model.
Bärbel Vogel, Rolf Müller, Gebhard Günther, Reinhold Spang, Sreeharsha Hanumanthu, Dan Li, Martin Riese, and Gabriele P. Stiller
Atmos. Chem. Phys., 19, 6007–6034,Short summary
We identified the transport pathways of air masses from the region of the Asian monsoon (e.g. pollution and greenhouse gases caused by increasing population and growing industries in Asia) into the lower stratosphere. Even small changes of the chemical composition of the lower stratosphere have an impact on surface climate (e.g. surface temperatures). Therefore, it is important to identify transport pathways to the stratosphere to allow potential environmental risks to be assessed.
Felix Ploeger, Bernard Legras, Edward Charlesworth, Xiaolu Yan, Mohamadou Diallo, Paul Konopka, Thomas Birner, Mengchu Tao, Andreas Engel, and Martin Riese
Atmos. Chem. Phys., 19, 6085–6105,Short summary
We analyse the change in the circulation of the middle atmosphere based on current generation meteorological reanalysis data sets. We find that long-term changes from 1989 to 2015 are similar for the chosen reanalyses, mainly resembling the forced response in climate model simulations to climate change. For shorter periods circulation changes are less robust, and the representation of decadal variability appears to be a major uncertainty for modelling the circulation of the middle atmosphere.
Sabine Robrecht, Bärbel Vogel, Jens-Uwe Grooß, Karen Rosenlof, Troy Thornberry, Andrew Rollins, Martina Krämer, Lance Christensen, and Rolf Müller
Atmos. Chem. Phys., 19, 5805–5833,Short summary
The potential destruction of stratospheric ozone in the mid-latitudes has been discussed recently. We analysed this ozone loss mechanism and its sensitivities. In a certain temperature range, we found a threshold in water vapour, which has to be exceeded for ozone loss to occur. We show the dependence of this water vapour threshold on temperature, sulfate content and air composition. This study provides a basis to estimate the impact of potential sulphate geoengineering on stratospheric ozone.
Lars Hoffmann, Gebhard Günther, Dan Li, Olaf Stein, Xue Wu, Sabine Griessbach, Yi Heng, Paul Konopka, Rolf Müller, Bärbel Vogel, and Jonathon S. Wright
Atmos. Chem. Phys., 19, 3097–3124,Short summary
ECMWF's new ERA5 reanalysis provides higher spatiotemporal resolution, yielding an improved representation of meso- and synoptic-scale features of the atmosphere. We assessed the impact of this challenging new data set on Lagrangian trajectory calculations for the free troposphere and stratosphere. Key findings are considerable transport deviations between the ERA5 and ERA-Interim simulations as well as significantly improved conservation of potential temperature in the stratosphere for ERA5.
Pascal Graf, Heini Wernli, Stephan Pfahl, and Harald Sodemann
Atmos. Chem. Phys., 19, 747–765,Short summary
This article studies the interaction between falling rain and vapour with stable water isotopes. In particular, rain evaporation is relevant for several atmospheric processes, but remains difficult to quantify. A novel framework is introduced to facilitate the interpretation of stable water isotope observations in near-surface vapour and rain. The usefulness of this concept is demonstrated using observations at high time resolution from a cold front. Sensitivities are tested with a simple model.
Ines Tritscher, Jens-Uwe Grooß, Reinhold Spang, Michael C. Pitts, Lamont R. Poole, Rolf Müller, and Martin Riese
Atmos. Chem. Phys., 19, 543–563,Short summary
We present Lagrangian simulations of polar stratospheric clouds (PSCs) for the Arctic winter 2009/2010 and the Antarctic winter 2011 using the Chemical Lagrangian Model of the Stratosphere (CLaMS). The paper comprises a detailed model description with ice PSCs and related dehydration being the focus of this study. Comparisons between our simulations and observations from different satellites on season-long and vortex-wide scales as well as for single PSC events show an overall good agreement.
Mohamadou Diallo, Paul Konopka, Michelle L. Santee, Rolf Müller, Mengchu Tao, Kaley A. Walker, Bernard Legras, Martin Riese, Manfred Ern, and Felix Ploeger
Atmos. Chem. Phys., 19, 425–446,Short summary
This paper assesses the structural changes in the shallow and transition branches of the BDC induced by El Nino using the Lagrangian model simulations driven by ERAi and JRA-55 combined with MLS observations. We found a clear evidence of a weakening of the transition branch due to an upward shift in the dissipation height of the planetary and gravity waves and a strengthening of the shallow branch due to enhanced GW breaking in the tropics–subtropics and PW breaking at high latitudes.
Dan Li, Bärbel Vogel, Rolf Müller, Jianchun Bian, Gebhard Günther, Qian Li, Jinqiang Zhang, Zhixuan Bai, Holger Vömel, and Martin Riese
Atmos. Chem. Phys., 18, 17979–17994,Short summary
Balloon-borne measurements performed over Lhasa in August 2013 are investigated using CLaMS trajectory calculations. Here, we focus on high ozone mixing ratios in the free troposphere. Our findings demonstrate that both stratospheric intrusions and convective transport of air pollution play a major role in enhancing middle and upper tropospheric ozone.
Annette Filges, Christoph Gerbig, Chris W. Rella, John Hoffnagle, Herman Smit, Martina Krämer, Nicole Spelten, Christian Rolf, Zoltán Bozóki, Bernhard Buchholz, and Volker Ebert
Atmos. Meas. Tech., 11, 5279–5297,
Mohamadou Diallo, Martin Riese, Thomas Birner, Paul Konopka, Rolf Müller, Michaela I. Hegglin, Michelle L. Santee, Mark Baldwin, Bernard Legras, and Felix Ploeger
Atmos. Chem. Phys., 18, 13055–13073,Short summary
The unprecedented timing of an El Niño event aligned with the disrupted QBO in 2015–2016 caused a perturbation to the stratospheric circulation, affecting trace gases. This paper resolves the puzzling response of the lower stratospheric water vapor by showing that the QBO disruption reversed the lower stratosphere moistening triggered by the alignment of the El Niño event with a westerly QBO in early boreal winter.
Suvarna Fadnavis, Chaitri Roy, Rajib Chattopadhyay, Christopher E. Sioris, Alexandru Rap, Rolf Müller, K. Ravi Kumar, and Raghavan Krishnan
Atmos. Chem. Phys., 18, 11493–11506,Short summary
Rapid industrialization, traffic growth and urbanization resulted in a significant increase in the tropospheric trace gases over Asia. There is global concern about rising levels of these trace gases. The monsoon convection transports these gases to the upper-level-anticyclone. In this study, we show transport of these gases to the extratropics via eddy-shedding from the anticyclone. We also deliberate on changes in ozone heating rates due to the transport of Asian trace gases.
Armin Afchine, Christian Rolf, Anja Costa, Nicole Spelten, Martin Riese, Bernhard Buchholz, Volker Ebert, Romy Heller, Stefan Kaufmann, Andreas Minikin, Christiane Voigt, Martin Zöger, Jessica Smith, Paul Lawson, Alexey Lykov, Sergey Khaykin, and Martina Krämer
Atmos. Meas. Tech., 11, 4015–4031,Short summary
The ice water content (IWC) of cirrus clouds is an essential parameter that determines their radiative properties and is thus important for climate simulations. Experimental investigations of IWCs measured on board research aircraft reveal that their accuracy is influenced by the sampling position. IWCs detected at the aircraft roof deviate significantly from wing, side or bottom IWCs. The reasons are deflections of the gas streamlines and ice particle trajectories behind the aircraft cockpit.
Jens-Uwe Grooß, Rolf Müller, Reinhold Spang, Ines Tritscher, Tobias Wegner, Martyn P. Chipperfield, Wuhu Feng, Douglas E. Kinnison, and Sasha Madronich
Atmos. Chem. Phys., 18, 8647–8666,Short summary
We investigate a discrepancy between model simulations and observations of HCl in the dark polar stratosphere. In early winter, the less-well-studied period of the onset of chlorine activation, observations show a much faster depletion of HCl than simulations of three models. This points to some unknown process that is currently not represented in the models. Various hypotheses for potential causes are investigated that partly reduce the discrepancy. The impact on polar ozone depletion is low.
Liubov Poshyvailo, Rolf Müller, Paul Konopka, Gebhard Günther, Martin Riese, Aurélien Podglajen, and Felix Ploeger
Atmos. Chem. Phys., 18, 8505–8527,Short summary
Water vapour (H2O) in the UTLS is a key player for global radiation, which is critical for predictions of future climate change. We investigate the effects of current uncertainties in tropopause temperature, horizontal transport and small-scale mixing on simulated H2O, using the Chemical Lagrangian Model of the Stratosphere. Our sensitivity studies provide new insights into the leading processes controlling stratospheric H2O, important for assessing and improving climate model projections.
Xiaolu Yan, Paul Konopka, Felix Ploeger, Mengchu Tao, Rolf Müller, Michelle L. Santee, Jianchun Bian, and Martin Riese
Atmos. Chem. Phys., 18, 8079–8096,Short summary
Many works investigate the impact of ENSO on the troposphere. However, only a few works check the impact of ENSO at higher altitudes. Here, we analyse the impact of ENSO on the vicinity of the tropopause using reanalysis, satellite, in situ and model data. We find that ENSO shows the strongest signal in winter, but its impact can last until early the next summer. The ENSO anomaly is insignificant in late summer. Our study can help to understand the atmosphere propagation after ENSO.
Reinhold Spang, Lars Hoffmann, Rolf Müller, Jens-Uwe Grooß, Ines Tritscher, Michael Höpfner, Michael Pitts, Andrew Orr, and Martin Riese
Atmos. Chem. Phys., 18, 5089–5113,Short summary
This paper represents an unprecedented pole-covering day- and nighttime climatology of the polar stratospheric clouds (PSCs) based on satellite measurements, their spatial distribution, and composition of different particle types. The climatology has a high potential for the validation and improvement of PSC schemes in chemical transport and chemistry–climate models, which is important for a better prediction of future polar ozone loss in a changing climate.
Rolf Müller, Jens-Uwe Grooß, Abdul Mannan Zafar, Sabine Robrecht, and Ralph Lehmann
Atmos. Chem. Phys., 18, 2985–2997,Short summary
This paper revisits the chemistry leading to strong ozone depletion in the Antarctic. We focus on the heart of the ozone layer in the lowermost stratosphere in the core of the vortex. We argue that chemical cycles (referred to as HCl null cycles) that have hitherto been largely neglected counteract the deactivation of chlorine and are therefore key to ozone depletion in the core of the Antarctic vortex. The key process to full activation of chlorine is the photolysis of formaldehyde.
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.
Marina Dütsch, Stephan Pfahl, Miro Meyer, and Heini Wernli
Atmos. Chem. Phys., 18, 1653–1669,Short summary
Atmospheric processes are imprinted in the concentrations of stable water isotopes. Therefore, isotopes can be used to gain insight into these processes and improve our understanding of the water cycle. In this study, we present a new method that quantitatively shows which atmospheric processes influence isotope concentrations in near-surface water vapour over Europe. We found that the most important processes are evaporation from the ocean, evapotranspiration from land, and turbulent mixing.
Florian Berkes, Patrick Neis, Martin G. Schultz, Ulrich Bundke, Susanne Rohs, Herman G. J. Smit, Andreas Wahner, Paul Konopka, Damien Boulanger, Philippe Nédélec, Valerie Thouret, and Andreas Petzold
Atmos. Chem. Phys., 17, 12495–12508,Short summary
This study highlights the importance of independent global measurements with high and long-term accuracy to quantify long-term changes, especially in the UTLS region, and to help identify inconsistencies between different data sets of observations and models. Here we investigated temperature trends over different regions within a climate-sensitive area of the atmosphere and demonstrated the value of the IAGOS temperature observations as an anchor point for the evaluation of reanalyses.
Felix Ploeger, Paul Konopka, Kaley Walker, and Martin Riese
Atmos. Chem. Phys., 17, 7055–7066,Short summary
Pollution transport from the surface to the stratosphere within the Asian summer monsoon circulation may cause harmful effects on stratospheric chemistry and climate. We investigate air mass transport from the monsoon anticyclone into the stratosphere, combining model simulations with satellite trace gas measurements. We show evidence for two transport pathways from the monsoon: (i) into the tropical stratosphere and (ii) into the Northern Hemisphere extratropical lower stratosphere.
Hanna Joos, Erica Madonna, Kasja Witlox, Sylvaine Ferrachat, Heini Wernli, and Ulrike Lohmann
Atmos. Chem. Phys., 17, 6243–6255,Short summary
The influence of pollution on the precipitation formation in warm conveyor belts (WCBs), the most rising air streams in low-pressure systems is investigated. We investigate in detail the cloud properties and resulting precipitation along these rising airstreams which are simulated with a global climate model. Overall, no big impact of aerosols on precipitation can be seen, however, when comparing the most polluted/cleanest WCBs, a suppression of precipitation by aerosols is observed.
Harald Sodemann, Franziska Aemisegger, Stephan Pfahl, Mark Bitter, Ulrich Corsmeier, Thomas Feuerle, Pascal Graf, Rolf Hankers, Gregor Hsiao, Helmut Schulz, Andreas Wieser, and Heini Wernli
Atmos. Chem. Phys., 17, 6125–6151,Short summary
We report here the first survey of stable water isotope composition over the Mediterranean sea made from aircraft. The stable isotope composition of the atmospheric water vapour changed in response to evaporation conditions at the sea surface, elevation, and airmass transport history. Our data set will be valuable for testing how water is transported in weather prediction and climate models and for understanding processes in the Mediterranean water cycle.
Dan Li, Bärbel Vogel, Jianchun Bian, Rolf Müller, Laura L. Pan, Gebhard Günther, Zhixuan Bai, Qian Li, Jinqiang Zhang, Qiujun Fan, and Holger Vömel
Atmos. Chem. Phys., 17, 4657–4672,Short summary
High-resolution ozone and water vapour profiles over Lhasa, China, were measured in August 2013. The correlations between ozone and water vapour profiles show a strong variability in the upper troposphere. These relationships were investigated using CLaMS trajectory calculations. The model results demonstrate that three tropical cyclones (Jebi, Utor, and Trami), occurring over the western Pacific, had a strong impact on the vertical structure of ozone and water vapour profiles.
Chaitri Roy, Suvarna Fadnavis, Rolf Müller, D. C. Ayantika, Felix Ploeger, and Alexandru Rap
Atmos. Chem. Phys., 17, 1297–1311,Short summary
In the monsoon season, Asian NOx emissions are rapidly transported to the UTLS and can impact ozone in the UTLS. From chemistry–climate model simulations, we show that increasing Asian NOx emissions have enhanced ozone radiative forcing over Southeast Asia, which leads to significant warming over the Tibetan Plateau and increase precipitation over India. However, a further increase in NOx emissions elicited negative precipitation due to reversal of monsoon Hadley circulation.
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.
Sabine Griessbach, Lars Hoffmann, Reinhold Spang, Marc von Hobe, Rolf Müller, and Martin Riese
Atmos. Meas. Tech., 9, 4399–4423,Short summary
A new method for detecting aerosol in the UTLS based on infrared limb emission measurements is presented. The method was developed using radiative transfer simulations (including scattering) and Envisat MIPAS measurements. Results are presented for volcanic ash and sulfate aerosol originating from the Grimsvötn (Iceland), Puyehue–Cordon Caulle (Chile), and Nabro (Eritrea) eruptions in 2011 and compared with AIRS volcanic ash and SO2 measurements.
Reinhold Spang, Lars Hoffmann, Michael Höpfner, Sabine Griessbach, Rolf Müller, Michael C. Pitts, Andrew M. W. Orr, and Martin Riese
Atmos. Meas. Tech., 9, 3619–3639,Short summary
We present a new classification approach for different polar stratospheric cloud types. The so-called Bayesian classifier estimates the most likely probability that one of the three PSC types (ice, NAT, or STS) dominates the characteristics of a measured infrared spectrum. The entire measurement period of the satellite instrument MIPAS from July 2002 to April 2013 is processed using the new classifier.
Jörn Ungermann, Mandfred Ern, Martin Kaufmann, Rolf Müller, Reinhold Spang, Felix Ploeger, Bärbel Vogel, and Martin Riese
Atmos. Chem. Phys., 16, 8389–8403,Short summary
This paper presents an analysis of temperature and the trace gases PAN and O3 in the Asian Summer Monsoon (ASM) region. The positive PAN anomaly consisting of polluted air is confined vertically within the main ASM anticyclone, whereas a recently shed eddy exhibits enhanced PAN VMRs for 1 to 2 km above the thermal tropopause. This implies that eddy shedding provides a very rapid horizontal transport pathway of Asian pollution into the extratropical lowermost stratosphere.
Charlotte Marinke Hoppe, Felix Ploeger, Paul Konopka, and Rolf Müller
Atmos. Chem. Phys., 16, 6223–6239,
Anna E. Luebke, Armin Afchine, Anja Costa, Jens-Uwe Grooß, Jessica Meyer, Christian Rolf, Nicole Spelten, Linnea M. Avallone, Darrel Baumgardner, and Martina Krämer
Atmos. Chem. Phys., 16, 5793–5809,Short summary
In this study, we present observational evidence to show that two distinct types of cirrus clouds exist – in situ origin and liquid origin cirrus. These two types differ by their formation mechanism and other properties. Airborne, in-cloud measurements of cloud ice water content (IWC), ice crystal concentration (Nice), and ice crystal size from the 2014 ML-CIRRUS campaign provide cloud samples that have been divided and analyzed according to their origin type.
Martina Krämer, Christian Rolf, Anna Luebke, Armin Afchine, Nicole Spelten, Anja Costa, Jessica Meyer, Martin Zöger, Jessica Smith, Robert L. Herman, Bernhard Buchholz, Volker Ebert, Darrel Baumgardner, Stephan Borrmann, Marcus Klingebiel, and Linnea Avallone
Atmos. Chem. Phys., 16, 3463–3483,Short summary
A guide to cirrus clouds is compiled from extensive model simulations and aircraft observations. Two types of cirrus are found: rather thin in situ cirrus that form directly as ice and thicker liquid origin cirrus consisting of uplifted frozen liquid drops. Over Europe, thinner in situ and liquid origin cirrus occur often together with frontal systems, while over the US and the Tropics, thick liquid origin cirrus formed in large convective systems are detected more frequently.
K. Weigel, A. Rozanov, F. Azam, K. Bramstedt, R. Damadeo, K.-U. Eichmann, C. Gebhardt, D. Hurst, M. Kraemer, S. Lossow, W. Read, N. Spelten, G. P. Stiller, K. A. Walker, M. Weber, H. Bovensmann, and J. P. Burrows
Atmos. Meas. Tech., 9, 133–158,Short summary
The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) aboard the Envisat satellite provided measurements between 2002 and 2012 with different viewing geometries. The limb viewing geometry allows the retrieval of water vapour profiles in the UTLS (upper troposphere and lower stratosphere) from the near-infrared spectral range (1353–1410 nm). Here, we present data version 3.01 and compare it to other water vapour data.
B. Vogel, G. Günther, R. Müller, J.-U. Grooß, and M. Riese
Atmos. Chem. Phys., 15, 13699–13716,Short summary
The Asian summer monsoon circulation is an important global circulation system associated with strong upward transport of tropospheric source gases. We show that the contribution of different boundary source regions to the Asian monsoon anticyclone strongly depends on its intra-seasonal variability and that emissions from Asia have a significant impact on the chemical compositions of the lowermost stratosphere of the Northern Hemisphere at the end of the monsoon season in Sep./Oct. 2012.
F. Ploeger, C. Gottschling, S. Griessbach, J.-U. Grooß, G. Guenther, P. Konopka, R. Müller, M. Riese, F. Stroh, M. Tao, J. Ungermann, B. Vogel, and M. von Hobe
Atmos. Chem. Phys., 15, 13145–13159,Short summary
The Asian summer monsoon provides an important pathway of tropospheric source gases and pollution into the lower stratosphere. This transport is characterized by deep convection and steady upwelling, combined with confinement inside a large-scale anticyclonic circulation in the upper troposphere and lower stratosphere. In this paper, we show that a barrier to horizontal transport in the monsoon can be determined from a local maximum in the gradient of potential vorticity.
P. Reutter, B. Škerlak, M. Sprenger, and H. Wernli
Atmos. Chem. Phys., 15, 10939–10953,Short summary
In this manuscript, we investigate the exchange of air masses across the dynamical tropopause (stratosphere-troposphere exchange, STE) in the vicinity of North Atlantic cyclones. By using two 6-hourly resolved ERA-Interim climatologies of STE and cyclones from 1979 to 2011, we are able to directly compute the amount of STE in the vicinity of every individual cyclone in this time period. This enables us to provide a robust and consistent quantification of STE near North Atlantic cyclones.
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,
M. Sprenger and H. Wernli
Geosci. Model Dev., 8, 2569–2586,
M. Tao, P. Konopka, F. Ploeger, J.-U. Grooß, R. Müller, C. M. Volk, K. A. Walker, and M. Riese
Atmos. Chem. Phys., 15, 8695–8715,Short summary
A remarkable major stratospheric sudden warming during the boreal winter 2008/09 is studied with the Chemical Lagrangian Model of the Stratosphere (CLaMS). We investigate how mixing triggered by this event correlates the wave forcing and how transport and mixing affect the composition of the whole stratosphere in the Northern Hemisphere, by using the tracer-tracer correlation technique.
J. Meyer, C. Rolf, C. Schiller, S. Rohs, N. Spelten, A. Afchine, M. Zöger, N. Sitnikov, T. D. Thornberry, A. W. Rollins, Z. Bozóki, D. Tátrai, V. Ebert, B. Kühnreich, P. Mackrodt, O. Möhler, H. Saathoff, K. H. Rosenlof, and M. Krämer
Atmos. Chem. Phys., 15, 8521–8538,
P. Neis, H. G. J. Smit, M. Krämer, N. Spelten, and A. Petzold
Atmos. Meas. Tech., 8, 1233–1243,
O. Kirner, R. Müller, R. Ruhnke, and H. Fischer
Atmos. Chem. Phys., 15, 2019–2030,Short summary
We use multi-year simulations of the chemistry--climate model EMAC to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. Heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring in the model simulations. In high southern latitudes, heterogeneous chemistry on ice particles causes only up to 5 DU of additional ozone depletion and chemistry on NAT particles less than 0.5 DU.
R. Spang, G. Günther, M. Riese, L. Hoffmann, R. Müller, and S. Griessbach
Atmos. Chem. Phys., 15, 927–950,Short summary
Here we present observations of the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) of cirrus cloud and water vapour in August 1997 in the upper troposphere and lower stratosphere (UTLS) region. The observations indicate a considerable flux of moisture from the upper tropical troposphere into the extra-tropical lowermost stratosphere (LMS), resulting in the occurrence of high-altitude optically thin cirrus clouds in the LMS.
D. Tátrai, Z. Bozóki, H. Smit, C. Rolf, N. Spelten, M. Krämer, A. Filges, C. Gerbig, G. Gulyás, and G. Szabó
Atmos. Meas. Tech., 8, 33–42,Short summary
Airborne hygrometry is very important in climate research, and the interest in knowing not only water vapor concentration but (cirrus) cloud content as well is increasing. The authors provide a photoacoustic spectroscopy-based dual-channel hygrometer system that can be a good solution for such measurements. The instrument was proven to operate properly from ground level up to the lower stratosphere, giving the possibility even for cirrus cloud studies.
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.
L. Hoffmann, C. M. Hoppe, R. Müller, G. S. Dutton, J. C. Gille, S. Griessbach, A. Jones, C. I. Meyer, R. Spang, C. M. Volk, and K. A. Walker
Atmos. Chem. Phys., 14, 12479–12497,Short summary
Stratospheric lifetimes determine the global warming and ozone depletion potentials of chlorofluorocarbons. We present new estimates of the CFC-11/CFC-12 lifetime ratio from satellite and model data (ACE-FTS, HIRDLS, MIPAS, and EMAC/CLaMS). Our estimates of 0.46+/-0.04 (satellites) and 0.48+/-0.07 (model) are in excellent agreement with the recent SPARC reassessment. Having smaller uncertainties than other studies, our results can help to better constrain future CFC lifetime recommendations.
C. M. Hoppe, L. Hoffmann, P. Konopka, J.-U. Grooß, F. Ploeger, G. Günther, P. Jöckel, and R. Müller
Geosci. Model Dev., 7, 2639–2651,
S. Molleker, S. Borrmann, H. Schlager, B. Luo, W. Frey, M. Klingebiel, R. Weigel, M. Ebert, V. Mitev, R. Matthey, W. Woiwode, H. Oelhaf, A. Dörnbrack, G. Stratmann, J.-U. Grooß, G. Günther, B. Vogel, R. Müller, M. Krämer, J. Meyer, and F. Cairo
Atmos. Chem. Phys., 14, 10785–10801,
D. W. Fahey, R.-S. Gao, O. Möhler, H. Saathoff, C. Schiller, V. Ebert, M. Krämer, T. Peter, N. Amarouche, L. M. Avallone, R. Bauer, Z. Bozóki, L. E. Christensen, S. M. Davis, G. Durry, C. Dyroff, R. L. Herman, S. Hunsmann, S. M. Khaykin, P. Mackrodt, J. Meyer, J. B. Smith, N. Spelten, R. F. Troy, H. Vömel, S. Wagner, and F. G. Wienhold
Atmos. Meas. Tech., 7, 3177–3213,
M. S. Johnston, S. Eliasson, P. Eriksson, R. M. Forbes, A. Gettelman, P. Räisänen, and M. D. Zelinka
Atmos. Chem. Phys., 14, 8701–8721,
P. Reutter, J. Trentmann, A. Seifert, P. Neis, H. Su, D. Chang, M. Herzog, H. Wernli, M. O. Andreae, and U. Pöschl
Atmos. Chem. Phys., 14, 7573–7583,
C. M. Grams, H. Binder, S. Pfahl, N. Piaget, and H. Wernli
Nat. Hazards Earth Syst. Sci., 14, 1691–1702,
A. Winschall, S. Pfahl, H. Sodemann, and H. Wernli
Atmos. Chem. Phys., 14, 6605–6619,
F. Aemisegger, S. Pfahl, H. Sodemann, I. Lehner, S. I. Seneviratne, and H. Wernli
Atmos. Chem. Phys., 14, 4029–4054,
J.-U. Grooß, I. Engel, S. Borrmann, W. Frey, G. Günther, C. R. Hoyle, R. Kivi, B. P. Luo, S. Molleker, T. Peter, M. C. Pitts, H. Schlager, G. Stiller, H. Vömel, K. A. Walker, and R. Müller
Atmos. Chem. Phys., 14, 1055–1073,
B. Škerlak, M. Sprenger, and H. Wernli
Atmos. Chem. Phys., 14, 913–937,
M. S. Johnston, S. Eliasson, P. Eriksson, R. M. Forbes, K. Wyser, and M. D. Zelinka
Atmos. Chem. Phys., 13, 12043–12058,
S. M. Khaykin, I. Engel, H. Vömel, I. M. Formanyuk, R. Kivi, L. I. Korshunov, M. Krämer, A. D. Lykov, S. Meier, T. Naebert, M. C. Pitts, M. L. Santee, N. Spelten, F. G. Wienhold, V. A. Yushkov, and T. Peter
Atmos. Chem. Phys., 13, 11503–11517,
A. K. Miltenberger, S. Pfahl, and H. Wernli
Geosci. Model Dev., 6, 1989–2004,
C. Frick, A. Seifert, and H. Wernli
Geosci. Model Dev., 6, 1925–1939,
M. Abalos, F. Ploeger, P. Konopka, W. J. Randel, and E. Serrano
Atmos. Chem. Phys., 13, 10787–10794,
M. von Hobe, S. Bekki, S. Borrmann, F. Cairo, F. D'Amato, G. Di Donfrancesco, A. Dörnbrack, A. Ebersoldt, M. Ebert, C. Emde, I. Engel, M. Ern, W. Frey, S. Genco, S. Griessbach, J.-U. Grooß, T. Gulde, G. Günther, E. Hösen, L. Hoffmann, V. Homonnai, C. R. Hoyle, I. S. A. Isaksen, D. R. Jackson, I. M. Jánosi, R. L. Jones, K. Kandler, C. Kalicinsky, A. Keil, S. M. Khaykin, F. Khosrawi, R. Kivi, J. Kuttippurath, J. C. Laube, F. Lefèvre, R. Lehmann, S. Ludmann, B. P. Luo, M. Marchand, J. Meyer, V. Mitev, S. Molleker, R. Müller, H. Oelhaf, F. Olschewski, Y. Orsolini, T. Peter, K. Pfeilsticker, C. Piesch, M. C. Pitts, L. R. Poole, F. D. Pope, F. Ravegnani, M. Rex, M. Riese, T. Röckmann, B. Rognerud, A. Roiger, C. Rolf, M. L. Santee, M. Scheibe, C. Schiller, H. Schlager, M. Siciliani de Cumis, N. Sitnikov, O. A. Søvde, R. Spang, N. Spelten, F. Stordal, O. Sumińska-Ebersoldt, A. Ulanovski, J. Ungermann, S. Viciani, C. M. Volk, M. vom Scheidt, P. von der Gathen, K. Walker, T. Wegner, R. Weigel, S. Weinbruch, G. Wetzel, F. G. Wienhold, I. Wohltmann, W. Woiwode, I. A. K. Young, V. Yushkov, B. Zobrist, and F. Stroh
Atmos. Chem. Phys., 13, 9233–9268,
K. Minschwaner, L. Hoffmann, A. Brown, M. Riese, R. Müller, and P. F. Bernath
Atmos. Chem. Phys., 13, 4253–4263,
F. Khosrawi, R. Müller, J. Urban, M. H. Proffitt, G. Stiller, M. Kiefer, S. Lossow, D. Kinnison, F. Olschewski, M. Riese, and D. Murtagh
Atmos. Chem. Phys., 13, 3619–3641,
Related subject area
Subject: Gases | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)Evaluation of modelled climatologies of O3, CO, water vapour and NOy in the upper troposphere–lower stratosphere using regular in situ observations by passenger aircraftPhotochemical ageing of aerosols contributes significantly to the production of atmospheric formic acidNitrous acid budgets in the coastal atmosphere: potential daytime marine sourcesUndetected biogenic volatile organic compounds from Norway spruce drive total ozone reactivity measurementsQuantification of fossil fuel CO2 from combined CO, δ13CO2 and Δ14CO2 observationsRadical chemistry and ozone production at a UK coastal receptor siteSources and long-term variability of carbon monoxide at Mount Kenya and in NairobiMeasurement report: Airborne measurements of NOx fluxes over Los Angeles during the RECAP-CA 2021 campaignInfluence of anthropogenic emissions on the composition of highly oxygenated organic molecules in Helsinki: a street canyon and urban background station comparisonChanges in surface ozone in South Korea on diurnal to decadal timescales for the period of 2001–2021Characterization of the nitrogen stable isotope composition (δ15N) of ship-emitted NOxVolatile organic compound fluxes in the agricultural San Joaquin Valley – spatial distribution, source attribution, and inventory comparisonExploring the amplified role of HCHO in the formation of HMS and O3 during the co-occurring PM2.5 and O3 pollution in a coastal city of southeast ChinaHigh potential for CH4 emission mitigation from oil infrastructure in one of EU's major production regionsMeasurement report: Source apportionment and environmental impacts of volatile organic compounds (VOCs) in Lhasa, a highland city in ChinaOH, HO2, and RO2 radical chemistry in a rural forest environment: measurements, model comparisons, and evidence of a missing radical sinkThe atmospheric fate of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH): spatial patterns, seasonal variability, and deposition to Canadian coastal regionsA single-point modeling approach for the intercomparison and evaluation of ozone dry deposition across chemical transport models (Activity 2 of AQMEII4)Direct observations of NOx emissions over the San Joaquin Valley using airborne flux measurements during RECAP-CA 2021 field campaignTrends and seasonal variability in ammonia across major biomes in western and central Africa inferred from long-term series of ground-based and satellite measurementsA rise in HFC-23 emissions from eastern Asia since 2015The interhemispheric gradient of SF6 in the upper troposphereMeasurement report: Inland ship emissions and their contribution to NOx and ultrafine particle concentrations at the RhineVariation and trend of nitrate radical reactivity towards volatile organic compounds in Beijing, ChinaMeasurement report: Atmospheric nitrate radical chemistry in the South China Sea influenced by the urban outflow of the Pearl River DeltaIntra- and interannual changes in isoprene emission from central AmazoniaLevels of persistent organic pollutants (POPs) in the Antarctic atmosphere over time (1980 to 2021) and estimation of their atmospheric half-livesAirborne observations of peroxy radicals during the EMeRGe campaign in EuropeVertical distribution of sources and sinks of volatile organic compounds within a boreal forest canopyO3 and PAN in southern Tibetan Plateau determined by distinct physical and chemical processesTechnical note: Isolating methane emissions from animal feeding operations in an interfering locationMeasurement Report: Exchange Fluxes of HONO over Agricultural Fields in the North China PlainHONO chemistry at a suburban site during the EXPLORE-YRD campaign in 2018: HONO formation mechanisms and impacts on O3 productionParameterizations of US wildfire and prescribed fire emission ratios and emission factors based on FIREX-AQ aircraft measurementsTropospheric Bromine Monoxide Vertical Profiles Retrieved Across the Alaskan Arctic in SpringtimeMeasurement report: Atmospheric CH4 at regional stations of the Korea Meteorological Administration–Global Atmosphere Watch Programme: measurement, characteristics, and long-term changes of its driversMeasurement report: MAX-DOAS measurements characterise Central London ozone pollution episodes during 2022 heatwavesWeather regimes and related atmospheric composition at a Pyrenean observatory characterized by hierarchical clustering of a 5-year data setOH measurements in the coastal atmosphere of South China: possible missing OH sinks in aged air massesSource attribution of methane emissions from the Upper Silesian Coal Basin, Poland, using isotopic signaturesMeasurement report: Underestimated reactive organic gases from residential combustion – insights from a near-complete speciationMeasurement Report: The Palau Atmospheric Observatory and its Ozonesonde Record - Continuous Monitoring of Tropospheric Composition and Dynamics in the Tropical West PacificMeasurement report: Hydrogen peroxide in the upper tropical troposphere over the Atlantic Ocean and western Africa during the CAFE-Africa aircraft campaignA new insight into the vertical differences in NO2 heterogeneous reaction to produce HONO over inland and marginal seasChemical identification of new particle formation and growth precursors through positive matrix factorization of ambient ion measurementsSnowpack nitrate photolysis drives the summertime atmospheric nitrous acid (HONO) budget in coastal AntarcticaRevealing the sources and sinks of negative cluster ions in an urban environment through quantitative analysisMeasurement report: Molecular-level investigation of atmospheric cluster ions at the tropical high-altitude research station Chacaltaya (5240 m a.s.l.) in the Bolivian AndesObservations of biogenic volatile organic compounds over a mixed temperate forest during the summer to autumn transitionUnexpectedly high concentrations of atmospheric mercury species in Lhasa, the largest city in the Tibetan Plateau
Yann Cohen, Didier Hauglustaine, Bastien Sauvage, Susanne Rohs, Patrick Konjari, Ulrich Bundke, Andreas Petzold, Valérie Thouret, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 23, 14973–15009,Short summary
The upper troposphere–lower stratosphere (UTLS) is a key region regarding the lower atmospheric composition. This study consists of a comprehensive evaluation of an up-to-date chemistry–climate model in this layer, using regular in situ measurements based on passenger aircraft. For this purpose, a specific software (Interpol-IAGOS) has been updated and made publicly available. The model reproduces the carbon monoxide peaks due to biomass burning over the continental tropics particularly well.
Yifan Jiang, Men Xia, Zhe Wang, Penggang Zheng, Yi Chen, and Tao Wang
Atmos. Chem. Phys., 23, 14813–14828,Short summary
This study provides the first estimate of high rates of formic acid (HCOOH) production from the photochemical aging of real ambient particles and demonstrates the potential importance of this pathway in the formation of HCOOH under ambient conditions. Incorporating this pathway significantly improved the performance of a widely used chemical model. Our solution irradiation experiments demonstrated the importance of nitrate photolysis in HCOOH production via the production of oxidants.
Xuelian Zhong, Hengqing Shen, Min Zhao, Ji Zhang, Yue Sun, Yuhong Liu, Yingnan Zhang, Ye Shan, Hongyong Li, Jiangshan Mu, Yu Yang, Yanqiu Nie, Jinghao Tang, Can Dong, Xinfeng Wang, Yujiao Zhu, Mingzhi Guo, Wenxing Wang, and Likun Xue
Atmos. Chem. Phys., 23, 14761–14778,Short summary
Nitrous acid (HONO) is vital for atmospheric oxidation. In research at Mount Lao, China, models revealed a significant unidentified marine HONO source. Overlooking this could skew our understanding of air quality and climate change. This finding emphasizes HONO’s importance in the coastal atmosphere, uncovering previously unnoticed interactions.
Steven Job Thomas, Toni Tykkä, Heidi Hellén, Federico Bianchi, and Arnaud P. Praplan
Atmos. Chem. Phys., 23, 14627–14642,Short summary
The study employed total ozone reactivity to demonstrate how emissions of Norway spruce readily react with ozone and could be a major ozone sink, particularly under stress. Additionally, this approach provided insight into the limitations of current analytical techniques that measure the compounds present or emitted into the atmosphere. The study shows how the technique used was not enough to measure all compounds emitted, and this could potentially underestimate various atmospheric processes.
Jinsol Kim, John B. Miller, Charles E. Miller, Scott J. Lehman, Sylvia E. Michel, Vineet Yadav, Nick E. Rollins, and William M. Berelson
Atmos. Chem. Phys., 23, 14425–14436,Short summary
In this study, we present the partitioning of CO2 signals from biogenic, petroleum and natural gas sources by combining CO, 13CO2 and 14CO2 measurements. Using measurements from flask air samples at three sites in the greater Los Angeles region, we find larger and positive contributions of biogenic signals in winter and smaller and negative contributions in summer. The largest contribution of natural gas combustion generally occurs in summer.
Robert Woodward-Massey, Roberto Sommariva, Lisa K. Whalley, Danny R. Cryer, Trevor Ingham, William J. Bloss, Stephen M. Ball, Sam Cox, James D. Lee, Chris P. Reed, Leigh R. Crilley, Louisa J. Kramer, Brian J. Bandy, Grant L. Forster, Claire E. Reeves, Paul S. Monks, and Dwayne E. Heard
Atmos. Chem. Phys., 23, 14393–14424,Short summary
Measurements of OH, HO2 and RO2 radicals and also OH reactivity were made at a UK coastal site and compared to calculations from a constrained box model utilising the Master Chemical Mechanism. The model agreement displayed a strong dependence on the NO concentration. An experimental budget analysis for OH, HO2, RO2 and total ROx demonstrated significant imbalances between HO2 and RO2 production rates. Ozone production rates were calculated from measured radicals and compared to modelled values.
Leonard Kirago, Örjan Gustafsson, Samuel Mwaniki Gaita, Sophie L. Haslett, Michael J. Gatari, Maria Elena Popa, Thomas Röckmann, Christoph Zellweger, Martin Steinbacher, Jörg Klausen, Christian Félix, David Njiru, and August Andersson
Atmos. Chem. Phys., 23, 14349–14357,Short summary
This study provides ground-observational evidence that supports earlier suggestions that savanna fires are the main emitters and modulators of carbon monoxide gas in Africa. Using isotope-based techniques, the study has shown that about two-thirds of this gas is emitted from savanna fires, while for urban areas, in this case Nairobi, primary sources approach 100 %. The latter has implications for air quality policy, suggesting primary emissions such as traffic should be targeted.
Clara M. Nussbaumer, Bryan K. Place, Qindan Zhu, Eva Y. Pfannerstill, Paul Wooldridge, Benjamin C. Schulze, Caleb Arata, Ryan Ward, Anthony Bucholtz, John H. Seinfeld, Allen H. Goldstein, and Ronald C. Cohen
Atmos. Chem. Phys., 23, 13015–13028,Short summary
NOx is a precursor to hazardous tropospheric ozone and can be emitted from various anthropogenic sources. It is important to quantify NOx emissions in urban environments to improve the local air quality, which still remains a challenge, as sources are heterogeneous in space and time. In this study, we calculate NOx emissions over Los Angeles, based on aircraft measurements in June 2021, and compare them to a local emission inventory, which we find mostly overpredicts the measured values.
Magdalena Okuljar, Olga Garmash, Miska Olin, Joni Kalliokoski, Hilkka Timonen, Jarkko V. Niemi, Pauli Paasonen, Jenni Kontkanen, Yanjun Zhang, Heidi Hellén, Heino Kuuluvainen, Minna Aurela, Hanna E. Manninen, Mikko Sipilä, Topi Rönkkö, Tuukka Petäjä, Markku Kulmala, Miikka Dal Maso, and Mikael Ehn
Atmos. Chem. Phys., 23, 12965–12983,Short summary
Highly oxygenated organic molecules (HOMs) form secondary organic aerosol that affects air quality and health. In this study, we demonstrate that in a moderately polluted city with abundant vegetation, the composition of HOMs is largely controlled by the effect of NOx on the biogenic volatile organic compound oxidation. Comparing the results from two nearby stations, we show that HOM composition and formation pathways can change considerably within small distances in urban environments.
Si-Wan Kim, Kyoung-Min Kim, Yujoo Jeong, Seunghwan Seo, Yeonsu Park, and Jeongyeon Kim
Atmos. Chem. Phys., 23, 12867–12886,Short summary
Surface ozone is a pollutant regulated for public health. This study derived surface ozone trends over South Korea from 2001 to 2021 and highlighted that South Korea has been a nonattainment area since 2010, based on the US EPA standard. However, the occurrences of high ozone condition decreased in spring during the COVID-19 pandemic, partly due to large reductions of ozone precursor concentrations in China and South Korea.
Zeyu Sun, Zheng Zong, Yang Tan, Chongguo Tian, Zeyu Liu, Fan Zhang, Rong Sun, Yingjun Chen, Jun Li, and Gan Zhang
Atmos. Chem. Phys., 23, 12851–12865,Short summary
This is the first report of ship-emitted nitrogen stable isotope composition (δ15N) of nitrogen oxides (NOx). The results showed that δ15N–NOx from ships was −18.5 ± 10.9 ‰ and increased monotonically with tightening emission regulations. The selective catalytic reduction system was the most vital factor. The temporal variation in δ15N–NOx was evaluated and can be used to select suitable δ15N–NOx for a more accurate assessment of the contribution of ship-emitted exhaust to atmospheric NOx.
Eva Y. Pfannerstill, Caleb Arata, Qindan Zhu, Benjamin C. Schulze, Roy Woods, John H. Seinfeld, Anthony Bucholtz, Ronald C. Cohen, and Allen H. Goldstein
Atmos. Chem. Phys., 23, 12753–12780,Short summary
The San Joaquin Valley is an agricultural area with poor air quality. Organic gases drive the formation of hazardous air pollutants. Agricultural emissions of these gases are not well understood and have rarely been quantified at landscape scale. By combining aircraft-based emission measurements with land cover information, we found mis- or unrepresented emission sources. Our results help in understanding of pollution sources and in improving predictions of air quality in agricultural regions.
Youwei Hong, Keran Zhang, Dan Liao, Gaojie Chen, Min Zhao, Yiling Lin, Xiaoting Ji, Ke Xu, Yu Wu, Ruilian Yu, Gongren Hu, Sung-Deuk Choi, Likun Xue, and Jinsheng Chen
Atmos. Chem. Phys., 23, 10795–10807,Short summary
Particle uptakes of HCHO and the impacts on PM2.5 and O3 production remain highly uncertain. Based on the investigation of co-occurring wintertime O3 and PM2.5 pollution in a coastal city of southeast China, we found enhanced heterogeneous formation of hydroxymethanesulfonate (HMS) and increased ROx concentrations and net O3 production rates. The findings of this study are helpful to better explore the mechanisms of key precursors for co-occurring PM2.5 and O3 pollution.
Foteini Stavropoulou, Katarina Vinković, Bert Kers, Marcel de Vries, Steven van Heuven, Piotr Korbeń, Martina Schmidt, Julia Wietzel, Pawel Jagoda, Jaroslav M. Necki, Jakub Bartyzel, Hossein Maazallahi, Malika Menoud, Carina van der Veen, Sylvia Walter, Béla Tuzson, Jonas Ravelid, Randulph Paulo Morales, Lukas Emmenegger, Dominik Brunner, Michael Steiner, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, Hugo Denier van der Gon, Antonio Delre, Maklawe Essonanawe Edjabou, Charlotte Scheutz, Marius Corbu, Sebastian Iancu, Denisa Moaca, Alin Scarlat, Alexandru Tudor, Ioana Vizireanu, Andreea Calcan, Magdalena Ardelean, Sorin Ghemulet, Alexandru Pana, Aurel Constantinescu, Lucian Cusa, Alexandru Nica, Calin Baciu, Cristian Pop, Andrei Radovici, Alexandru Mereuta, Horatiu Stefanie, Alexandru Dandocsi, Bas Hermans, Stefan Schwietzke, Daniel Zavala-Araiza, Huilin Chen, and Thomas Röckmann
Atmos. Chem. Phys., 23, 10399–10412,Short summary
In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground- and drone-based measurement techniques. We show that the total CH4 emissions in our studied areas are much higher than the emissions reported to UNFCCC, and up to three-quarters of the detected emissions are related to operational venting. Our results suggest that oil and gas production infrastructure in Romania holds a massive mitigation potential.
Chunxiang Ye, Shuzheng Guo, Weili Lin, Fangjie Tian, Jianshu Wang, Chong Zhang, Suzhen Chi, Yi Chen, Yingjie Zhang, Limin Zeng, Xin Li, Duo Bu, Jiacheng Zhou, and Weixiong Zhao
Atmos. Chem. Phys., 23, 10383–10397,Short summary
Online volatile organic compound (VOC) measurements by gas chromatography–mass spectrometry, with other O3 precursors, were used to identify key VOC and other key sources in Lhasa. Total VOCs (TVOCs), alkanes, and aromatics are half as abundant as in Beijing. Oxygenated VOCs (OVOCs) consist of 52 % of the TVOCs. Alkenes and OVOCs account for 80 % of the ozone formation potential. Aromatics dominate secondary organic aerosol potential. Positive matrix factorization decomposed residential sources.
Brandon Bottorff, Michelle M. Lew, Youngjun Woo, Pamela Rickly, Matthew D. Rollings, Benjamin Deming, Daniel C. Anderson, Ezra Wood, Hariprasad D. Alwe, Dylan B. Millet, Andrew Weinheimer, Geoff Tyndall, John Ortega, Sebastien Dusanter, Thierry Leonardis, James Flynn, Matt Erickson, Sergio Alvarez, Jean C. Rivera-Rios, Joshua D. Shutter, Frank Keutsch, Detlev Helmig, Wei Wang, Hannah M. Allen, Johnathan H. Slade, Paul B. Shepson, Steven Bertman, and Philip S. Stevens
Atmos. Chem. Phys., 23, 10287–10311,Short summary
The hydroxyl (OH), hydroperoxy (HO2), and organic peroxy (RO2) radicals play important roles in atmospheric chemistry and have significant air quality implications. Here, we compare measurements of OH, HO2, and total peroxy radicals (XO2) made in a remote forest in Michigan, USA, to predictions from a series of chemical models. Lower measured radical concentrations suggest that the models may be missing an important radical sink and overestimating the rate of ozone production in this forest.
Jenny Oh, Chubashini Shunthirasingham, Ying Duan Lei, Faqiang Zhan, Yuening Li, Abigaëlle Dalpé Castilloux, Amina Ben Chaaben, Zhe Lu, Kelsey Lee, Frank A. P. C. Gobas, Sabine Eckhardt, Nick Alexandrou, Hayley Hung, and Frank Wania
Atmos. Chem. Phys., 23, 10191–10205,Short summary
An emerging brominated flame retardant (BFR) called TBECH (1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane) has never been produced or imported for use in Canada yet is found to be one of the most abundant gaseous BFRs in the Canadian atmosphere. The recorded spatial and temporal variability of TBECH suggest that the release from imported consumer products containing TBECH is the most likely explanation for its environmental occurrence in Canada.
Olivia E. Clifton, Donna Schwede, Christian Hogrefe, Jesse O. Bash, Sam Bland, Philip Cheung, Mhairi Coyle, Lisa Emberson, Johannes Flemming, Erick Fredj, Stefano Galmarini, Laurens Ganzeveld, Orestis Gazetas, Ignacio Goded, Christopher D. Holmes, László Horváth, Vincent Huijnen, Qian Li, Paul A. Makar, Ivan Mammarella, Giovanni Manca, J. William Munger, Juan L. Pérez-Camanyo, Jonathan Pleim, Limei Ran, Roberto San Jose, Sam J. Silva, Ralf Staebler, Shihan Sun, Amos P. K. Tai, Eran Tas, Timo Vesala, Tamás Weidinger, Zhiyong Wu, and Leiming Zhang
Atmos. Chem. Phys., 23, 9911–9961,Short summary
A primary sink of air pollutants is dry deposition. Dry deposition estimates differ across the models used to simulate atmospheric chemistry. Here, we introduce an effort to examine dry deposition schemes from atmospheric chemistry models. We provide our approach’s rationale, document the schemes, and describe datasets used to drive and evaluate the schemes. We also launch the analysis of results by evaluating against observations and identifying the processes leading to model–model differences.
Qindan Zhu, Bryan Place, Eva Y. Pfannerstill, Sha Tong, Huanxin Zhang, Jun Wang, Clara M. Nussbaumer, Paul Wooldridge, Benjamin C. Schulze, Caleb Arata, Anthony Bucholtz, John H. Seinfeld, Allen H. Goldstein, and Ronald C. Cohen
Atmos. Chem. Phys., 23, 9669–9683,Short summary
Nitrogen oxide (NOx) is a hazardous air pollutant, and it is the precursor of short-lived climate forcers like tropospheric ozone and aerosol particles. While NOx emissions from transportation has been strictly regulated, soil NOx emissions are overlooked. We use the airborne flux measurements to observe NOx emissions from highways and urban and cultivated soil land cover types. We show non-negligible soil NOx emissions, which are significantly underestimated in current model simulations.
Money Ossohou, Jonathan Edward Hickman, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, Marcellin Adon, Véronique Yoboué, Eric Gardrat, Maria Dias Alvès, and Corinne Galy-Lacaux
Atmos. Chem. Phys., 23, 9473–9494,Short summary
The updated analyses of ground-based concentrations and satellite total vertical columns of atmospheric ammonia help us to better understand 21st century ammonia dynamics in sub-Saharan Africa. We conclude that the drivers of trends are agriculture in the dry savanna of Katibougou, Mali; air temperature and agriculture in the wet savanna of Djougou, Benin, and Lamto, Côte d'Ivoire; and leaf area index, air temperature, residential, and agriculture in forests of Bomassa, Republic of Congo.
Hyeri Park, Jooil Kim, Haklim Choi, Sohyeon Geum, Yeaseul Kim, Rona L. Thompson, Jens Mühle, Peter K. Salameh, Christina M. Harth, Kieran M. Stanley, Simon O'Doherty, Paul J. Fraser, Peter G. Simmonds, Paul B. Krummel, Ray F. Weiss, Ronald G. Prinn, and Sunyoung Park
Atmos. Chem. Phys., 23, 9401–9411,Short summary
Based on atmospheric HFC-23 observations, the first estimate of post-CDM HFC-23 emissions in eastern Asia for 2008–2019 shows that these emissions contribute significantly to the global emissions rise. The observation-derived emissions were much larger than the bottom-up estimates expected to approach zero after 2015 due to national abatement activities. These discrepancies could be attributed to unsuccessful factory-level HFC-23 abatement and inaccurate quantification of emission reductions.
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.
Philipp Eger, Theresa Mathes, Alex Zavarsky, and Lars Duester
Atmos. Chem. Phys., 23, 8769–8788,Short summary
We investigated the contribution of inland shipping to air pollution at the river Rhine in Germany. Land-based measurements of gaseous and particulate pollutants were carried out for more than 1 year to provide a realistic estimate for the exposure of people to air pollution close to the riverside. Emissions of nitrogen oxides and particulate matter relative to the amount of fuel used, as well as their dependence on ship size, engine type and operating conditions, were examined.
Hejun Hu, Haichao Wang, Keding Lu, Jie Wang, Zelong Zheng, Xuezhen Xu, Tianyu Zhai, Xiaorui Chen, Xiao Lu, Wenxing Fu, Xin Li, Limin Zeng, Min Hu, Yuanhang Zhang, and Shaojia Fan
Atmos. Chem. Phys., 23, 8211–8223,Short summary
Nitrate radical chemistry is critical to the degradation of volatile organic compounds (VOCs) and secondary organic aerosol formation. This work investigated the level, seasonal variation, and trend of nitrate radical reactivity towards volatile organic compounds (kNO3) in Beijing. We show the key role of isoprene and styrene in regulating seasonal variation in kNO3 and rebuild a long-term record of kNO3 based on the reported VOC measurements.
Jie Wang, Haichao Wang, Yee Jun Tham, Lili Ming, Zelong Zheng, Guizhen Fang, Cuizhi Sun, Zhenhao Ling, Jun Zhao, and Shaojia Fan
Many works reported NO3 chemistry in inland regions, while less targeted marine regions. We measured N2O5 and related species on a typical island and found intensive nighttime chemistry and rapid NO3 loss. NO contributed significantly to NO3 loss despite the sub-ppbv level, suggesting nocturnal NO3 reactions would be largely enhanced once without NO emission in the open ocean. This highlights the strong influences of urban outflow on downward marine areas in terms of nighttime chemistry.
Eliane Gomes Alves, Raoni Aquino Santana, Cléo Quaresma Dias-Júnior, Santiago Botía, Tyeen Taylor, Ana Maria Yáñez-Serrano, Jürgen Kesselmeier, Efstratios Bourtsoukidis, Jonathan Williams, Pedro Ivo Lembo Silveira de Assis, Giordane Martins, Rodrigo de Souza, Sérgio Duvoisin Júnior, Alex Guenther, Dasa Gu, Anywhere Tsokankunku, Matthias Sörgel, Bruce Nelson, Davieliton Pinto, Shujiro Komiya, Diogo Martins Rosa, Bettina Weber, Cybelli Barbosa, Michelle Robin, Kenneth J. Feeley, Alvaro Duque, Viviana Londoño Lemos, Maria Paula Contreras, Alvaro Idarraga, Norberto López, Chad Husby, Brett Jestrow, and Iván Mauricio Cely Toro
Atmos. Chem. Phys., 23, 8149–8168,Short summary
Isoprene is emitted mainly by plants and can influence atmospheric chemistry and air quality. But, there are uncertainties in model emission estimates and follow-up atmospheric processes. In our study, with long-term observational datasets of isoprene and biological and environmental factors from central Amazonia, we show that isoprene emission estimates could be improved when biological processes were mechanistically incorporated into the model.
Thais Luarte, Victoria A. Gómez-Aburto, Ignacio Poblete-Castro, Eduardo Castro-Nallar, Nicolas Huneeus, Marco Molina-Montenegro, Claudia Egas, Germán Azcune, Andrés Pérez-Parada, Rainier Lohmann, Pernilla Bohlin-Nizzetto, Jordi Dachs, Susan Bengtson-Nash, Gustavo Chiang, Karla Pozo, and Cristóbal J. Galbán-Malagón
Atmos. Chem. Phys., 23, 8103–8118,Short summary
In the last 40 years, different research groups have reported on the atmospheric concentrations of persistent organic pollutants in Antarctica. In the present work, we make a compilation to understand the historical trends and estimate the atmospheric half-life of each compound. Of the compounds studied, HCB was the only one that showed no clear trend, while the rest of the studied compounds showed a significant decrease over time. This is consistent with results for polar and sub-polar zones.
Midhun George, Maria Dolores Andrés Hernández, Vladyslav Nenakhov, Yangzhuoran Liu, John Philip Burrows, Birger Bohn, Eric Förster, Florian Obersteiner, Andreas Zahn, Theresa Harlaß, Helmut Ziereis, Hans Schlager, Benjamin Schreiner, Flora Kluge, Katja Bigge, and Klaus Pfeilsticker
Atmos. Chem. Phys., 23, 7799–7822,Short summary
The applicability of photostationary steady-state (PSS) assumptions to estimate the amount of the sum of peroxy radicals (RO2*) during the EMeRGe airborne observations from the known radical chemistry and onboard measurements of RO2* precursors, photolysis frequencies, and other trace gases such as NOx and O3 was investigated. The comparison of the calculated RO2* with the actual measurements provides an insight into the main processes controlling their concentration in the air masses measured.
Ross Petersen, Thomas Holst, Meelis Mölder, Natascha Kljun, and Janne Rinne
Atmos. Chem. Phys., 23, 7839–7858,Short summary
We investigate variability in the vertical distribution of volatile organic compounds (VOCs) in boreal forest, determined through multiyear measurements at several heights in a boreal forest in Sweden. VOC source/sink seasonality in canopy was explored using these vertical profiles and with measurements from a collection of sonic anemometers on the station flux tower. Our results show seasonality in the source/sink distribution for several VOCs, such as monoterpenes and water-soluble compounds.
Wanyun Xu, Yuxuan Bian, Weili Lin, Yingjie Zhang, Yaru Wang, Zhiqiang Ma, Xiaoyi Zhang, Gen Zhang, Chunxiang Ye, and Xiaobin Xu
Atmos. Chem. Phys., 23, 7635–7652,Short summary
Tropospheric ozone (O3) and peroxyacetyl nitrate (PAN) are both photochemical pollutants harmful to the ecological environment and human health, especially in the Tibetan Plateau (TP). However, the factors determining their variations in the TP have not been comprehensively investigated. Results from field measurements and observation-based models revealed that day-to-day variations in O3 and PAN were in fact controlled by distinct physiochemical processes.
Megan E. McCabe, Ilana B. Pollack, Emily V. Fischer, Kathryn M. Steinmann, and Dana R. Caulton
Atmos. Chem. Phys., 23, 7479–7494,Short summary
Agriculture emissions, including those from beef and dairy cattle feeding operations, make up a large portion of the United States’ total greenhouse gas emissions, but many of these operations reside in areas where methane from oil and natural gas is prevalent, making it difficult to attribute methane in these areas. This work investigates two approaches to emission attribution for cattle feeding operations and provides guidance for emission attribution in other complicated regions.
Yifei Song, Chaoyang Xue, Yuanyuan Zhang, Pengfei Liu, Fengxia Bao, Xuran Li, and Yujing Mu
We present measurements of HONO flux and related parameters over an agricultural field during a whole growing season of summer Maize. This dataset allows studies on the characteristics and influencing factors of soil HONO emissions, determination of HONO emission factors, estimation of total HONO emissions at a national scale, and the discussion on future environmental policies, in terms of mitigating regional air pollution.
Can Ye, Keding Lu, Xuefei Ma, Wanyi Qiu, Shule Li, Xinping Yang, Chaoyang Xue, Tianyu Zhai, Yuhan Liu, Xuan Li, Yang Li, Haichao Wang, Zhaofeng Tan, Xiaorui Chen, Huabin Dong, Limin Zeng, Min Hu, and Yuanhang Zhang
In this study, combing comprehensive field measurements and a box model, we found NO2 conversion on the ground surface was the most important source for HONO production among the proposed heterogeneous and gas-phase HONO sources. In addition, HONO was found to evidently enhance O3 production and aggravate O3 pollution in summer in China. Our study improved our understanding of the relative importance of different HONO sources and the crucial role of HONO in O3 formation in polluted areas.
Georgios I. Gkatzelis, Matthew M. Coggon, Chelsea E. Stockwell, Rebecca S. Hornbrook, Hannah Allen, Eric C. Apel, Katherine Ball, Megan M. Bela, Donald R. Blake, Ilann Bourgeois, Steven S. Brown, Pedro Campuzano-Jost, Jason M. St. Clair, James H. Crawford, John D. Crounse, Douglas A. Day, Joshua DiGangi, Glenn Diskin, Alan Fried, Jessica Gilman, Hongyu Guo, Johnathan W. Hair, Hannah A. Halliday, Thomas F. Hanisco, Reem Hannun, Alan Hills, Gregory Huey, Jose L. Jimenez, Joseph M. Katich, Aaron Lamplugh, Young Ro Lee, Jin Liao, Jakob Lindaas, Stuart A. McKeen, Tomas Mikoviny, Benjamin A. Nault, James A. Neuman, John B. Nowak, Demetrios Pagonis, Jeff Peischl, Anne E. Perring, Felix Piel, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Thomas B. Ryerson, Melinda K. Schueneman, Rebecca H. Schwantes, Joshua P. Schwarz, Kanako Sekimoto, Vanessa Selimovic, Taylor Shingler, David J. Tanner, Laura Tomsche, Krystal Vasquez, Patrick R. Veres, Rebecca Washenfelder, Petter Weibring, Paul O. Wennberg, Armin Wisthaler, Glenn Wolfe, Caroline Womack, Lu Xu, Robert Yokelson, and Carsten Warneke
This study reports emissions of gases and particles from wildfires. These emissions are related to chemical proxies that can be measured by satellite and incorporated into models to improve predictions of wildfire impacts on air quality and climate.
Nathaniel Brockway, Peter Peterson, Katja Bigge, Kristian Hajny, Paul Shepson, Kerri Pratt, Jose Fuentes, Tim Starn, Robert Kaeser, Brian Stirm, and William Simpson
Bromine monoxide (BrO) strongly affects atmospheric chemistry in the springtime Arctic, yet there are still many uncertainties around its sources and recycling, particularly in the context of a rapidly changing Arctic. In this study, we observed BrO as a function of altitude above the Alaskan Arctic. We found that BrO was often most concentrated near the ground, confirming the ability of snow to produce and recycle reactive bromine and identified four common vertical distributions of BrO.
Haeyoung Lee, Wonick Seo, Shanlan Li, Soojeong Lee, Samuel Takele Kenea, and Sangwon Joo
Atmos. Chem. Phys., 23, 7141–7159,Short summary
We introduced three Korea Meteorological Administration (KMA) monitoring stations with monitoring systems and measurement uncertainty. We also analyzed the regional characteristics of CH4 at each KMA station. CH4 levels measured at KMA stations are compared to those measured at other Asian stations. From the long-term records of CH4 and δ13CH4 at AMY, we confirmed that the source of CH4xs changed from the past (2006 to 2010) to recent (2016 to 2020) years in East Asia.
Robert G. Ryan, Eloise A. Marais, Eleanor Gershenson-Smith, Robbie Ramsay, Jan-Peter Muller, Jan-Lukas Tirpitz, and Udo Frieß
Atmos. Chem. Phys., 23, 7121–7139,Short summary
We describe the first data retrieval from a newly installed instrument providing measurements of vertical profiles of air pollution over Central London during heatwaves in summer 2022. We use these observations with surface air quality network measurements to support interpretation that an exponential increase in biogenic emissions of isoprene during heatwaves provides the limiting ingredient for severe ozone pollution, leading to non-compliance with the national ozone air quality standard.
Jérémy Gueffier, François Gheusi, Marie Lothon, Véronique Pont, Alban Philibert, Fabienne Lohou, Solène Derrien, Yannick Bezombes, Gilles Athier, Yves Meyerfeld, and Antoine Vial
This study investigates the link between weather regimes and atmospheric composition at a Pyrenean observatory. Five years of meteorological data were synchronized on a daily basis, then, using a clustering method, separated into 6 groups of observation days, most of them showing marked characteristics of different weather regimes (fair and disturbed weather, winter windstorms, foehn). Statistical differences in gas and particle concentrations appeared between the groups, and were discussed.
Zhouxing Zou, Qianjie Chen, Men Xia, Qi Yuan, Yi Chen, Yanan Wang, Enyu Xiong, Zhe Wang, and Tao Wang
Atmos. Chem. Phys., 23, 7057–7074,Short summary
We present OH observation and model simulation results at a coastal site in Hong Kong. The model predicted the OH concentration under high-NOx well but overpredicted it under low-NOx conditions. This implies an insufficient understanding of OH chemistry under low-NOx conditions. We show evidence of missing OH sinks as a possible cause of the overprediction.
Alina Fiehn, Maximilian Eckl, Julian Kostinek, Michał Gałkowski, Christoph Gerbig, Michael Rothe, Thomas Röckmann, Malika Menoud, Hossein Maazallahi, Martina Schmidt, Piotr Korbeń, Jarosław Neçki, Mila Stanisavljević, Justyna Swolkień, Andreas Fix, and Anke Roiger
During the CoMet mission in the Upper Silesian Coal Basin (USCB) ground-based and airborne air samples were taken, and analyzed for the isotopic composition of CH4 to derive the mean signature of the USCB and the source signatures of individual coal mines. Using δ2H signatures, the biogenic emissions from the USCB account for 15–50 % of total emissions, which is underestimated in common emission inventories. This demonstrates the importance of δ2H-CH4 observations for methane source attribution.
Yaqin Gao, Hongli Wang, Lingling Yuan, Shengao Jing, Bin Yuan, Guofeng Shen, Liang Zhu, Abigail Koss, Yingjie Li, Qian Wang, Dan Dan Huang, Shuhui Zhu, Shikang Tao, Shengrong Lou, and Cheng Huang
Atmos. Chem. Phys., 23, 6633–6646,Short summary
A near-complete speciation of reactive organic gases from residential combustion was developed to get more insights into their atmospheric effects. Oxygenated species, higher hydrocarbons and nitrogen-containing species played larger roles in these emissions compared with common hydrocarbons. Based on the near-complete speciation, these emissions were largely underestimated, leading to more underestimation of their hydroxyl radical reactivity and secondary organic aerosol formation potential.
Katrin Müller, Jordis S. Tradowsky, Peter von der Gathen, Christoph Ritter, Sharon Patris, Justus Notholt, and Markus Rex
The Palau Atmospheric Observatory is introduced as an ideal site to detect changes in atmospheric composition and dynamics above the remote Tropical West Pacific. We focus on the ozone sounding program from 2016–2021, including El Nino 2016. The year-round high convective activity is reflected in dominant low tropospheric ozone and high relative humidity. The seasonal distribution of both constituents is unique compared to other tropical sites and modulated by the Intertropical Convergence Zone.
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,Short summary
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.
Chengzhi Xing, Shiqi Xu, Yuhang Song, Cheng Liu, Yuhan Liu, Keding Lu, Wei Tan, Chengxin Zhang, Qihou Hu, Shanshan Wang, Hongyu Wu, and Hua Lin
Atmos. Chem. Phys., 23, 5815–5834,Short summary
High RH could contribute to the secondary formation of HONO in the sea atmosphere. High temperature could promote the formation of HONO from NO2 heterogeneous reactions in the sea and coastal atmosphere. The aerosol surface plays a more important role during the above process in coastal and sea cases. The generation rate of HONO from the NO2 heterogeneous reaction in the sea cases is larger than that in inland cases in higher atmospheric layers above 600 m.
Daniel John Katz, Aroob Abdelhamid, Harald Stark, Manjula R. Canagaratna, Douglas R. Worsnop, and Eleanor C. Browne
Atmos. Chem. Phys., 23, 5567–5585,Short summary
Ambient ion chemical composition measurements provide insight into trace gases that are precursors for the formation and growth of new aerosol particles. We use a new data analysis approach to increase the chemical information from these measurements. We analyze results from an agricultural region, a little studied land use type that is ~41 % of global land use, and find that the composition of gases important for aerosol formation and growth differs significantly from that in other ecosystems.
Amelia M. H. Bond, Markus M. Frey, Jan Kaiser, Jörg Kleffmann, Anna E. Jones, and Freya A. Squires
Atmos. Chem. Phys., 23, 5533–5550,Short summary
Atmospheric nitrous acid (HONO) amount fractions measured at Halley Research Station, Antarctica, were found to be low. Vertical fluxes of HONO from the snow were also measured and agree with the estimated HONO production rate from photolysis of snow nitrate. In a simple box model of HONO sources and sinks, there was good agreement between the measured flux and amount fraction. HONO was found to be an important OH radical source at Halley.
Rujing Yin, Xiaoxiao Li, Chao Yan, Runlong Cai, Ying Zhou, Juha Kangasluoma, Nina Sarnela, Janne Lampilahti, Tuukka Petäjä, Veli-Matti Kerminen, Federico Bianchi, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 23, 5279–5296,Short summary
Atmospheric cluster ions are important constituents in the atmosphere. However, the quantitative research on their compositions is still limited, especially in urban environments. Here we demonstrate the feasibility of an in situ quantification method of cluster ions measured by a high-resolution mass spectrometer and reveal their governing factors, sources, and sinks in urban Beijing through quantitative analysis of cluster ions, reagent ions, neutral molecules, and condensation sink.
Qiaozhi Zha, Wei Huang, Diego Aliaga, Otso Peräkylä, Liine Heikkinen, Alkuin Maximilian Koenig, Cheng Wu, Joonas Enroth, Yvette Gramlich, Jing Cai, Samara Carbone, Armin Hansel, Tuukka Petäjä, Markku Kulmala, Douglas Worsnop, Victoria Sinclair, Radovan Krejci, Marcos Andrade, Claudia Mohr, and Federico Bianchi
Atmos. Chem. Phys., 23, 4559–4576,Short summary
We investigate the chemical composition of atmospheric cluster ions from January to May 2018 at the high-altitude research station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes. With state-of-the-art mass spectrometers and air mass history analysis, the measured cluster ions exhibited distinct diurnal and seasonal patterns, some of which contributed to new particle formation. Our study will improve the understanding of atmospheric ions and their role in high-altitude new particle formation.
Michael P. Vermeuel, Gordon A. Novak, Delaney B. Kilgour, Megan S. Claflin, Brian M. Lerner, Amy M. Trowbridge, Jonathan Thom, Patricia A. Cleary, Ankur R. Desai, and Timothy H. Bertram
Atmos. Chem. Phys., 23, 4123–4148,Short summary
Reactive carbon species emitted from natural sources such as forests play an important role in the chemistry of the atmosphere. Predictions of these emissions are based on plant responses during the growing season and do not consider potential effects from seasonal changes. To address this, we made measurements of reactive carbon over a forest during the summer to autumn transition. We learned that observed concentrations and emissions for some key species are larger than model predictions.
Huiming Lin, Yindong Tong, Long Chen, Chenghao Yu, Zhaohan Chu, Qianru Zhang, Xiufeng Yin, Qianggong Zhang, Shichang Kang, Junfeng Liu, James Schauer, Benjamin de Foy, and Xuejun Wang
Atmos. Chem. Phys., 23, 3937–3953,Short summary
Lhasa is the largest city in the Tibetan Plateau, and its atmospheric mercury concentrations represent the highest level of pollution in this region. Unexpectedly high concentrations of atmospheric mercury species were found. Combined with the trajectory analysis, the high atmospheric mercury concentrations may have originated from external long-range transport. Local sources, especially special mercury-related sources, are important factors influencing the variability of atmospheric mercury.
Andersson, E., Bauer, P., Beljaars, A., Chevallier, F., Hólm, E., Janisková, M., Kallberg, P., Kelly, G., Lopez, P., McNally, A., Moreau, E., Simmons, A. J., Thépaut, J.-N., and Tompkins, A. M.: Assimilation and modeling of the atmospheric hydrological cycle in the ECMWF forecasting system, Bull. Amer. Meteor. Soc., 86, 387–402. https://doi.org/10.1175/BAMS-86-3-387, 2005.
Bechtold, P., Köhler, M., Jung, T., Doblas-Reyes, F., Leutbecher, M., Rodwell, M. J., Vitart, F., and Balsamo, G.: Advances in simulating atmospheric variability with the ECMWF model: from synoptic to decadal timescales, Q. J. R. Meteorol. Soc., 134, 1337–1351, 2008.
Blom, C. E., Cortesi, U., and Redaelli, G., ENVISAT validation: Introduction to the correlative measurements by the chemistry payload on board the M-55 Geophysica, Proc. of the 16th ESA Symposium on European Rocket and Balloon Programmes and Related Research, St. Gallen, Switzerland, 2–5 June 2003 (ESA SP-530, August 2003).
Cairo, F., Pommereau, J. P., Law, K. S., Schlager, H., Garnier, A., Fierli, F., Ern, M., Streibel, M., Arabas, S., Borrmann, S., Berthelier, J. J., Blom, C., Christensen, T., D'Amato, F., Di Donfrancesco, G., Deshler, T., Diedhiou, A., Durry, G., Engelsen, O., Goutail, F., Harris, N. R. P., Kerstel, E. R. T., Khaykin, S., Konopka, P., Kylling, A., Larsen, N., Lebel, T., Liu, X., MacKenzie, A. R., Nielsen, J., Oulanowski, A., Parker, D. J., Pelon, J., Polcher, J., Pyle, J. A., Ravegnani, F., Rivière, E. D., Robinson, A. D., Röckmann, T., Schiller, C., Simões, F., Stefanutti, L., Stroh, F., Some, L., Siegmund, P., Sitnikov, N., Vernier, J. P., Volk, C. M., Voigt, C., von Hobe, M., Viciani, S., and Yushkov, V.: An introduction to the SCOUT-AMMA stratospheric aircraft, balloons and sondes campaign in West Africa, August 2006: rationale and roadmap, Atmos. Chem. Phys., 10, 2237–2256, https://doi.org/10.5194/acp-10-2237-2010, 2010.
Castanheira, J. M., Peevey, T. R., Marques, C. A. F., and Olsen, M. A.: Relationships between Brewer-Dobson circulation, double tropopauses, ozone and stratospheric water vapour, Atmos. Chem. Phys., 12, 10195–10208, https://doi.org/10.5194/acp-12-10195-2012, 2012.
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P., Kobayashi, S., Andrea, U., Balmaseda, M. A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A. C. M., von de Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S. B., Hersbach, H., Hólm, E. V., Isaksen, L., Kallberg, P., Köhler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M., Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thépaut, J.-N., and Vitart, F.: The ERA-Interim reanalysis: configuration and performance of the data assimilation system, Q. J. R. Meteorol. Soc., 137, 553–597, https://doi.org/10.1002/qj.828 2011.
Dyroff, C., Zahn, A., Christner, E., Forbes, R. M., Tompkins, A. M., and van Velthoven, P. F. J.: Comparison of ECMWF analysis and forecast humidity data to CARIBIC upper troposphere and lower stratosphere observations, Q. J. R. Meteorol. Soc., https://doi.org/10.1002/qj.2400, online first, 2014.
Engel, A., Bönisch, H., Brunner, D., Fischer, H., Franke, H., Günther, G., Gurk, C., Hegglin, M., Hoor, P., Königstedt, R., Krebsbach, M., Maser, R., Parchatka, U., Peter, T., Schell, D., Schiller, C., Schmidt, U., Spelten, N., Szabo, T., Weers, U., Wernli, H., Wetter, T., and Wirth, V.: Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview, Atmos. Chem. Phys., 6, 283–301, https://doi.org/10.5194/acp-6-283-2006, 2006.
Flentje, H., Dörnbrack, A., Fix, A., Ehret, G., and Hólm, E.: Evaluation of ECMWF water vapour fields by airborne differential absorption lidar measurements: a case study between Brazil and Europe, Atmos. Chem. Phys., 7, 5033–5042, https://doi.org/10.5194/acp-7-5033-2007, 2007.
Forbes, R., Tompkins, A. M., and Untch, A.: A new prognostic bulk microphysics scheme for the IFS, ECMWF Technical Memoranda No. 649, available at:http://www.ecmwf.int/ (last access: 13 October 2014), 2011.
Forster, P. M. de F. and Shine, K. P.: Radiative forcing and temperature trends from stratospheric ozone changes, J. Geophys. Res., 102, 10841–10855, 1997.
Fueglistaler, S., Dessler, A. E., Dunkerton, T. J., Folkins, I., Fu, Q. and Mote, P. W.: Tropical tropopause layer, Rev. Geophys., 47, RG1004, https://doi.org/10.1029/2008RG000267, 2009.
Haynes, P. and Shuckburgh, E.: Effective diffusivity as a diagnostic of atmospheric transport 2. Troposphere and lower stratosphere, J. Geophys. Res., 105, 22795–22810, 2000.
Hólm, E.: Revision of the ECMWF humidity analysis: Construction of a Gaussian control variable, Proceedings of the ECMWF/GEWEX Workshop on Humidity Analysis, 8–11 July 2002, ECMWF Reading, UK, 2002.
Jensen, E. and Pfister, L.: Transport and freeze-drying in the tropical tropopause layer, J. Geophys. Res., 109, D02207, https://doi.org/10.1029/2003JD004022, 2004.
Jones, R. L., and Pyle, J. A.: Observations of CH4 and N2O by the NIMBUS 7 SAMS: A comparison with in situ data and two-dimensional numerical model calculations, J. Geophys. Res., 89, 3D1644, https://doi.org/10.1029/JD089iD04p05263, 1984.
Krämer, M., Schiller, C., Afchine, A., Bauer, R., Gensch, I., Mangold, A., Schlicht, S., Spelten, N., Sitnikov, N., Borrmann, S., de Reus, M., and Spichtinger, P.: Ice supersaturations and cirrus cloud crystal numbers, Atmos. Chem. Phys., 9, 3505–3522, https://doi.org/10.5194/acp-9-3505-2009, 2009.
Kunz, A., Schiller, C., Rohrer, F., Smit, H. G. J., Nedelec, P., and Spelten, N.: Statistical analysis of water vapour and ozone in the UT/LS observed during SPURT and MOZAIC, Atmos. Chem. Phys., 8, 6603–6615, https://doi.org/10.5194/acp-8-6603-2008, 2008.
Kunz, A., Konopka, P., Müller, R., and Pan, L. L.: Dynamical tropopause based on isentropic potential vorticity gradients, J. Geophys. Res., 116, D01110, https://doi.org/10.1029/2010JD014343, 2011a.
Kunz, A., Pan, L. L., Konopka, P., Kinnison, D. E., and Tilmes, S.: Chemical and dynamical discontinuity at the extra-tropical tropopause-based on START08 and WACCM analyses, J. Geophys. Res., 116, D24302, https://doi.org/10.1029/2011JD016686, 2011b.
Kunz, A., Müller, R., Homonnai, V., Jánosi, I. M., Hurst, D., Rap, A., Forster, P. M., Rohrer, F., Spelten, N., and Riese, M.: Extending water vapor trend observations over Boulder into the tropopause region: trend uncertainties and resulting radiative forcing, J. Geophys. Res., 118, 11269–11284, https://doi.org/10.1002/jgrd.50831, 2013.
Lamquin, N., Gierens, K., Stubenrauch, C. J., and Chatterjee, R.: Evaluation of upper tropospheric humidity forecasts from ECMWF using AIRS and CALIPSO data, Atmos. Chem. Phys., 9, 1779–1793, https://doi.org/10.5194/acp-9-1779-2009, 2009.
Luebke, A. E., Avallone, L. M., Schiller, C., Meyer, J., Rolf, C., and Krämer, M.: Ice water content of Arctic, midlatitude, and tropical cirrus – Part 2: Extension of the database and new statistical analysis, Atmos. Chem. Phys., 13, 6447–6459, https://doi.org/10.5194/acp-13-6447-2013, 2013.
Luo, Z., Kley, D., Johnson, R. H., and Smit, H.: Ten Years of Measurements of Tropical Upper-Tropospheric Water Vapor by MOZAIC. Part II: Assessing the ECMWF Humidity Analysis, J. Climate, 21, 1449–1466, https://doi.org/10.1175/2007JCLI1887.1, 2007.
McKenna, D., S., Konopka, P., Grooß, J., U., Günther, G., and R. Müller: A new Chemical Lagrangian Model of the Stratosphere (CLaMS), 1. Formulation of advection and mixing, J. Geophys. Res., 107, 4309, https://doi.org/10.1029/2000JD000114, 2002.
Oikonomou, E. K., and O'Neill, A.: Evaluation of ozone and water vapor fields from the ECMWF reanalysis ERA-40 during 1991–1999 in comparison with UARS satellite and MOZAIC aircraft observations, J. Geophys. Res., 111, D14109, https://doi.org/10.1029/2004JD005341, 2006.
Olsen, M. A., Douglas, A. R., Schoeberl, M. R., Rodriguez, J. M., and Yoshida, Y.: Interannual variability of ozone in the winter lower stratosphere and the relationship to lamina and irreversible transport, J. Geophys. Res., 115, D15305, https://doi.org/10.1029/2009JD013004, 2010.
Pan, L. L., Randel, W. J., Gary, B. L., Mahoney, M. J., and Hintsa, E. J.: Definition and sharpness of the extratropical tropopause: A trace gas perspective, J. Geophys. Res., 109, D23103, https://doi.org/10.1029/2004JD004982, 2004.
Pan, L. L., Kunz, A., Homeyer, C. R., Munchak, L. A., Kinnison, D. E., and Tilmes, S.: Commentary on using equivalent latitude in the upper troposphere and lower stratosphere, Atmos. Chem. Phys., 12, 9187–9199, https://doi.org/10.5194/acp-12-9187-2012, 2012.
Ploeger, F., Günther, G., Konopka, P., Fueglistaler, S., Müller, R., Hoppe, C., Kunz, A., Spang, R., Grooß, J.-U., and Riese, M.: Horizontal water vapor transport in the lower stratosphere from subtropics to high latitudes during boreal summer, J. Geophys. Res., 118, 1–17, https://doi.org/10.1002/jgrd.50636, 2013.
Ravishankara, A. R.: Water vapor in the lower stratosphere, Science, 337, 809–810, 2012.
Riese, M., Ploeger, F., Rap, A., Vogel, B., Konopka, P., Dameris, M., and Forster, P.: Impact of uncertainties in atmospheric mixing on simulated UTLS composition and related radiative effects, J. Geophys. Res., 117, D16305, https://doi.org/10.1029/2012JD017751, 2012.
Röckmann, T., Grooß, J.-U., and Müller, R.: The impact of anthropogenic chlorine emissions, stratospheric ozone change and chemical feedbacks on stratospheric water, Atmos. Chem. Phys., 4, 693–699, https://doi.org/10.5194/acp-4-693-2004, 2004.
Rohrer, F. and Berresheim, H.: Strong correlation between levels of tropospheric hydroxyl radicals and solar ultraviolet radiation, Nature, 442, 184–187, 2006.
Rohs, S., Schiller, C., Riese, M., Engel, A., Schmidt, U., Wetter, T., Levin, I., Nakazawa, T., and Aoki, S.: Long-term changes of methane and hydrogen in the stratosphere in the period 1978–2003 and their impact on the abundance of stratospheric water vapor, J. Geophys. Res., 111, D14315, https://doi.org/10.1029/2005JD006877, 2006.
Schiller, C., Krämer, M., Afchine, A., Spelten, N., and Sitnikov, N.: The ice water content of Arctic, midlatitude and tropical cirrus, J. Geophys. Res., 113, D24208, https://doi.org/10.1029/2008JD010342, 2008.
Schiller, C., Grooß, J.-U., Konopka, P., Plöger, F., Silva dos Santos, F. H., and Spelten, N.: Hydration and dehydration at the tropical tropopause, Atmos. Chem. Phys., 9, 9647–9660, https://doi.org/10.5194/acp-9-9647-2009, 2009.
Schäfler, A., Dörnbrack, A., Kiemle, C., Rahm, S., and Wirth, M.: Tropospheric water vapor transport as determined from airborne lidar measurements, J. Atmos. Ocean. Techn., 27, 2017–2030, https://doi.org/10.1175/2010JTECHA1418.1, 2010.
Solomon, S., Rosenlof, K. H., Portman, R. W., Daniel, J. S., Davis, S. M., Sanford, F. J., and Plattner, G.-K.: Contributions of stratospheric water vapor to decadal changes in the rate of global warming, Science, 327, 1219–1223, 2010.
Stenke, A., Grewe, V., and Ponater, M.: Lagrangian transport of water vapor and cloud water in the ECHAM4 GCM and its impact on the cold bias, Clim. Dyn., 31, 491–506, 2008.
Tilmes, S., Pan, L. L., Hoor, P., Atlas, E., Avery, M. A., Campos, T., Christensen, L. E., Diskin, G. S., Gao, R.-S., Herman, R. L., Hintsa, E. J., Loewenstein, M., Lopez, J., Paige, M. E., Pittman, J. V., Podolske, J. R., Proffitt, M. R., Sachse, G. W., Schiller, C., Schlager, H., Smith, J., Spelten, N., Webster, C., Weinheimer, A., and Zondlo, M. A.: An aircraft-based upper troposphere lower stratosphere O3, CO, and H2O climatology for the Northern Hemisphere, J. Geophys. Res., 115, D14303, https://doi.org/10.1029/2009JD012731, 2010.
Tompkins, A. M., Gierens, K., and Rädel, G.: Ice supersaturation in the ECMWF integrated forecast system, Q. J. R. Meteorol. Soc., 133, 53–63, https://doi.org/10.1002/qj.14, 2007.
Uppala, S. M., Kållberg, P. W., Simmons, A. J., Andrae, U., Bechtold, V. D. C., Fiorino, M., Gibson, J. K., Haseler, J., Hernandez, A., Kelly, G. A., Li, X., Onogi, K., Saarinen, S., Sokka, N., Allan, R. P., Andersson, E., Arpe, K., Balmaseda, M. A., Beljaars, A. C. M., Berg, L. V. D., Bidlot, J., Bormann, N., Caires, S., Chevallier, F., Dethof, A., Dragosavac, M., Fisher, M., Fuentes, M., Hagemann, S., Hólm, E., Hoskins, B. J., Isaksen, L., Janssen, P. A. E. M., Jenne, R., Mcnally, A. P., Mahfouf, J.-F., Morcrette, J.-J., Rayner, N. A., Saunders, R. W., Simon, P., Sterl, A., Trenberth, K. E., Untch, A., Vasiljevic, D., Viterbo, P. and Woollen, J. : The ERA-40 reanalysis, Q. J. R. Meteorol. Soc., 131, 2961–3012, https://doi.org/10.1256/qj.04.176, 2006.
Vaughan, G., Schiller, C., MacKenzie, A. R., Bower, K., Peter, T., Schlager, H., Harris, N. R. P., and May, P. T. E.: SCOUT-O3/ACTIVE High-altitude aircraft measurements around deep tropical convection, B. Am. Meteorol. Soc., 89, 647–662, 10.1175/BAMS-89-5-647, 2008.
von Hobe, M., Bekki, S., Borrmann, S., Cairo, F., D'Amato, F., Di Donfrancesco, G., Dörnbrack, A., Ebersoldt, A., Ebert, M., Emde, C., Engel, I., Ern, M., Frey, W., Genco, S., Griessbach, S., Grooß, J.-U., Gulde, T., Günther, G., Hösen, E., Hoffmann, L., Homonnai, V., Hoyle, C. R., Isaksen, I. S. A., Jackson, D. R., Jánosi, I. M., Jones, R. L., Kandler, K., Kalicinsky, C., Keil, A., Khaykin, S. M., Khosrawi, F., Kivi, R., Kuttippurath, J., Laube, J. C., Lefèvre, F., Lehmann, R., Ludmann, S., Luo, B. P., Marchand, M., Meyer, J., Mitev, V., Molleker, S., Müller, R., Oelhaf, H., Olschewski, F., Orsolini, Y., Peter, T., Pfeilsticker, K., Piesch, C., Pitts, M. C., Poole, L. R., Pope, F. D., Ravegnani, F., Rex, M., Riese, M., Röckmann, T., Rognerud, B., Roiger, A., Rolf, C., Santee, M. L., Scheibe, M., Schiller, C., Schlager, H., Siciliani de Cumis, M., Sitnikov, N., Søvde, O. A., Spang, R., Spelten, N., Stordal, F., Sumin'ska-Ebersoldt, O., Ulanovski, A., Ungermann, J., Viciani, S., Volk, C. M., vom Scheidt, M., von der Gathen, P., Walker, K., Wegner, T., Weigel, R., Weinbruch, S., Wetzel, G., Wienhold, F. G., Wohltmann, I., Woiwode, W., Young, I. A. K., Yushkov, V., Zobrist, B., and Stroh, F.: Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions (RECONCILE): activities and results, Atmos. Chem. Phys., 13, 9233–9268, https://doi.org/10.5194/acp-13-9233-2013, 2013.
Zöger, M., Afchine, A., Eicke, N., Gerhards, M.-T., Klein, E., McKenna, D. S., Mörschel, U., Schmidt, U., Tan, V., Tuitjer, F., Woyke, T., and Schiller, C.: Fast in-situ stratospheric hygrometers: A new family of balloon-borne and airborne Lyman α photofragment fluorescence hygrometers, J. Geophys. Res., 104, 1807–1816, 1999.