Articles | Volume 20, issue 21
https://doi.org/10.5194/acp-20-12483-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-20-12483-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
31 Oct 2020
Research article |
| 31 Oct 2020
| 31 Oct 2020
Polar stratospheric clouds initiated by mountain waves in a global chemistry–climate model: a missing piece in fully modelling polar stratospheric ozone depletion
Andrew Orr
CORRESPONDING AUTHOR
British Antarctic Survey, Cambridge, UK
J. Scott Hosking
British Antarctic Survey, Cambridge, UK
Aymeric Delon
Ecole normale supérieure Paris-Saclay, Paris, France
Lars Hoffmann
Forschungszentrum Jülich, Jülich Supercomputing Centre,
Jülich, Germany
Reinhold Spang
Forschungszentrum Jülich, Institut für Energie und
Klimaforschung, Stratosphäre, IEK-7, Jülich, Germany
Tracy Moffat-Griffin
British Antarctic Survey, Cambridge, UK
James Keeble
National Centre for Atmospheric Science (NCAS), University of
Cambridge, Cambridge, UK
Department of Chemistry, University of Cambridge, Cambridge, UK
Nathan Luke Abraham
National Centre for Atmospheric Science (NCAS), University of
Cambridge, Cambridge, UK
Department of Chemistry, University of Cambridge, Cambridge, UK
Peter Braesicke
Karlsruher Institut für Technologie, Institut für Meteorologie und Klimaforschung, Karlsruhe, Germany
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Abhiraj Bishnoi, Olaf Stein, Catrin I. Meyer, René Redler, Norbert Eicker, Helmuth Haak, Lars Hoffmann, Daniel Klocke, Luis Kornblueh, and Estela Suarez
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Bärbel Vogel, C. 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
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Dimethyl sulfide (DMS) is an important trace gas emitted from the ocean recognised as setting the sulfate aerosol background, but its oxidation is complex. As a result representation in chemistry-climate models is greatly simplified. We develop and compare a new mechanism to existing mechanisms via a series of global and box model experiments. Our studies show our updated DMS scheme is a significant improvement but significant variance exists between mechanisms.
Ewa M. Bednarz, Ryan Hossaini, N. Luke Abraham, and Martyn P. Chipperfield
Geosci. Model Dev., 16, 6187–6209, https://doi.org/10.5194/gmd-16-6187-2023, https://doi.org/10.5194/gmd-16-6187-2023, 2023
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Development and performance of the new DEST chemistry scheme of UM–UKCA is described. The scheme extends the standard StratTrop scheme by including important updates to the halogen chemistry, thus allowing process-oriented studies of stratospheric ozone depletion and recovery, including impacts from both controlled long-lived ozone-depleting substances and emerging issues around uncontrolled, very short-lived substances. It will thus aid studies in support of future ozone assessment reports.
Nicola J. Warwick, Alex T. Archibald, Paul T. Griffiths, James Keeble, Fiona M. O'Connor, John A. Pyle, and Keith P. Shine
Atmos. Chem. Phys., 23, 13451–13467, https://doi.org/10.5194/acp-23-13451-2023, https://doi.org/10.5194/acp-23-13451-2023, 2023
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A chemistry–climate model has been used to explore the atmospheric response to changes in emissions of hydrogen and other species associated with a shift from fossil fuel to hydrogen use. Leakage of hydrogen results in indirect global warming, offsetting greenhouse gas emission reductions from reduced fossil fuel use. To maximise the benefit of hydrogen as an energy source, hydrogen leakage and emissions of methane, carbon monoxide and nitrogen oxides should be minimised.
Monali Borthakur, Miriam Sinnhuber, Alexandra Laeng, Thomas Reddmann, Peter Braesicke, Gabriele Stiller, Thomas von Clarmann, Bernd Funke, Ilya Usoskin, Jan Maik Wissing, and Olesya Yakovchuk
Atmos. Chem. Phys., 23, 12985–13013, https://doi.org/10.5194/acp-23-12985-2023, https://doi.org/10.5194/acp-23-12985-2023, 2023
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Reduced ozone levels resulting from ozone depletion mean more exposure to UV radiation, which has various effects on human health. We analysed solar events to see what influence it has on the chemistry of Earth's atmosphere and how this atmospheric chemistry change can affect the ozone. To do this, we used an atmospheric model considering only chemistry and compared it with satellite data. The focus was mainly on the contribution of chlorine, and we found about 10 %–20 % ozone loss due to that.
Marina Friedel, Gabriel Chiodo, Timofei Sukhodolov, James Keeble, Thomas Peter, Svenja Seeber, Andrea Stenke, Hideharu Akiyoshi, Eugene Rozanov, David Plummer, Patrick Jöckel, Guang Zeng, Olaf Morgenstern, and Béatrice Josse
Atmos. Chem. Phys., 23, 10235–10254, https://doi.org/10.5194/acp-23-10235-2023, https://doi.org/10.5194/acp-23-10235-2023, 2023
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Previously, it has been suggested that springtime Arctic ozone depletion might worsen in the coming decades due to climate change, which might counteract the effect of reduced ozone-depleting substances. Here, we show with different chemistry–climate models that springtime Arctic ozone depletion will likely decrease in the future. Further, we explain why models show a large spread in the projected development of Arctic ozone depletion and use the model spread to constrain future projections.
Mingzhao Liu, Lars Hoffmann, Sabine Griessbach, Zhongyin Cai, Yi Heng, and Xue Wu
Geosci. Model Dev., 16, 5197–5217, https://doi.org/10.5194/gmd-16-5197-2023, https://doi.org/10.5194/gmd-16-5197-2023, 2023
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We introduce new and revised chemistry and physics modules in the Massive-Parallel Trajectory Calculations (MPTRAC) Lagrangian transport model aiming to improve the representation of volcanic SO2 transport and depletion. We test these modules in a case study of the Ambae eruption in July 2018 in which the SO2 plume underwent wet removal and convection. The lifetime of SO2 shows highly variable and complex dependencies on the atmospheric conditions at different release heights.
Raghul Parthipan, Hannah M. Christensen, J. Scott Hosking, and Damon J. Wischik
Geosci. Model Dev., 16, 4501–4519, https://doi.org/10.5194/gmd-16-4501-2023, https://doi.org/10.5194/gmd-16-4501-2023, 2023
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How can we create better climate models? We tackle this by proposing a data-driven successor to the existing approach for capturing key temporal trends in climate models. We combine probability, allowing us to represent uncertainty, with machine learning, a technique to learn relationships from data which are undiscoverable to humans. Our model is often superior to existing baselines when tested in a simple atmospheric simulation.
Laura J. Wilcox, Robert J. Allen, Bjørn H. Samset, Massimo A. Bollasina, Paul T. Griffiths, James Keeble, Marianne T. Lund, Risto Makkonen, Joonas Merikanto, Declan O'Donnell, David J. Paynter, Geeta G. Persad, Steven T. Rumbold, Toshihiko Takemura, Kostas Tsigaridis, Sabine Undorf, and Daniel M. Westervelt
Geosci. Model Dev., 16, 4451–4479, https://doi.org/10.5194/gmd-16-4451-2023, https://doi.org/10.5194/gmd-16-4451-2023, 2023
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Changes in anthropogenic aerosol emissions have strongly contributed to global and regional climate change. However, the size of these regional impacts and the way they arise are still uncertain. With large changes in aerosol emissions a possibility over the next few decades, it is important to better quantify the potential role of aerosol in future regional climate change. The Regional Aerosol Model Intercomparison Project will deliver experiments designed to facilitate this.
Lars Hoffmann, Paul Konopka, Jan Clemens, and Bärbel Vogel
Atmos. Chem. Phys., 23, 7589–7609, https://doi.org/10.5194/acp-23-7589-2023, https://doi.org/10.5194/acp-23-7589-2023, 2023
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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.
Christian Scharun, Roland Ruhnke, and Peter Braesicke
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-91, https://doi.org/10.5194/gmd-2023-91, 2023
Publication in GMD not foreseen
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The identification and quantification of greenhouse gas (GHG) emissions is an important task for monitoring mitigation strategies under climate change. With RICHARD 1.0, we developed a novel approach using spatiotemporal proxy data and a selection algorithm to detect GHG emission hotspots. By using a one year dataset of global climate model output we showed that RICHARD is able to determine and quantify the source strengths of GHG emission hotspots much more precisely than conventional methods.
Maria Rosa Russo, Brian John Kerridge, Nathan Luke Abraham, James Keeble, Barry Graham Latter, Richard Siddans, James Weber, Paul Thomas Griffiths, John Adrian Pyle, and Alexander Thomas Archibald
Atmos. Chem. Phys., 23, 6169–6196, https://doi.org/10.5194/acp-23-6169-2023, https://doi.org/10.5194/acp-23-6169-2023, 2023
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Tropospheric ozone is an important component of the Earth system as it can affect both climate and air quality. In this work we use observed tropospheric ozone derived from satellite observations and compare it to tropospheric ozone from model simulations. Our aim is to investigate recent changes (2005–2018) in tropospheric ozone in the North Atlantic region and to understand what factors are driving such changes.
Scott Archer-Nicholls, Rachel Allen, Nathan L. Abraham, Paul T. Griffiths, and Alex T. Archibald
Atmos. Chem. Phys., 23, 5801–5813, https://doi.org/10.5194/acp-23-5801-2023, https://doi.org/10.5194/acp-23-5801-2023, 2023
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The nitrate radical is a major oxidant at nighttime, but much less is known about it than about the other oxidants ozone and OH. We use Earth system model calculations to show how the nitrate radical has changed in abundance from 1850–2014 and to 2100 under a range of different climate and emission scenarios. Depending on the emissions and climate scenario, significant increases are projected with implications for the oxidation of volatile organic compounds and the formation of fine aerosol.
Fouzia Fahrin, Daniel C. Jones, Yan Wu, James Keeble, and Alexander T. Archibald
Atmos. Chem. Phys., 23, 3609–3627, https://doi.org/10.5194/acp-23-3609-2023, https://doi.org/10.5194/acp-23-3609-2023, 2023
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We use a machine learning technique called Gaussian mixture modeling (GMM) to classify vertical ozone profiles into groups based on how the ozone concentration changes with pressure. Even though the GMM algorithm was not provided with spatial information, the classes are geographically coherent. We also detect signatures of tropical broadening in UKESM1 future climate scenarios. GMM may be useful for understanding ozone structures in modeled and observed datasets.
Eric Förster, Harald Bönisch, Marco Neumaier, Florian Obersteiner, Andreas Zahn, Andreas Hilboll, Anna B. Kalisz Hedegaard, Nikos Daskalakis, Alexandros Panagiotis Poulidis, Mihalis Vrekoussis, Michael Lichtenstern, and Peter Braesicke
Atmos. Chem. Phys., 23, 1893–1918, https://doi.org/10.5194/acp-23-1893-2023, https://doi.org/10.5194/acp-23-1893-2023, 2023
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The airborne megacity campaign EMeRGe provided an unprecedented amount of trace gas measurements. We combine measured volatile organic compounds (VOCs) with trajectory-modelled emission uptakes to identify potential source regions of pollution. We also characterise the chemical fingerprints (e.g. biomass burning and anthropogenic signatures) of the probed air masses to corroborate the contributing source regions. Our approach is the first large-scale study of VOCs originating from megacities.
Ewa M. Bednarz, Daniele Visioni, Ben Kravitz, Andy Jones, James M. Haywood, Jadwiga Richter, Douglas G. MacMartin, and Peter Braesicke
Atmos. Chem. Phys., 23, 687–709, https://doi.org/10.5194/acp-23-687-2023, https://doi.org/10.5194/acp-23-687-2023, 2023
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Building on Part 1 of this two-part study, we demonstrate the role of biases in climatological circulation and specific aspects of model microphysics in driving the differences in simulated sulfate distributions amongst three Earth system models. We then characterize the simulated changes in stratospheric and free-tropospheric temperatures, ozone, water vapor, and large-scale circulation, elucidating the role of the above aspects in the surface responses discussed in Part 1.
Reimar Bauer, Jens-Uwe Grooß, Jörn Ungermann, May Bär, Markus Geldenhuys, and Lars Hoffmann
Geosci. Model Dev., 15, 8983–8997, https://doi.org/10.5194/gmd-15-8983-2022, https://doi.org/10.5194/gmd-15-8983-2022, 2022
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The Mission Support System (MSS) is an open source software package that has been used for planning flight tracks of scientific aircraft in multiple measurement campaigns during the last decade. Here, we describe the MSS software and its use during the SouthTRAC measurement campaign in 2019. As an example for how the MSS software is used in conjunction with many datasets, we describe the planning of a single flight probing orographic gravity waves propagating up into the lower mesosphere.
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, https://doi.org/10.5194/gmd-15-7471-2022, https://doi.org/10.5194/gmd-15-7471-2022, 2022
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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.
Jeremy Carter, Amber Leeson, Andrew Orr, Christoph Kittel, and J. Melchior van Wessem
The Cryosphere, 16, 3815–3841, https://doi.org/10.5194/tc-16-3815-2022, https://doi.org/10.5194/tc-16-3815-2022, 2022
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Climate models provide valuable information for studying processes such as the collapse of ice shelves over Antarctica which impact estimates of sea level rise. This paper examines variability across climate simulations over Antarctica for fields including snowfall, temperature and melt. Significant systematic differences between outputs are found, occurring at both large and fine spatial scales across Antarctica. Results are important for future impact assessments and model development.
Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
Atmos. Chem. Phys., 22, 12331–12352, https://doi.org/10.5194/acp-22-12331-2022, https://doi.org/10.5194/acp-22-12331-2022, 2022
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Surface ozone can decrease plant productivity and impair human health. In this study, we evaluate the change in surface ozone due to climate change over South America and Africa using Earth system models. We find that if the climate were to change according to the worst-case scenario used here, models predict that forested areas in biomass burning locations and urban populations will be at increasing risk of ozone exposure, but other areas will experience a climate benefit.
Ewa M. Bednarz, Ryan Hossaini, Martyn P. Chipperfield, N. Luke Abraham, and Peter Braesicke
Atmos. Chem. Phys., 22, 10657–10676, https://doi.org/10.5194/acp-22-10657-2022, https://doi.org/10.5194/acp-22-10657-2022, 2022
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Atmospheric impacts of chlorinated very short-lived substances (Cl-VSLS) over the first two decades of the 21st century are assessed using the UM-UKCA chemistry–climate model. Stratospheric input of Cl from Cl-VSLS is estimated at ~130 ppt in 2019. The use of model set-up with constrained meteorology significantly increases the abundance of Cl-VSLS in the lower stratosphere relative to the free-running set-up. The growth in Cl-VSLS emissions significantly impacted recent HCl and COCl2 trends.
Neil P. Hindley, Nicholas J. Mitchell, Neil Cobbett, Anne K. Smith, Dave C. Fritts, Diego Janches, Corwin J. Wright, and Tracy Moffat-Griffin
Atmos. Chem. Phys., 22, 9435–9459, https://doi.org/10.5194/acp-22-9435-2022, https://doi.org/10.5194/acp-22-9435-2022, 2022
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We present observations of winds in the mesosphere and lower thermosphere (MLT) from a recently installed meteor radar on the remote island of South Georgia (54° S, 36° W). We characterise mean winds, tides, planetary waves, and gravity waves in the MLT at this location and compare our measured winds with a leading climate model. We find that the observed wintertime winds are unexpectedly reversed from model predictions, probably because of missing impacts of secondary gravity waves in the model.
Zhongyin Cai, Sabine Griessbach, and Lars Hoffmann
Atmos. Chem. Phys., 22, 6787–6809, https://doi.org/10.5194/acp-22-6787-2022, https://doi.org/10.5194/acp-22-6787-2022, 2022
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Using AIRS and TROPOMI sulfur dioxide retrievals and the Lagrangian transport model MPTRAC, we present an improved reconstruction of injection parameters of the 2019 Raikoke eruption. Reconstructions agree well between using AIRS nighttime and TROPOMI daytime retrievals, showing the potential of our approach to create a long-term volcanic sulfur dioxide inventory from nearly 20 years of AIRS retrievals.
Ling Zou, Sabine Griessbach, Lars Hoffmann, and Reinhold Spang
Atmos. Chem. Phys., 22, 6677–6702, https://doi.org/10.5194/acp-22-6677-2022, https://doi.org/10.5194/acp-22-6677-2022, 2022
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Ice clouds in the stratosphere (SICs) greatly affect the water vapor balance and radiation budget in the upper troposphere and lower stratosphere (UTLS). We quantified the global SICs and analyzed their relationships with tropopause temperature, double tropopauses, UTLS clouds, gravity waves, and stratospheric aerosols. The correlations between SICs and all abovementioned processes indicate that the occurrence of and variability in SICs are spatiotemporally dependent on different processes.
Phoebe Noble, Neil Hindley, Corwin Wright, Chihoko Cullens, Scott England, Nicholas Pedatella, Nicholas Mitchell, and Tracy Moffat-Griffin
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-150, https://doi.org/10.5194/acp-2022-150, 2022
Revised manuscript not accepted
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We use long term radar data and the WACCM-X model to study the impact of dynamical phenomena, including the 11-year solar cycle, ENSO, QBO and SAM, on Antarctic mesospheric winds. We find that in summer, the zonal wind (both observationally and in the model) is strongly correlated with the solar cycle. We also see important differences in the results from the other processes. In addition we find important and large biases in the winter model zonal winds relative to the observations.
Lars Hoffmann, Paul F. Baumeister, Zhongyin Cai, Jan Clemens, Sabine Griessbach, Gebhard Günther, Yi Heng, Mingzhao Liu, Kaveh Haghighi Mood, Olaf Stein, Nicole Thomas, Bärbel Vogel, Xue Wu, and Ling Zou
Geosci. Model Dev., 15, 2731–2762, https://doi.org/10.5194/gmd-15-2731-2022, https://doi.org/10.5194/gmd-15-2731-2022, 2022
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We describe the new version (2.2) of the Lagrangian transport model MPTRAC, which has been ported for application on GPUs. The model was verified by comparing kinematic trajectories and synthetic tracer simulations for the free troposphere and stratosphere from GPUs and CPUs. Benchmarking showed a speed-up of a factor of 16 of GPU-enabled simulations compared to CPU-only runs, indicating the great potential of applying GPUs for Lagrangian transport simulations on upcoming HPC systems.
Lars Hoffmann and Reinhold Spang
Atmos. Chem. Phys., 22, 4019–4046, https://doi.org/10.5194/acp-22-4019-2022, https://doi.org/10.5194/acp-22-4019-2022, 2022
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We present an intercomparison of 2009–2018 lapse rate tropopause characteristics as derived from ECMWF's ERA5 and ERA-Interim reanalyses. Large-scale features are similar, but ERA5 shows notably larger variability, which we mainly attribute to UTLS temperature fluctuations due to gravity waves being better resolved by ECMWF's IFS forecast model. Following evaluation with radiosondes and GPS data, we conclude ERA5 will be a more suitable asset for tropopause-related studies in future work.
Paul F. Baumeister and Lars Hoffmann
Geosci. Model Dev., 15, 1855–1874, https://doi.org/10.5194/gmd-15-1855-2022, https://doi.org/10.5194/gmd-15-1855-2022, 2022
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The efficiency of the numerical simulation of radiative transport is shown on modern server-class graphics cards (GPUs). The low-cost prefactor on GPUs compared to general-purpose processors (CPUs) enables future large retrieval campaigns for multi-channel data from infrared sounders aboard low-orbit satellites. The validated research software JURASSIC is available in the public domain.
Florian Haenel, Wolfgang Woiwode, Jennifer Buchmüller, Felix Friedl-Vallon, Michael Höpfner, Sören Johansson, Farahnaz Khosrawi, Oliver Kirner, Anne Kleinert, Hermann Oelhaf, Johannes Orphal, Roland Ruhnke, Björn-Martin Sinnhuber, Jörn Ungermann, Michael Weimer, and Peter Braesicke
Atmos. Chem. Phys., 22, 2843–2870, https://doi.org/10.5194/acp-22-2843-2022, https://doi.org/10.5194/acp-22-2843-2022, 2022
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We compare remote sensing observations of H2O, O3, HNO3 and clouds in the upper troposphere–lowermost stratosphere during an Arctic winter long-range research flight with simulations by two different state-of-the-art model systems. We find good agreement for dynamical structures, trace gas distributions and clouds. We investigate model biases and sensitivities, with the goal of aiding model development and improving our understanding of processes in the upper troposphere–lowermost stratosphere.
Nicolaj Hansen, Sebastian B. Simonsen, Fredrik Boberg, Christoph Kittel, Andrew Orr, Niels Souverijns, J. Melchior van Wessem, and Ruth Mottram
The Cryosphere, 16, 711–718, https://doi.org/10.5194/tc-16-711-2022, https://doi.org/10.5194/tc-16-711-2022, 2022
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We investigate the impact of different ice masks when modelling surface mass balance over Antarctica. We used ice masks and data from five of the most used regional climate models and a common mask. We see large disagreement between the ice masks, which has a large impact on the surface mass balance, especially around the Antarctic Peninsula and some of the largest glaciers. We suggest a solution for creating a new, up-to-date, high-resolution ice mask that can be used in Antarctic modelling.
Anna Vaughan, Will Tebbutt, J. Scott Hosking, and Richard E. Turner
Geosci. Model Dev., 15, 251–268, https://doi.org/10.5194/gmd-15-251-2022, https://doi.org/10.5194/gmd-15-251-2022, 2022
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We develop a new method for climate downscaling, i.e. transforming low-resolution climate model output to high-resolution projections, using a deep-learning model known as a convolutional conditional neural process. This model is shown to outperform an ensemble of baseline methods for downscaling daily maximum temperature and precipitation and provides a powerful new downscaling framework for climate impact studies.
Christopher J. Diekmann, Matthias Schneider, Benjamin Ertl, Frank Hase, Omaira García, Farahnaz Khosrawi, Eliezer Sepúlveda, Peter Knippertz, and Peter Braesicke
Earth Syst. Sci. Data, 13, 5273–5292, https://doi.org/10.5194/essd-13-5273-2021, https://doi.org/10.5194/essd-13-5273-2021, 2021
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The joint analysis of different stable water isotopes in water vapour is a powerful tool for investigating atmospheric moisture pathways. This paper presents a novel global and multi-annual dataset of H2O and HDO in mid-tropospheric water vapour by using data from the satellite sensor Metop/IASI. Due to its unique combination of coverage and resolution in space and time, this dataset is highly promising for studying the hydrological cycle and its representation in weather and climate models.
Anthony C. Jones, Adrian Hill, Samuel Remy, N. Luke Abraham, Mohit Dalvi, Catherine Hardacre, Alan J. Hewitt, Ben Johnson, Jane P. Mulcahy, and Steven T. Turnock
Atmos. Chem. Phys., 21, 15901–15927, https://doi.org/10.5194/acp-21-15901-2021, https://doi.org/10.5194/acp-21-15901-2021, 2021
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Ammonium nitrate is hard to model because it forms and evaporates rapidly. One approach is to relate its equilibrium concentration to temperature, humidity, and the amount of nitric acid and ammonia gases. Using this approach, we limit the rate at which equilibrium is reached using various condensation rates in a climate model. We show that ammonium nitrate concentrations are highly sensitive to the condensation rate. Our results will help improve the representation of nitrate in climate models.
Corwin J. Wright, Neil P. Hindley, M. Joan Alexander, Laura A. Holt, and Lars Hoffmann
Atmos. Meas. Tech., 14, 5873–5886, https://doi.org/10.5194/amt-14-5873-2021, https://doi.org/10.5194/amt-14-5873-2021, 2021
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Measuring atmospheric gravity waves in low vertical-resolution data is technically challenging, especially when the waves are significantly longer in the vertical than in the length of the measurement domain. We introduce and demonstrate a modification to the existing Stockwell transform methods of characterising these waves that address these problems, with no apparent reduction in the other capabilities of the technique.
James Weber, Scott Archer-Nicholls, Nathan Luke Abraham, Youngsub M. Shin, Thomas J. Bannan, Carl J. Percival, Asan Bacak, Paulo Artaxo, Michael Jenkin, M. Anwar H. Khan, Dudley E. Shallcross, Rebecca H. Schwantes, Jonathan Williams, and Alex T. Archibald
Geosci. Model Dev., 14, 5239–5268, https://doi.org/10.5194/gmd-14-5239-2021, https://doi.org/10.5194/gmd-14-5239-2021, 2021
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The new mechanism CRI-Strat 2 features state-of-the-art isoprene chemistry not previously available in UKCA and improves UKCA's ability to reproduce observed concentrations of isoprene, monoterpenes, and OH in tropical regions. The enhanced ability to model isoprene, the most widely emitted non-methane volatile organic compound (VOC), will allow understanding of how isoprene and other biogenic VOCs affect atmospheric composition and, through biosphere–atmosphere feedbacks, climate change.
Ruth Mottram, Nicolaj Hansen, Christoph Kittel, J. Melchior van Wessem, Cécile Agosta, Charles Amory, Fredrik Boberg, Willem Jan van de Berg, Xavier Fettweis, Alexandra Gossart, Nicole P. M. van Lipzig, Erik van Meijgaard, Andrew Orr, Tony Phillips, Stuart Webster, Sebastian B. Simonsen, and Niels Souverijns
The Cryosphere, 15, 3751–3784, https://doi.org/10.5194/tc-15-3751-2021, https://doi.org/10.5194/tc-15-3751-2021, 2021
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We compare the calculated surface mass budget (SMB) of Antarctica in five different regional climate models. On average ~ 2000 Gt of snow accumulates annually, but different models vary by ~ 10 %, a difference equivalent to ± 0.5 mm of global sea level rise. All models reproduce observed weather, but there are large differences in regional patterns of snowfall, especially in areas with very few observations, giving greater uncertainty in Antarctic mass budget than previously identified.
Ling Zou, Lars Hoffmann, Sabine Griessbach, Reinhold Spang, and Lunche Wang
Atmos. Chem. Phys., 21, 10457–10475, https://doi.org/10.5194/acp-21-10457-2021, https://doi.org/10.5194/acp-21-10457-2021, 2021
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Ice clouds in the lowermost stratosphere (SICs) have important impacts on the radiation budget and climate change. We quantified the occurrence of SICs over North America and analysed its relations with convective systems and gravity waves to investigate potential formation mechanisms of SICs. Deep convection is proved to be the primary factor linked to the occurrence of SICs over North America.
Michael Weimer, Jennifer Buchmüller, Lars Hoffmann, Ole Kirner, Beiping Luo, Roland Ruhnke, Michael Steiner, Ines Tritscher, and Peter Braesicke
Atmos. Chem. Phys., 21, 9515–9543, https://doi.org/10.5194/acp-21-9515-2021, https://doi.org/10.5194/acp-21-9515-2021, 2021
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We show that we are able to directly simulate polar stratospheric clouds formed locally in a mountain wave and represent their effect on the ozone chemistry with the global atmospheric chemistry model ICON-ART. Thus, we show the first simulations that close the gap between directly resolved mountain-wave-induced polar stratospheric clouds and their representation at coarse global resolutions.
John Staunton-Sykes, Thomas J. Aubry, Youngsub M. Shin, James Weber, Lauren R. Marshall, Nathan Luke Abraham, Alex Archibald, and Anja Schmidt
Atmos. Chem. Phys., 21, 9009–9029, https://doi.org/10.5194/acp-21-9009-2021, https://doi.org/10.5194/acp-21-9009-2021, 2021
Matthew J. Griffith, Shaun M. Dempsey, David R. Jackson, Tracy Moffat-Griffin, and Nicholas J. Mitchell
Ann. Geophys., 39, 487–514, https://doi.org/10.5194/angeo-39-487-2021, https://doi.org/10.5194/angeo-39-487-2021, 2021
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There is great scientific interest in extending atmospheric models upwards to include the upper atmosphere. The Met Office’s Unified Model has recently been successfully extended to include this region. Atmospheric tides are an important driver of atmospheric motion at these greater heights. This paper provides a first comparison of winds and tides produced by the new extended model with meteor radar observations, comparing key tidal properties and discussing their similarities and differences.
Neil P. Hindley, Corwin J. Wright, Alan M. Gadian, Lars Hoffmann, John K. Hughes, David R. Jackson, John C. King, Nicholas J. Mitchell, Tracy Moffat-Griffin, Andrew C. Moss, Simon B. Vosper, and Andrew N. Ross
Atmos. Chem. Phys., 21, 7695–7722, https://doi.org/10.5194/acp-21-7695-2021, https://doi.org/10.5194/acp-21-7695-2021, 2021
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One limitation of numerical atmospheric models is spatial resolution. For atmospheric gravity waves (GWs) generated over small mountainous islands, the driving effect of these waves on atmospheric circulations can be underestimated. Here we use a specialised high-resolution model over South Georgia island to compare simulated stratospheric GWs to colocated 3-D satellite observations. We find reasonable model agreement with observations, with some GW amplitudes much larger than expected.
Andrew Orr, Hua Lu, Patrick Martineau, Edwin P. Gerber, Gareth J. Marshall, and Thomas J. Bracegirdle
Atmos. Chem. Phys., 21, 7451–7472, https://doi.org/10.5194/acp-21-7451-2021, https://doi.org/10.5194/acp-21-7451-2021, 2021
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Reanalysis datasets combine observations and weather forecast simulations to create our best estimate of the state of the atmosphere and are important for climate monitoring. Differences in the technical details of these products mean that they may give different results. This study therefore examined how changes associated with the so-called Antarctic ozone hole are represented, which is one of the most important climate changes in recent decades, and showed that they were broadly consistent.
Ashok K. Luhar, Ian E. Galbally, Matthew T. Woodhouse, and Nathan Luke Abraham
Atmos. Chem. Phys., 21, 7053–7082, https://doi.org/10.5194/acp-21-7053-2021, https://doi.org/10.5194/acp-21-7053-2021, 2021
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Lightning-generated nitrogen oxides (LNOx) greatly influence tropospheric photochemistry. The most common parameterisation of lightning flash rate used to calculate LNOx in global composition models underestimates measurements over the ocean by a factor of 20–25. We formulate and validate an alternative parameterisation to remedy this problem. The new scheme causes an increase in the ozone burden by 8.5 % and the hydroxyl radical by 13 %, and these have implications for climate and air quality.
Irene Bartolome Garcia, Reinhold Spang, Jörn Ungermann, Sabine Griessbach, Martina Krämer, Michael Höpfner, and Martin Riese
Atmos. Meas. Tech., 14, 3153–3168, https://doi.org/10.5194/amt-14-3153-2021, https://doi.org/10.5194/amt-14-3153-2021, 2021
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Cirrus clouds contribute to the general radiation budget of the Earth. Measuring optically thin clouds is challenging but the IR limb sounder GLORIA possesses the necessary technical characteristics to make it possible. This study analyses data from the WISE campaign obtained with GLORIA. We developed a cloud detection method and derived characteristics of the observed cirrus-like cloud top, cloud bottom or position with respect to the tropopause.
James Keeble, Birgit Hassler, Antara Banerjee, Ramiro Checa-Garcia, Gabriel Chiodo, Sean Davis, Veronika Eyring, Paul T. Griffiths, Olaf Morgenstern, Peer Nowack, Guang Zeng, Jiankai Zhang, Greg Bodeker, Susannah Burrows, Philip Cameron-Smith, David Cugnet, Christopher Danek, Makoto Deushi, Larry W. Horowitz, Anne Kubin, Lijuan Li, Gerrit Lohmann, Martine Michou, Michael J. Mills, Pierre Nabat, Dirk Olivié, Sungsu Park, Øyvind Seland, Jens Stoll, Karl-Hermann Wieners, and Tongwen Wu
Atmos. Chem. Phys., 21, 5015–5061, https://doi.org/10.5194/acp-21-5015-2021, https://doi.org/10.5194/acp-21-5015-2021, 2021
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Stratospheric ozone and water vapour are key components of the Earth system; changes to both have important impacts on global and regional climate. We evaluate changes to these species from 1850 to 2100 in the new generation of CMIP6 models. There is good agreement between the multi-model mean and observations, although there is substantial variation between the individual models. The future evolution of both ozone and water vapour is strongly dependent on the assumed future emissions scenario.
Ananth Ranjithkumar, Hamish Gordon, Christina Williamson, Andrew Rollins, Kirsty Pringle, Agnieszka Kupc, Nathan Luke Abraham, Charles Brock, and Ken Carslaw
Atmos. Chem. Phys., 21, 4979–5014, https://doi.org/10.5194/acp-21-4979-2021, https://doi.org/10.5194/acp-21-4979-2021, 2021
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The effect aerosols have on climate can be better understood by studying their vertical and spatial distribution throughout the atmosphere. We use observation data from the ATom campaign and evaluate the vertical profile of aerosol number concentration, sulfur dioxide and condensation sink using the UKESM (UK Earth System Model). We identify uncertainties in key atmospheric processes that help improve their theoretical representation in global climate models.
Paul T. Griffiths, Lee T. Murray, Guang Zeng, Youngsub Matthew Shin, N. Luke Abraham, Alexander T. Archibald, Makoto Deushi, Louisa K. Emmons, Ian E. Galbally, Birgit Hassler, Larry W. Horowitz, James Keeble, Jane Liu, Omid Moeini, Vaishali Naik, Fiona M. O'Connor, Naga Oshima, David Tarasick, Simone Tilmes, Steven T. Turnock, Oliver Wild, Paul J. Young, and Prodromos Zanis
Atmos. Chem. Phys., 21, 4187–4218, https://doi.org/10.5194/acp-21-4187-2021, https://doi.org/10.5194/acp-21-4187-2021, 2021
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We analyse the CMIP6 Historical and future simulations for tropospheric ozone, a species which is important for many aspects of atmospheric chemistry. We show that the current generation of models agrees well with observations, being particularly successful in capturing trends in surface ozone and its vertical distribution in the troposphere. We analyse the factors that control ozone and show that they evolve over the period of the CMIP6 experiments.
Christoph Kalicinsky, Sabine Griessbach, and Reinhold Spang
Atmos. Meas. Tech., 14, 1893–1915, https://doi.org/10.5194/amt-14-1893-2021, https://doi.org/10.5194/amt-14-1893-2021, 2021
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For an airborne viewing geometry, radiative transfer simulations of infrared limb emission spectra in the presence of polar stratospheric clouds – nitric acid trihydrate (NAT), supercooled ternary solution, ice, and mixtures – were used to develop a size-sensitive NAT detection algorithm. Characteristic size-dependent spectral features in the 810–820 cm−1 region were exploited to subgroup the NAT into three size regimes: small NAT (≤ 1.0 μm), medium NAT (1.5–4.0 μm), and large NAT (≥ 3.5 μm).
Peter Sherman, Meng Gao, Shaojie Song, Alex T. Archibald, Nathan Luke Abraham, Jean-François Lamarque, Drew Shindell, Gregory Faluvegi, and Michael B. McElroy
Atmos. Chem. Phys., 21, 3593–3605, https://doi.org/10.5194/acp-21-3593-2021, https://doi.org/10.5194/acp-21-3593-2021, 2021
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The aims here are to assess the role of aerosols in India's monsoon precipitation and to determine the relative contributions from Chinese and Indian emissions using CMIP6 models. We find that increased sulfur emissions reduce precipitation, which is primarily dynamically driven due to spatial shifts in convection over the region. A significant increase in precipitation (up to ~ 20 %) is found only when both Indian and Chinese sulfate emissions are regulated.
Fiona M. O'Connor, N. Luke Abraham, Mohit Dalvi, Gerd A. Folberth, Paul T. Griffiths, Catherine Hardacre, Ben T. Johnson, Ron Kahana, James Keeble, Byeonghyeon Kim, Olaf Morgenstern, Jane P. Mulcahy, Mark Richardson, Eddy Robertson, Jeongbyn Seo, Sungbo Shim, João C. Teixeira, Steven T. Turnock, Jonny Williams, Andrew J. Wiltshire, Stephanie Woodward, and Guang Zeng
Atmos. Chem. Phys., 21, 1211–1243, https://doi.org/10.5194/acp-21-1211-2021, https://doi.org/10.5194/acp-21-1211-2021, 2021
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This paper calculates how changes in emissions and/or concentrations of different atmospheric constituents since the pre-industrial era have altered the Earth's energy budget at the present day using a metric called effective radiative forcing. The impact of land use change is also assessed. We find that individual contributions do not add linearly, and different Earth system interactions can affect the magnitude of the calculated effective radiative forcing.
Gillian D. Thornhill, William J. Collins, Ryan J. Kramer, Dirk Olivié, Ragnhild B. Skeie, Fiona M. O'Connor, Nathan Luke Abraham, Ramiro Checa-Garcia, Susanne E. Bauer, Makoto Deushi, Louisa K. Emmons, Piers M. Forster, Larry W. Horowitz, Ben Johnson, James Keeble, Jean-Francois Lamarque, Martine Michou, Michael J. Mills, Jane P. Mulcahy, Gunnar Myhre, Pierre Nabat, Vaishali Naik, Naga Oshima, Michael Schulz, Christopher J. Smith, Toshihiko Takemura, Simone Tilmes, Tongwen Wu, Guang Zeng, and Jie Zhang
Atmos. Chem. Phys., 21, 853–874, https://doi.org/10.5194/acp-21-853-2021, https://doi.org/10.5194/acp-21-853-2021, 2021
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This paper is a study of how different constituents in the atmosphere, such as aerosols and gases like methane and ozone, affect the energy balance in the atmosphere. Different climate models were run using the same inputs to allow an easy comparison of the results and to understand where the models differ. We found the effect of aerosols is to reduce warming in the atmosphere, but this effect varies between models. Reactions between gases are also important in affecting climate.
Gunter Stober, Diego Janches, Vivien Matthias, Dave Fritts, John Marino, Tracy Moffat-Griffin, Kathrin Baumgarten, Wonseok Lee, Damian Murphy, Yong Ha Kim, Nicholas Mitchell, and Scott Palo
Ann. Geophys., 39, 1–29, https://doi.org/10.5194/angeo-39-1-2021, https://doi.org/10.5194/angeo-39-1-2021, 2021
Jane P. Mulcahy, Colin Johnson, Colin G. Jones, Adam C. Povey, Catherine E. Scott, Alistair Sellar, Steven T. Turnock, Matthew T. Woodhouse, Nathan Luke Abraham, Martin B. Andrews, Nicolas Bellouin, Jo Browse, Ken S. Carslaw, Mohit Dalvi, Gerd A. Folberth, Matthew Glover, Daniel P. Grosvenor, Catherine Hardacre, Richard Hill, Ben Johnson, Andy Jones, Zak Kipling, Graham Mann, James Mollard, Fiona M. O'Connor, Julien Palmiéri, Carly Reddington, Steven T. Rumbold, Mark Richardson, Nick A. J. Schutgens, Philip Stier, Marc Stringer, Yongming Tang, Jeremy Walton, Stephanie Woodward, and Andrew Yool
Geosci. Model Dev., 13, 6383–6423, https://doi.org/10.5194/gmd-13-6383-2020, https://doi.org/10.5194/gmd-13-6383-2020, 2020
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Aerosols are an important component of the Earth system. Here, we comprehensively document and evaluate the aerosol schemes as implemented in the physical and Earth system models, HadGEM3-GC3.1 and UKESM1. This study provides a useful characterisation of the aerosol climatology in both models, facilitating the understanding of the numerous aerosol–climate interaction studies that will be conducted for CMIP6 and beyond.
Jörn Ungermann, Irene Bartolome, Sabine Griessbach, Reinhold Spang, Christian Rolf, Martina Krämer, Michael Höpfner, and Martin Riese
Atmos. Meas. Tech., 13, 7025–7045, https://doi.org/10.5194/amt-13-7025-2020, https://doi.org/10.5194/amt-13-7025-2020, 2020
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This study examines the potential of new IR limb imager instruments and tomographic methods for cloud detection purposes. Simple color-ratio-based methods are examined and compared against more involved nonlinear convex optimization. In a second part, 3-D measurements of the airborne limb sounder GLORIA taken during the Wave-driven ISentropic Exchange campaign are used to exemplarily derive the location and extent of small-scale cirrus clouds with high spatial accuracy.
Sandip S. Dhomse, Graham W. Mann, Juan Carlos Antuña Marrero, Sarah E. Shallcross, Martyn P. Chipperfield, Kenneth S. Carslaw, Lauren Marshall, N. Luke Abraham, and Colin E. Johnson
Atmos. Chem. Phys., 20, 13627–13654, https://doi.org/10.5194/acp-20-13627-2020, https://doi.org/10.5194/acp-20-13627-2020, 2020
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We confirm downward adjustment of SO2 emission to simulate the Pinatubo aerosol cloud with aerosol microphysics models. Similar adjustment is also needed to simulate the El Chichón and Agung volcanic cloud, indicating potential missing removal or vertical redistribution process in models. Important inhomogeneities in the CMIP6 forcing datasets after Agung and El Chichón eruptions are difficult to reconcile. Quasi-biennial oscillation plays an important role in modifying stratospheric warming.
Isabell Krisch, Manfred Ern, Lars Hoffmann, Peter Preusse, Cornelia Strube, Jörn Ungermann, Wolfgang Woiwode, and Martin Riese
Atmos. Chem. Phys., 20, 11469–11490, https://doi.org/10.5194/acp-20-11469-2020, https://doi.org/10.5194/acp-20-11469-2020, 2020
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In 2016, a scientific research flight above Scandinavia acquired various atmospheric data (temperature, gas composition, etc.). Through advanced 3-D reconstruction methods, a superposition of multiple gravity waves was identified. An in-depth analysis enabled the characterisation of these waves as well as the identification of their sources. This work will enable a better understanding of atmosphere dynamics and could lead to improved climate projections.
Matt Amos, Paul J. Young, J. Scott Hosking, Jean-François Lamarque, N. Luke Abraham, Hideharu Akiyoshi, Alexander T. Archibald, Slimane Bekki, Makoto Deushi, Patrick Jöckel, Douglas Kinnison, Ole Kirner, Markus Kunze, Marion Marchand, David A. Plummer, David Saint-Martin, Kengo Sudo, Simone Tilmes, and Yousuke Yamashita
Atmos. Chem. Phys., 20, 9961–9977, https://doi.org/10.5194/acp-20-9961-2020, https://doi.org/10.5194/acp-20-9961-2020, 2020
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We present an updated projection of Antarctic ozone hole recovery using an ensemble of chemistry–climate models. To do so, we employ a method, more advanced and skilful than the current multi-model mean standard, which is applicable to other ensemble analyses. It calculates the performance and similarity of the models, which we then use to weight the model. Calculating model similarity allows us to account for models which are constructed from similar components.
Ling Zou, Sabine Griessbach, Lars Hoffmann, Bing Gong, and Lunche Wang
Atmos. Chem. Phys., 20, 9939–9959, https://doi.org/10.5194/acp-20-9939-2020, https://doi.org/10.5194/acp-20-9939-2020, 2020
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Cirrus clouds appearing in the upper troposphere and lower stratosphere have important impacts on the radiation budget and climate change. We revisited global stratospheric cirrus clouds with CALIPSO and for the first time with MIPAS satellite observations. Stratospheric cirrus clouds related to deep convection are frequently detected in the tropics. At middle latitudes, MIPAS detects more than twice as many stratospheric cirrus clouds due to higher detection sensitivity.
Rebecca Dell, Neil Arnold, Ian Willis, Alison Banwell, Andrew Williamson, Hamish Pritchard, and Andrew Orr
The Cryosphere, 14, 2313–2330, https://doi.org/10.5194/tc-14-2313-2020, https://doi.org/10.5194/tc-14-2313-2020, 2020
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A semi-automated method is developed from pre-existing work to track surface water bodies across Antarctic ice shelves over time, using data from Sentinel-2 and Landsat 8. This method is applied to the Nivlisen Ice Shelf for the 2016–2017 melt season. The results reveal two large linear meltwater systems, which hold 63 % of the peak total surface meltwater volume on 26 January 2017. These meltwater systems migrate towards the ice shelf front as the melt season progresses.
Rocco Sedona, Lars Hoffmann, Reinhold Spang, Gabriele Cavallaro, Sabine Griessbach, Michael Höpfner, Matthias Book, and Morris Riedel
Atmos. Meas. Tech., 13, 3661–3682, https://doi.org/10.5194/amt-13-3661-2020, https://doi.org/10.5194/amt-13-3661-2020, 2020
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Polar stratospheric clouds (PSCs) play a key role in polar ozone depletion in the stratosphere. In this paper, we explore the potential of applying machine learning (ML) methods to classify PSC observations of infrared spectra to classify PSC types. ML methods have proved to reach results in line with those obtained using well-established approaches. Among the considered ML methods, random forest (RF) seems to be the most promising one, being able to produce explainable classification results.
James Keeble, N. Luke Abraham, Alexander T. Archibald, Martyn P. Chipperfield, Sandip Dhomse, Paul T. Griffiths, and John A. Pyle
Atmos. Chem. Phys., 20, 7153–7166, https://doi.org/10.5194/acp-20-7153-2020, https://doi.org/10.5194/acp-20-7153-2020, 2020
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The Montreal Protocol was agreed in 1987 to limit and then stop the production of man-made CFCs, which destroy stratospheric ozone. As a result, the atmospheric abundances of CFCs are now declining in the atmosphere. However, the atmospheric abundance of CFC-11 is not declining as expected under complete compliance with the Montreal Protocol. Using the UM-UKCA chemistry–climate model, we explore the impact of future unregulated production of CFC-11 on ozone recovery.
Clara Orbe, David A. Plummer, Darryn W. Waugh, Huang Yang, Patrick Jöckel, Douglas E. Kinnison, Beatrice Josse, Virginie Marecal, Makoto Deushi, Nathan Luke Abraham, Alexander T. Archibald, Martyn P. Chipperfield, Sandip Dhomse, Wuhu Feng, and Slimane Bekki
Atmos. Chem. Phys., 20, 3809–3840, https://doi.org/10.5194/acp-20-3809-2020, https://doi.org/10.5194/acp-20-3809-2020, 2020
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Atmospheric composition is strongly influenced by global-scale winds that are not always properly simulated in computer models. A common approach to correct for this bias is to relax or
nudgeto the observed winds. Here we systematically evaluate how well this technique performs across a large suite of chemistry–climate models in terms of its ability to reproduce key aspects of both the tropospheric and stratospheric circulations.
Alexander T. Archibald, Fiona M. O'Connor, Nathan Luke Abraham, Scott Archer-Nicholls, Martyn P. Chipperfield, Mohit Dalvi, Gerd A. Folberth, Fraser Dennison, Sandip S. Dhomse, Paul T. Griffiths, Catherine Hardacre, Alan J. Hewitt, Richard S. Hill, Colin E. Johnson, James Keeble, Marcus O. Köhler, Olaf Morgenstern, Jane P. Mulcahy, Carlos Ordóñez, Richard J. Pope, Steven T. Rumbold, Maria R. Russo, Nicholas H. Savage, Alistair Sellar, Marc Stringer, Steven T. Turnock, Oliver Wild, and Guang Zeng
Geosci. Model Dev., 13, 1223–1266, https://doi.org/10.5194/gmd-13-1223-2020, https://doi.org/10.5194/gmd-13-1223-2020, 2020
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Here we present a description and evaluation of the UKCA stratosphere–troposphere chemistry scheme (StratTrop vn 1.0) implemented in the UK Earth System Model (UKESM1). UKCA StratTrop represents a substantial step forward compared to previous versions of UKCA. We show here that it is fully suited to the challenges of representing interactions in a coupled Earth system model and identify key areas and components for future development that will make it even better in the future.
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, https://doi.org/10.5194/amt-13-1243-2020, https://doi.org/10.5194/amt-13-1243-2020, 2020
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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.
Neil P. Hindley, Corwin J. Wright, Nathan D. Smith, Lars Hoffmann, Laura A. Holt, M. Joan Alexander, Tracy Moffat-Griffin, and Nicholas J. Mitchell
Atmos. Chem. Phys., 19, 15377–15414, https://doi.org/10.5194/acp-19-15377-2019, https://doi.org/10.5194/acp-19-15377-2019, 2019
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In this study, a 3–D Stockwell transform is applied to AIRS–Aqua satellite observations in the first extended 3–D study of stratospheric gravity waves over the Southern Ocean during winter. A dynamic environment is revealed that contains some of the most intense gravity wave sources on Earth. A particularly striking result is a large–scale meridional convergence of gravity wave momentum flux towards latitudes near 60 °S, something which is not normally considered in model parameterisations.
Yuanhong Zhao, Marielle Saunois, Philippe Bousquet, Xin Lin, Antoine Berchet, Michaela I. Hegglin, Josep G. Canadell, Robert B. Jackson, Didier A. Hauglustaine, Sophie Szopa, Ann R. Stavert, Nathan Luke Abraham, Alex T. Archibald, Slimane Bekki, Makoto Deushi, Patrick Jöckel, Béatrice Josse, Douglas Kinnison, Ole Kirner, Virginie Marécal, Fiona M. O'Connor, David A. Plummer, Laura E. Revell, Eugene Rozanov, Andrea Stenke, Sarah Strode, Simone Tilmes, Edward J. Dlugokencky, and Bo Zheng
Atmos. Chem. Phys., 19, 13701–13723, https://doi.org/10.5194/acp-19-13701-2019, https://doi.org/10.5194/acp-19-13701-2019, 2019
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The role of hydroxyl radical changes in methane trends is debated, hindering our understanding of the methane cycle. This study quantifies how uncertainties in the hydroxyl radical may influence methane abundance in the atmosphere based on the inter-model comparison of hydroxyl radical fields and model simulations of CH4 abundance with different hydroxyl radical scenarios during 2000–2016. We show that hydroxyl radical changes could contribute up to 54 % of model-simulated methane biases.
Marleen Braun, Jens-Uwe Grooß, Wolfgang Woiwode, Sören Johansson, Michael Höpfner, Felix Friedl-Vallon, Hermann Oelhaf, Peter Preusse, Jörn Ungermann, Björn-Martin Sinnhuber, Helmut Ziereis, and Peter Braesicke
Atmos. Chem. Phys., 19, 13681–13699, https://doi.org/10.5194/acp-19-13681-2019, https://doi.org/10.5194/acp-19-13681-2019, 2019
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We analyse nitrification of the LMS in the Arctic winter 2015–2016 based on GLORIA measurements. Vertical cross sections of HNO3 for several flights show complex fine–scale structures and enhanced values down to 9 km. The extent of overall nitrification is quantified based on HNO3–O3 correlations and reaches between 5 ppbv and 7 ppbv at potential temperature levels between 350 and 380 K. Further, we compare our result with the atmospheric model CLaMS.
Kévin Lamy, Thierry Portafaix, Béatrice Josse, Colette Brogniez, Sophie Godin-Beekmann, Hassan Bencherif, Laura Revell, Hideharu Akiyoshi, Slimane Bekki, Michaela I. Hegglin, Patrick Jöckel, Oliver Kirner, Ben Liley, Virginie Marecal, Olaf Morgenstern, Andrea Stenke, Guang Zeng, N. Luke Abraham, Alexander T. Archibald, Neil Butchart, Martyn P. Chipperfield, Glauco Di Genova, Makoto Deushi, Sandip S. Dhomse, Rong-Ming Hu, Douglas Kinnison, Michael Kotkamp, Richard McKenzie, Martine Michou, Fiona M. O'Connor, Luke D. Oman, Giovanni Pitari, David A. Plummer, John A. Pyle, Eugene Rozanov, David Saint-Martin, Kengo Sudo, Taichu Y. Tanaka, Daniele Visioni, and Kohei Yoshida
Atmos. Chem. Phys., 19, 10087–10110, https://doi.org/10.5194/acp-19-10087-2019, https://doi.org/10.5194/acp-19-10087-2019, 2019
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In this study, we simulate the ultraviolet radiation evolution during the 21st century on Earth's surface using the output from several numerical models which participated in the Chemistry-Climate Model Initiative. We present four possible futures which depend on greenhouse gases emissions. The role of ozone-depleting substances, greenhouse gases and aerosols are investigated. Our results emphasize the important role of aerosols for future ultraviolet radiation in the Northern Hemisphere.
David C. Wade, Nathan Luke Abraham, Alexander Farnsworth, Paul J. Valdes, Fran Bragg, and Alexander T. Archibald
Clim. Past, 15, 1463–1483, https://doi.org/10.5194/cp-15-1463-2019, https://doi.org/10.5194/cp-15-1463-2019, 2019
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The amount of O2 in the atmosphere may have varied from as little as 10 % to as much as 35 % during the last 541 Myr. These changes are large enough to have led to changes in atmospheric mass, which may alter the radiative budget of the atmosphere. We present the first fully 3-D numerical model simulations to investigate the climate impacts of changes in O2 during different climate states. We identify a complex new mechanism causing increases in surface temperature when O2 levels were higher.
Ewa M. Bednarz, Amanda C. Maycock, Peter Braesicke, Paul J. Telford, N. Luke Abraham, and John A. Pyle
Atmos. Chem. Phys., 19, 9833–9846, https://doi.org/10.5194/acp-19-9833-2019, https://doi.org/10.5194/acp-19-9833-2019, 2019
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The atmospheric response to the amplitude of 11-year solar cycle in UM-UKCA is separated into the contributions from changes in direct radiative heating and photolysis rates, and the results compared with a control case with both effects included. We find that while the tropical responses are largely additive, this is not necessarily the case in the high latitudes. We suggest that solar-induced changes in ozone are important for modulating the SH dynamical response to the 11-year solar cycle.
Nils König, Peter Braesicke, and Thomas von Clarmann
Atmos. Meas. Tech., 12, 4113–4129, https://doi.org/10.5194/amt-12-4113-2019, https://doi.org/10.5194/amt-12-4113-2019, 2019
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Inference of the tropopause from temperature profiles of finite vertical resolution entails an uncertainty of the tropopause altitude. We assess this effect by degrading the resolution of the sonde data. The tropopause altitude inferred from coarse grid profiles was found to be lower than that inferred from the original profiles for tropical and midlatitudinal radiosonde profiles. The mean displacement of the lapse rate tropopause inferred from a 3 km resolution profile is −400 m for Hilo.
Zainab Q. Hakim, Scott Archer-Nicholls, Gufran Beig, Gerd A. Folberth, Kengo Sudo, Nathan Luke Abraham, Sachin Ghude, Daven K. Henze, and Alexander T. Archibald
Atmos. Chem. Phys., 19, 6437–6458, https://doi.org/10.5194/acp-19-6437-2019, https://doi.org/10.5194/acp-19-6437-2019, 2019
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Surface ozone is an important air pollutant and recent work has calculated that large numbers of people die prematurely because of exposure to high levels of surface ozone in India. However, these calculations require model simulations of ozone as key inputs.
Here we perform the most thorough evaluation of global model surface ozone over India to date. These analyses of model simulations and observations highlight some successes and shortcomings and the need for further process-based studies.
Bärbel Vogel, Rolf Müller, Gebhard Günther, Reinhold Spang, Sreeharsha Hanumanthu, Dan Li, Martin Riese, and Gabriele P. Stiller
Atmos. Chem. Phys., 19, 6007–6034, https://doi.org/10.5194/acp-19-6007-2019, https://doi.org/10.5194/acp-19-6007-2019, 2019
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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.
Ewa M. Bednarz, Amanda C. Maycock, Paul J. Telford, Peter Braesicke, N. Luke Abraham, and John A. Pyle
Atmos. Chem. Phys., 19, 5209–5233, https://doi.org/10.5194/acp-19-5209-2019, https://doi.org/10.5194/acp-19-5209-2019, 2019
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Following model improvements, the atmospheric response to the 11-year solar cycle forcing simulated in the UM-UKCA chemistry–climate model is discussed for the first time. In contrast to most previous studies in the literature, we compare the results diagnosed using both a composite and a MLR methodology, and we show that apparently different signals can be diagnosed in the troposphere. In addition, we look at the role of internal atmospheric variability for the detection of the solar response.
Fraser Dennison, James Keeble, Olaf Morgenstern, Guang Zeng, N. Luke Abraham, and Xin Yang
Geosci. Model Dev., 12, 1227–1239, https://doi.org/10.5194/gmd-12-1227-2019, https://doi.org/10.5194/gmd-12-1227-2019, 2019
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Two developments are made to the United Kingdom Chemistry and Aerosols (UKCA) model to improve simulation of stratospheric ozone. The first is the addition of a solar cycle. The influence on ozone from the solar cycle is found to be 1–2 %, which is consistent with other studies. The second is to the heterogeneous chemistry, the most significant change being the addition of reactions involving bromine species. This was shown to reduce ozone biases relative to observations in most regions.
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, https://doi.org/10.5194/acp-19-3097-2019, https://doi.org/10.5194/acp-19-3097-2019, 2019
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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.
Winfried Hoke, Tina Swierczynski, Peter Braesicke, Karin Lochte, Len Shaffrey, Martin Drews, Hilppa Gregow, Ralf Ludwig, Jan Even Øie Nilsen, Elisa Palazzi, Gianmaria Sannino, Lars Henrik Smedsrud, and ECRA network
Adv. Geosci., 46, 1–10, https://doi.org/10.5194/adgeo-46-1-2019, https://doi.org/10.5194/adgeo-46-1-2019, 2019
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The European Climate Research Alliance is a bottom-up association of European research institutions helping to facilitate the development of climate change research, combining the capacities of national research institutions and inducing closer ties between existing national research initiatives, projects and infrastructures. This article briefly introduces the network's structure and organisation, as well as project management issues and prospects.
Ines Tritscher, Jens-Uwe Grooß, Reinhold Spang, Michael C. Pitts, Lamont R. Poole, Rolf Müller, and Martin Riese
Atmos. Chem. Phys., 19, 543–563, https://doi.org/10.5194/acp-19-543-2019, https://doi.org/10.5194/acp-19-543-2019, 2019
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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.
Johannes Eckstein, Roland Ruhnke, Stephan Pfahl, Emanuel Christner, Christopher Diekmann, Christoph Dyroff, Daniel Reinert, Daniel Rieger, Matthias Schneider, Jennifer Schröter, Andreas Zahn, and Peter Braesicke
Geosci. Model Dev., 11, 5113–5133, https://doi.org/10.5194/gmd-11-5113-2018, https://doi.org/10.5194/gmd-11-5113-2018, 2018
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We present ICON-ART-Iso, an extension to the global circulation model ICON, which allows for the simulation of the stable isotopologues of water. The main advantage over other isotope-enabled models is its flexible design with respect to the number of tracers simulated. We compare the results of several simulations to measurements of different scale. ICON-ART-Iso is able to reasonably reproduce the measurements. It is a promising tool to aid in the investigation of the atmospheric water cycle.
Samuel R. Hall, Kirk Ullmann, Michael J. Prather, Clare M. Flynn, Lee T. Murray, Arlene M. Fiore, Gustavo Correa, Sarah A. Strode, Stephen D. Steenrod, Jean-Francois Lamarque, Jonathan Guth, Béatrice Josse, Johannes Flemming, Vincent Huijnen, N. Luke Abraham, and Alex T. Archibald
Atmos. Chem. Phys., 18, 16809–16828, https://doi.org/10.5194/acp-18-16809-2018, https://doi.org/10.5194/acp-18-16809-2018, 2018
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Photolysis (J rates) initiates and drives atmospheric chemistry, and Js are perturbed by factors of 2 by clouds. The NASA Atmospheric Tomography (ATom) Mission provides the first comprehensive observations on how clouds perturb Js through the remote Pacific and Atlantic basins. We compare these cloud-perturbation J statistics with those from nine global chemistry models. While basic patterns agree, there is a large spread across models, and all lack some basic features of the observations.
Laura E. Revell, Andrea Stenke, Fiona Tummon, Aryeh Feinberg, Eugene Rozanov, Thomas Peter, N. Luke Abraham, Hideharu Akiyoshi, Alexander T. Archibald, Neal Butchart, Makoto Deushi, Patrick Jöckel, Douglas Kinnison, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke D. Oman, Giovanni Pitari, David A. Plummer, Robyn Schofield, Kane Stone, Simone Tilmes, Daniele Visioni, Yousuke Yamashita, and Guang Zeng
Atmos. Chem. Phys., 18, 16155–16172, https://doi.org/10.5194/acp-18-16155-2018, https://doi.org/10.5194/acp-18-16155-2018, 2018
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Global models such as those participating in the Chemistry-Climate Model Initiative (CCMI) consistently simulate biases in tropospheric ozone compared with observations. We performed an advanced statistical analysis with one of the CCMI models to understand the cause of the bias. We found that emissions of ozone precursor gases are the dominant driver of the bias, implying either that the emissions are too large, or that the way in which the model handles emissions needs to be improved.
Xue Wu, Sabine Griessbach, and Lars Hoffmann
Atmos. Chem. Phys., 18, 15859–15877, https://doi.org/10.5194/acp-18-15859-2018, https://doi.org/10.5194/acp-18-15859-2018, 2018
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Volcanic aerosol is an important source of sulfur for Antarctica, where local sources of sulfur are rare. Midlatitude and high-latitude volcanism can directly influence the aerosol budget of the polar stratosphere, but tropical volcanic eruptions can also enhance polar aerosols by transport. Our study investigates pathway and transport processes of volcanic aerosol from the tropics to the lower stratosphere over Antarctica by combining Lagrangian transport simulation and satellite observations.
Michael Höpfner, Terry Deshler, Michael Pitts, Lamont Poole, Reinhold Spang, Gabriele Stiller, and Thomas von Clarmann
Atmos. Meas. Tech., 11, 5901–5923, https://doi.org/10.5194/amt-11-5901-2018, https://doi.org/10.5194/amt-11-5901-2018, 2018
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Polar stratospheric clouds (PSC) have major relevance to the processes leading to polar ozone depletion. A good understanding of these particles is a prerequisite to predict their role in a changing climate. We present the first global set of PSC volume density profiles derived from the MIPAS satellite measurements covering the entire mission period between 2002 and 2012. A comparison to CALIOP lidar measurements is provided. The dataset can serve as a basis for evaluation of atmospheric models.
Jennifer Schröter, Daniel Rieger, Christian Stassen, Heike Vogel, Michael Weimer, Sven Werchner, Jochen Förstner, Florian Prill, Daniel Reinert, Günther Zängl, Marco Giorgetta, Roland Ruhnke, Bernhard Vogel, and Peter Braesicke
Geosci. Model Dev., 11, 4043–4068, https://doi.org/10.5194/gmd-11-4043-2018, https://doi.org/10.5194/gmd-11-4043-2018, 2018
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In this paper, we introduce the most up-to-date version of the flexible tracer framework for the ICOsahedral Nonhydrostatic model with
Aerosols and Reactive Trace gases (ICON-ART).
We performed multiple simulations using different ICON physics configurations for weather and climate with ART.
The flexible tracer framework within ICON-ART 2.1 suits the demands of a large variety of different applications ranging from numerical weather prediction to climate integrations.
Nathan Luke Abraham, Alexander T. Archibald, Paul Cresswell, Sam Cusworth, Mohit Dalvi, David Matthews, Steven Wardle, and Stuart Whitehouse
Geosci. Model Dev., 11, 3647–3657, https://doi.org/10.5194/gmd-11-3647-2018, https://doi.org/10.5194/gmd-11-3647-2018, 2018
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Using a virtual machine environment, a low-resolution configuration of the United Kingdom Chemistry and Aerosols (UKCA) composition-climate model has been developed. This configuration, while not suitable for long simulations, is an excellent test-bed for new model developments and can be used to train new users in how to use UKCA. This work was motivated by the desire to improve the usability of UKCA, and to encourage more users to become involved with the code development process.
Emre Esentürk, Nathan Luke Abraham, Scott Archer-Nicholls, Christina Mitsakou, Paul Griffiths, Alex Archibald, and John Pyle
Geosci. Model Dev., 11, 3089–3108, https://doi.org/10.5194/gmd-11-3089-2018, https://doi.org/10.5194/gmd-11-3089-2018, 2018
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An integral and expensive part of coupled climate model simulations is the gas-phase chemistry which gives rise to hundreds of coupled differential equations. We propose a method which improves the convergence and robustness properties of commonly used Newton–Raphson solvers. The method is flexible and can be appended to most algorithms. The approach can be useful for a broader community of computational scientists whose interests lie in solving systems with intensive interactive chemistry.
Farahnaz Khosrawi, Oliver Kirner, Gabriele Stiller, Michael Höpfner, Michelle L. Santee, Sylvia Kellmann, and Peter Braesicke
Atmos. Chem. Phys., 18, 8873–8892, https://doi.org/10.5194/acp-18-8873-2018, https://doi.org/10.5194/acp-18-8873-2018, 2018
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An extensive assessment of the performance of the chemistry–climate model EMAC is given for Arctic winters 2009/2010 and 2010/2011. The EMAC simulations are compared to satellite observations. The comparisons between EMAC simulations and satellite observations show that model and measurements compare well for these two Arctic winters. However, differences between model and observations are found that need improvements in the model in the future.
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, https://doi.org/10.5194/acp-18-8647-2018, https://doi.org/10.5194/acp-18-8647-2018, 2018
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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.
Sandip S. Dhomse, Douglas Kinnison, Martyn P. Chipperfield, Ross J. Salawitch, Irene Cionni, Michaela I. Hegglin, N. Luke Abraham, Hideharu Akiyoshi, Alex T. Archibald, Ewa M. Bednarz, Slimane Bekki, Peter Braesicke, Neal Butchart, Martin Dameris, Makoto Deushi, Stacey Frith, Steven C. Hardiman, Birgit Hassler, Larry W. Horowitz, Rong-Ming Hu, Patrick Jöckel, Beatrice Josse, Oliver Kirner, Stefanie Kremser, Ulrike Langematz, Jared Lewis, Marion Marchand, Meiyun Lin, Eva Mancini, Virginie Marécal, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke Oman, Giovanni Pitari, David A. Plummer, John A. Pyle, Laura E. Revell, Eugene Rozanov, Robyn Schofield, Andrea Stenke, Kane Stone, Kengo Sudo, Simone Tilmes, Daniele Visioni, Yousuke Yamashita, and Guang Zeng
Atmos. Chem. Phys., 18, 8409–8438, https://doi.org/10.5194/acp-18-8409-2018, https://doi.org/10.5194/acp-18-8409-2018, 2018
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We analyse simulations from the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion by anthropogenic chlorine and bromine. The simulations from 20 models project that global column ozone will return to 1980 values in 2047 (uncertainty range 2042–2052). Return dates in other regions vary depending on factors related to climate change and importance of chlorine and bromine. Column ozone in the tropics may continue to decline.
James Keeble, Hannah Brown, N. Luke Abraham, Neil R. P. Harris, and John A. Pyle
Atmos. Chem. Phys., 18, 7625–7637, https://doi.org/10.5194/acp-18-7625-2018, https://doi.org/10.5194/acp-18-7625-2018, 2018
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2017 marks the 30th anniversary of the Montreal Protocol, which was implemented to protect the stratospheric ozone layer from the harmful effects of synthetic ozone depleting substances. Since the late 1990s atmospheric concentrations of these species have begun to decline, and as a result ozone concentrations are expected to increase. In this study we use an ensemble of chemistry–climate simulations to investigate recent ozone trends and search for early signs of ozone recovery.
Valerio Ferracci, Ines Heimann, N. Luke Abraham, John A. Pyle, and Alexander T. Archibald
Atmos. Chem. Phys., 18, 7109–7129, https://doi.org/10.5194/acp-18-7109-2018, https://doi.org/10.5194/acp-18-7109-2018, 2018
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Hydroxyl radicals (OH) control the removal of species emitted in the atmosphere. Field campaigns reported a "missing" OH sink, not included in current atmospheric models. In this work a global model was used to establish the impact of additional OH sinks, based on both observations of the missing sink and newly discovered reactions of OH. Results show modest increases in global atmospheric lifetimes but pronounced regional effects on the abundance of some key species.
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, https://doi.org/10.5194/acp-18-5089-2018, https://doi.org/10.5194/acp-18-5089-2018, 2018
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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.
Neal Butchart, James A. Anstey, Kevin Hamilton, Scott Osprey, Charles McLandress, Andrew C. Bushell, Yoshio Kawatani, Young-Ha Kim, Francois Lott, John Scinocca, Timothy N. Stockdale, Martin Andrews, Omar Bellprat, Peter Braesicke, Chiara Cagnazzo, Chih-Chieh Chen, Hye-Yeong Chun, Mikhail Dobrynin, Rolando R. Garcia, Javier Garcia-Serrano, Lesley J. Gray, Laura Holt, Tobias Kerzenmacher, Hiroaki Naoe, Holger Pohlmann, Jadwiga H. Richter, Adam A. Scaife, Verena Schenzinger, Federico Serva, Stefan Versick, Shingo Watanabe, Kohei Yoshida, and Seiji Yukimoto
Geosci. Model Dev., 11, 1009–1032, https://doi.org/10.5194/gmd-11-1009-2018, https://doi.org/10.5194/gmd-11-1009-2018, 2018
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This paper documents the numerical experiments to be used in phase 1 of the Stratosphere–troposphere Processes And their Role in Climate (SPARC) Quasi-Biennial Oscillation initiative (QBOi), which was set up to improve the representation of the QBO and tropical stratospheric variability in global climate models.
Thomas Rößler, Olaf Stein, Yi Heng, Paul Baumeister, and Lars Hoffmann
Geosci. Model Dev., 11, 575–592, https://doi.org/10.5194/gmd-11-575-2018, https://doi.org/10.5194/gmd-11-575-2018, 2018
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In this study, we performed an assessment of truncation errors and computational efficiency of trajectory calculations using six popular numerical integration schemes of the Runge–Kutta family. More than 5000 transport simulations for different seasons and regions of the free troposphere and stratosphere were conducted, driven by the latest version of ECMWF operational analyses and forecasts. The study provides guidelines to achieve the most accurate and efficient trajectory calculations.
Catrin I. Meyer, Manfred Ern, Lars Hoffmann, Quang Thai Trinh, and M. Joan Alexander
Atmos. Meas. Tech., 11, 215–232, https://doi.org/10.5194/amt-11-215-2018, https://doi.org/10.5194/amt-11-215-2018, 2018
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We investigate stratospheric gravity wave observations by the Atmospheric InfraRed Sounder (AIRS) and the High Resolution Dynamics Limb Sounder (HIRDLS). Waves seen by AIRS contribute significantly to momentum flux, which indicates a calculated momentum flux factor. AIRS and HIRDLS agree well in the phase structure of the wave events and also in the seasonal and latitudinal patterns of gravity wave activity and can be used complementary to each other.
James Keeble, Ewa M. Bednarz, Antara Banerjee, N. Luke Abraham, Neil R. P. Harris, Amanda C. Maycock, and John A. Pyle
Atmos. Chem. Phys., 17, 13801–13818, https://doi.org/10.5194/acp-17-13801-2017, https://doi.org/10.5194/acp-17-13801-2017, 2017
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In this study we explore the chemical and transport processes controlling ozone abundances in different altitude regions in the tropics for the present day and how these processes may change in the future in order to determine when total-column ozone values in the tropics will recover to pre-1980s values following the implementation of the Montreal Protocol and its subsequent amendments, which imposed bans on the use and emissions of CFCs.
Xue Wu, Sabine Griessbach, and Lars Hoffmann
Atmos. Chem. Phys., 17, 13439–13455, https://doi.org/10.5194/acp-17-13439-2017, https://doi.org/10.5194/acp-17-13439-2017, 2017
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This study is focused on the Sarychev eruption in 2009. Based on Lagrangian model simulations and satellite data, the equatorward transport of the plume and aerosol from the Sarychev eruption is confirmed, and the transport is facilitated by the Asian summer monsoon anticyclonic circulations. The aerosol transported to the tropics remained for months and dispersed upward, which could make the Sarychev eruption have a similar global climate impact as a tropical volcanic eruption.
Farahnaz Khosrawi, Oliver Kirner, Björn-Martin Sinnhuber, Sören Johansson, Michael Höpfner, Michelle L. Santee, Lucien Froidevaux, Jörn Ungermann, Roland Ruhnke, Wolfgang Woiwode, Hermann Oelhaf, and Peter Braesicke
Atmos. Chem. Phys., 17, 12893–12910, https://doi.org/10.5194/acp-17-12893-2017, https://doi.org/10.5194/acp-17-12893-2017, 2017
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The 2015/2016 Arctic winter was one of the coldest winters in recent years, allowing extensive PSC formation and chlorine activation. Model simulations of the 2015/2016 Arctic winter were performed with the atmospheric chemistry–climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC). We find that ozone loss was quite strong but not as strong as in 2010/2011; denitrification and dehydration were so far the strongest observed in the Arctic stratosphere in at least the past 10 years.
Corwin J. Wright, Neil P. Hindley, Lars Hoffmann, M. Joan Alexander, and Nicholas J. Mitchell
Atmos. Chem. Phys., 17, 8553–8575, https://doi.org/10.5194/acp-17-8553-2017, https://doi.org/10.5194/acp-17-8553-2017, 2017
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We introduce a novel 3-D method of measuring atmospheric gravity waves, based around a 3-D Stockwell transform. Our method lets us measure new properties, including wave intrinsic frequencies and phase and group velocities. We apply it to data from the AIRS satellite instrument over the Southern Andes for two consecutive winters. Our results show clear evidence that the waves measured are primarily orographic in origin, and that their group velocity vectors are focused into the polar night jet.
Lars Hoffmann, Albert Hertzog, Thomas Rößler, Olaf Stein, and Xue Wu
Atmos. Chem. Phys., 17, 8045–8061, https://doi.org/10.5194/acp-17-8045-2017, https://doi.org/10.5194/acp-17-8045-2017, 2017
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We present an intercomparison of temperatures and horizontal winds of five meteorological data sets (ECMWF operational analysis, ERA-Interim, MERRA, MERRA-2, and NCEP/NCAR) in the Antarctic lower stratosphere. The assessment is based on 19 superpressure balloon flights during the Concordiasi field campaign in September 2010 to January 2011. The balloon data are used to successfully validate trajectory calculations with the new Lagrangian particle dispersion model MPTRAC.
Michael Weimer, Jennifer Schröter, Johannes Eckstein, Konrad Deetz, Marco Neumaier, Garlich Fischbeck, Lu Hu, Dylan B. Millet, Daniel Rieger, Heike Vogel, Bernhard Vogel, Thomas Reddmann, Oliver Kirner, Roland Ruhnke, and Peter Braesicke
Geosci. Model Dev., 10, 2471–2494, https://doi.org/10.5194/gmd-10-2471-2017, https://doi.org/10.5194/gmd-10-2471-2017, 2017
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In this paper, the recently developed module for trace gas emissions in the online coupled modelling framework ICON-ART for atmospheric chemistry is presented. Algorithms for offline and online calculation of the emissions are described. The module is validated with ground-based as well as airborne measurements of acetone. It is shown that the module performs well and allows the simulation of annual cycles of emission-driven trace gases.
Lars Hoffmann, Reinhold Spang, Andrew Orr, M. Joan Alexander, Laura A. Holt, and Olaf Stein
Atmos. Chem. Phys., 17, 2901–2920, https://doi.org/10.5194/acp-17-2901-2017, https://doi.org/10.5194/acp-17-2901-2017, 2017
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We introduce a 10-year record (2003–2012) of AIRS/Aqua observations of gravity waves in the polar lower stratosphere. The data set was optimized to study the impact of gravity waves on the formation of polar stratospheric clouds (PSCs). We discuss the temporal and spatial patterns of gravity wave activity, validate explicitly resolved small-scale temperature fluctuations in the ECMWF data, and present a survey of gravity-wave-induced PSC formation events using joint AIRS and MIPAS observations.
Johannes Eckstein, Roland Ruhnke, Andreas Zahn, Marco Neumaier, Ole Kirner, and Peter Braesicke
Atmos. Chem. Phys., 17, 2775–2794, https://doi.org/10.5194/acp-17-2775-2017, https://doi.org/10.5194/acp-17-2775-2017, 2017
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Data on atmospheric trace gases have been collected with instruments on-board a commercial airliner for more than 10 years in the CARIBIC project. We investigate which species in the dataset can be used for a representative climatology, by comparing data from the chemistry–climate model EMAC along the flight paths to a larger set of model data. We find that long-lived species are captured quite well by the CARIBIC sample while this is not the case for more variable, shorter-lived species.
Olaf Morgenstern, Michaela I. Hegglin, Eugene Rozanov, Fiona M. O'Connor, N. Luke Abraham, Hideharu Akiyoshi, Alexander T. Archibald, Slimane Bekki, Neal Butchart, Martyn P. Chipperfield, Makoto Deushi, Sandip S. Dhomse, Rolando R. Garcia, Steven C. Hardiman, Larry W. Horowitz, Patrick Jöckel, Beatrice Josse, Douglas Kinnison, Meiyun Lin, Eva Mancini, Michael E. Manyin, Marion Marchand, Virginie Marécal, Martine Michou, Luke D. Oman, Giovanni Pitari, David A. Plummer, Laura E. Revell, David Saint-Martin, Robyn Schofield, Andrea Stenke, Kane Stone, Kengo Sudo, Taichu Y. Tanaka, Simone Tilmes, Yousuke Yamashita, Kohei Yoshida, and Guang Zeng
Geosci. Model Dev., 10, 639–671, https://doi.org/10.5194/gmd-10-639-2017, https://doi.org/10.5194/gmd-10-639-2017, 2017
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We present a review of the make-up of 20 models participating in the Chemistry–Climate Model Initiative (CCMI). In comparison to earlier such activities, most of these models comprise a whole-atmosphere chemistry, and several of them include an interactive ocean module. This makes them suitable for studying the interactions of tropospheric air quality, stratospheric ozone, and climate. The paper lays the foundation for other studies using the CCMI simulations for scientific analysis.
Ulrike Langematz, Franziska Schmidt, Markus Kunze, Gregory E. Bodeker, and Peter Braesicke
Atmos. Chem. Phys., 16, 15619–15627, https://doi.org/10.5194/acp-16-15619-2016, https://doi.org/10.5194/acp-16-15619-2016, 2016
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The extent of anthropogenically driven Antarctic ozone depletion prior to 1980 is examined using transient chemistry–climate model simulations from 1960 to 2000 with prescribed changes of ozone depleting substances in conjunction with observations. All models show a long-term, halogen-induced negative trend in Antarctic ozone from 1960 to 1980, ranging between 26 and 50 % of the total anthropogenic ozone depletion from 1960 to 2000. A stronger ozone decline of 56 % was estimated from observation.
Mingjin Tang, James Keeble, Paul J. Telford, Francis D. Pope, Peter Braesicke, Paul T. Griffiths, N. Luke Abraham, James McGregor, I. Matt Watson, R. Anthony Cox, John A. Pyle, and Markus Kalberer
Atmos. Chem. Phys., 16, 15397–15412, https://doi.org/10.5194/acp-16-15397-2016, https://doi.org/10.5194/acp-16-15397-2016, 2016
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We have investigated for the first time the heterogeneous hydrolysis of ClONO2 on TiO2 and SiO2 aerosol particles at room temperature and at different relative humidities (RHs), using an aerosol flow tube. The kinetic data reported in our current and previous studies have been included in the UKCA chemistry–climate model to assess the impact of TiO2 injection on stratospheric chemistry and stratospheric ozone in particular.
Ewa M. Bednarz, Amanda C. Maycock, N. Luke Abraham, Peter Braesicke, Olivier Dessens, and John A. Pyle
Atmos. Chem. Phys., 16, 12159–12176, https://doi.org/10.5194/acp-16-12159-2016, https://doi.org/10.5194/acp-16-12159-2016, 2016
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Future trends in springtime Arctic ozone, and its chemical dynamical and radiative drivers, are analysed using a 7-member ensemble of chemistry–climate model integrations, allowing for a detailed assessment of interannual variability. Despite the future long-term recovery of Arctic ozone, there is large interannual variability and episodic reductions in springtime Arctic column ozone. Halogen chemistry will become a smaller but non-negligible driver of Arctic ozone variability over the century.
Sabine Griessbach, Lars Hoffmann, Reinhold Spang, Marc von Hobe, Rolf Müller, and Martin Riese
Atmos. Meas. Tech., 9, 4399–4423, https://doi.org/10.5194/amt-9-4399-2016, https://doi.org/10.5194/amt-9-4399-2016, 2016
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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, https://doi.org/10.5194/amt-9-3619-2016, https://doi.org/10.5194/amt-9-3619-2016, 2016
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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.
Wolfgang Woiwode, Michael Höpfner, Lei Bi, Michael C. Pitts, Lamont R. Poole, Hermann Oelhaf, Sergej Molleker, Stephan Borrmann, Marcus Klingebiel, Gennady Belyaev, Andreas Ebersoldt, Sabine Griessbach, Jens-Uwe Grooß, Thomas Gulde, Martina Krämer, Guido Maucher, Christof Piesch, Christian Rolf, Christian Sartorius, Reinhold Spang, and Johannes Orphal
Atmos. Chem. Phys., 16, 9505–9532, https://doi.org/10.5194/acp-16-9505-2016, https://doi.org/10.5194/acp-16-9505-2016, 2016
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The analysis of spectral signatures of a polar stratospheric cloud in airborne infrared remote sensing observations in the Arctic in combination with further collocated measurements supports the view that the observed cloud consisted of highly aspherical nitric acid trihydrate particles. A characteristic "shoulder-like" spectral signature may be exploited for identification of large, highly aspherical nitric acid trihydrate particles involved in denitrification of the polar winter stratosphere.
Lars Hoffmann, Alison W. Grimsdell, and M. Joan Alexander
Atmos. Chem. Phys., 16, 9381–9397, https://doi.org/10.5194/acp-16-9381-2016, https://doi.org/10.5194/acp-16-9381-2016, 2016
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We present a 12-year record (2003-2014) of stratospheric gravity wave activity at Southern Hemisphere orographic hotspots as observed by the AIRS/Aqua satellite instrument. We introduce a method to discriminate between gravity waves from orographic or other sources and propose a simple model to predict the occurrence of mountain waves using zonal wind thresholds. The prediction model can help to disentangle upper level wind effects from low level source and other influences.
R. Hossaini, P. K. Patra, A. A. Leeson, G. Krysztofiak, N. L. Abraham, S. J. Andrews, A. T. Archibald, J. Aschmann, E. L. Atlas, D. A. Belikov, H. Bönisch, L. J. Carpenter, S. Dhomse, M. Dorf, A. Engel, W. Feng, S. Fuhlbrügge, P. T. Griffiths, N. R. P. Harris, R. Hommel, T. Keber, K. Krüger, S. T. Lennartz, S. Maksyutov, H. Mantle, G. P. Mills, B. Miller, S. A. Montzka, F. Moore, M. A. Navarro, D. E. Oram, K. Pfeilsticker, J. A. Pyle, B. Quack, A. D. Robinson, E. Saikawa, A. Saiz-Lopez, S. Sala, B.-M. Sinnhuber, S. Taguchi, S. Tegtmeier, R. T. Lidster, C. Wilson, and F. Ziska
Atmos. Chem. Phys., 16, 9163–9187, https://doi.org/10.5194/acp-16-9163-2016, https://doi.org/10.5194/acp-16-9163-2016, 2016
David A. Newnham, George P. Ford, Tracy Moffat-Griffin, and Hugh C. Pumphrey
Atmos. Meas. Tech., 9, 3309–3323, https://doi.org/10.5194/amt-9-3309-2016, https://doi.org/10.5194/amt-9-3309-2016, 2016
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We demonstrate the feasibility of measuring polar atmospheric winds over the altitude range 23–97 km using ground-based millimetre-wave Doppler radiometry. Atmospheric and instrument simulations were carried out for Halley station, Antarctica. This remote sensing technique will provide continuous horizontal wind observations in the stratosphere and mesosphere where measurements are currently very limited. The data are needed for meteorological analyses and atmospheric modelling applications.
Markus Kunze, Peter Braesicke, Ulrike Langematz, and Gabriele Stiller
Atmos. Chem. Phys., 16, 8695–8714, https://doi.org/10.5194/acp-16-8695-2016, https://doi.org/10.5194/acp-16-8695-2016, 2016
Khalil Karami, Peter Braesicke, Miriam Sinnhuber, and Stefan Versick
Atmos. Chem. Phys., 16, 8447–8460, https://doi.org/10.5194/acp-16-8447-2016, https://doi.org/10.5194/acp-16-8447-2016, 2016
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We introduce a diagnostic tool to assess in a climatological framework the optimal propagation conditions for stationary planetary waves. Analyzing 50 winters using NCEP/NCAR reanalysis data we demonstrate several problematic features of the refractive index of Rossby waves. We introduced the Rossby waves membership value function to calculate the optimal propagation conditions for Rossby waves. Sensitivity of our diagnostic tool to strong and weak vortex regimes are examined.
Jörn Ungermann, Mandfred Ern, Martin Kaufmann, Rolf Müller, Reinhold Spang, Felix Ploeger, Bärbel Vogel, and Martin Riese
Atmos. Chem. Phys., 16, 8389–8403, https://doi.org/10.5194/acp-16-8389-2016, https://doi.org/10.5194/acp-16-8389-2016, 2016
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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.
Yi Heng, Lars Hoffmann, Sabine Griessbach, Thomas Rößler, and Olaf Stein
Geosci. Model Dev., 9, 1627–1645, https://doi.org/10.5194/gmd-9-1627-2016, https://doi.org/10.5194/gmd-9-1627-2016, 2016
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A new inverse modeling and simulation system is developed to enable efficient and reliable transport simulations of volcanic SO2 at large scale. The complex time- and altitude-dependent volcanic emission pattern of the Nabro eruption is identified by our inversion algorithm. The simulation results show good agreements with different satellite observations in terms of SO2 horizontal distributions, and help to further reveal the complex transport processes such as the Asian monsoon circulation.
Peer Johannes Nowack, Nathan Luke Abraham, Peter Braesicke, and John Adrian Pyle
Atmos. Chem. Phys., 16, 4191–4203, https://doi.org/10.5194/acp-16-4191-2016, https://doi.org/10.5194/acp-16-4191-2016, 2016
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Various forms of solar radiation management (SRM) have been proposed to counteract man-made climate change. However, all these countermeasures could have unintended side-effects. We add a novel perspective to this discussion by showing how atmospheric ozone changes under solar geoengineering could affect UV exposure and air pollution. This would have implications for human health and ecology. Atmospheric composition changes are therefore important to consider in the evaluation of any SRM scheme.
Antara Banerjee, Amanda C. Maycock, Alexander T. Archibald, N. Luke Abraham, Paul Telford, Peter Braesicke, and John A. Pyle
Atmos. Chem. Phys., 16, 2727–2746, https://doi.org/10.5194/acp-16-2727-2016, https://doi.org/10.5194/acp-16-2727-2016, 2016
F. Khosrawi, J. Urban, S. Lossow, G. Stiller, K. Weigel, P. Braesicke, M. C. Pitts, A. Rozanov, J. P. Burrows, and D. Murtagh
Atmos. Chem. Phys., 16, 101–121, https://doi.org/10.5194/acp-16-101-2016, https://doi.org/10.5194/acp-16-101-2016, 2016
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Our sensitivity studies based on air parcel trajectories confirm that Polar stratospheric cloud (PSC) formation is quite sensitive to water vapour and temperature changes. Considering water vapour time series from satellite measurements we do not find a consistent, significant trend in water vapour in the lower stratosphere during the past 15 years (2000–2014). Thus, the severe dentrification observed in 2010/2011 cannot be directly related to increases in stratospheric water vapour.
K. Karami, P. Braesicke, M. Kunze, U. Langematz, M. Sinnhuber, and S. Versick
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-15-33283-2015, https://doi.org/10.5194/acpd-15-33283-2015, 2015
Revised manuscript has not been submitted
A. Orr, J. S. Hosking, L. Hoffmann, J. Keeble, S. M. Dean, H. K. Roscoe, N. L. Abraham, S. Vosper, and P. Braesicke
Atmos. Chem. Phys., 15, 1071–1086, https://doi.org/10.5194/acp-15-1071-2015, https://doi.org/10.5194/acp-15-1071-2015, 2015
R. Spang, G. Günther, M. Riese, L. Hoffmann, R. Müller, and S. Griessbach
Atmos. Chem. Phys., 15, 927–950, https://doi.org/10.5194/acp-15-927-2015, https://doi.org/10.5194/acp-15-927-2015, 2015
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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.
J. Keeble, P. Braesicke, N. L. Abraham, H. K. Roscoe, and J. A. Pyle
Atmos. Chem. Phys., 14, 13705–13717, https://doi.org/10.5194/acp-14-13705-2014, https://doi.org/10.5194/acp-14-13705-2014, 2014
L. Hoffmann, M. J. Alexander, C. Clerbaux, A. W. Grimsdell, C. I. Meyer, T. Rößler, and B. Tournier
Atmos. Meas. Tech., 7, 4517–4537, https://doi.org/10.5194/amt-7-4517-2014, https://doi.org/10.5194/amt-7-4517-2014, 2014
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We present stratospheric gravity wave observations from 4.3 micron radiance measurements by the nadir sounders AIRS and IASI. Three case studies demonstrate that AIRS and IASI provide a consistent picture of the temporal development of individual gravity wave events. Statistical comparisons based on five years of data (2008-2012) also showed similar patterns of gravity wave activity. Long-term records from combined satellite data are an exciting prospect for future gravity wave research.
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, https://doi.org/10.5194/gmd-7-2895-2014, https://doi.org/10.5194/gmd-7-2895-2014, 2014
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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.
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, https://doi.org/10.5194/acp-14-12479-2014, https://doi.org/10.5194/acp-14-12479-2014, 2014
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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, https://doi.org/10.5194/gmd-7-2639-2014, https://doi.org/10.5194/gmd-7-2639-2014, 2014
S. S. Dhomse, K. M. Emmerson, G. W. Mann, N. Bellouin, K. S. Carslaw, M. P. Chipperfield, R. Hommel, N. L. Abraham, P. Telford, P. Braesicke, M. Dalvi, C. E. Johnson, F. O'Connor, O. Morgenstern, J. A. Pyle, T. Deshler, J. M. Zawodny, and L. W. Thomason
Atmos. Chem. Phys., 14, 11221–11246, https://doi.org/10.5194/acp-14-11221-2014, https://doi.org/10.5194/acp-14-11221-2014, 2014
X. Yang, N. L. Abraham, A. T. Archibald, P. Braesicke, J. Keeble, P. J. Telford, N. J. Warwick, and J. A. Pyle
Atmos. Chem. Phys., 14, 10431–10438, https://doi.org/10.5194/acp-14-10431-2014, https://doi.org/10.5194/acp-14-10431-2014, 2014
A. Banerjee, A. T. Archibald, A. C. Maycock, P. Telford, N. L. Abraham, X. Yang, P. Braesicke, and J. A. Pyle
Atmos. Chem. Phys., 14, 9871–9881, https://doi.org/10.5194/acp-14-9871-2014, https://doi.org/10.5194/acp-14-9871-2014, 2014
M. Riese, H. Oelhaf, P. Preusse, J. Blank, M. Ern, F. Friedl-Vallon, H. Fischer, T. Guggenmoser, M. Höpfner, P. Hoor, M. Kaufmann, J. Orphal, F. Plöger, R. Spang, O. Suminska-Ebersoldt, J. Ungermann, B. Vogel, and W. Woiwode
Atmos. Meas. Tech., 7, 1915–1928, https://doi.org/10.5194/amt-7-1915-2014, https://doi.org/10.5194/amt-7-1915-2014, 2014
M. J. Tang, P. J. Telford, F. D. Pope, L. Rkiouak, N. L. Abraham, A. T. Archibald, P. Braesicke, J. A. Pyle, J. McGregor, I. M. Watson, R. A. Cox, and M. Kalberer
Atmos. Chem. Phys., 14, 6035–6048, https://doi.org/10.5194/acp-14-6035-2014, https://doi.org/10.5194/acp-14-6035-2014, 2014
S. Griessbach, L. Hoffmann, R. Spang, and M. Riese
Atmos. Meas. Tech., 7, 1487–1507, https://doi.org/10.5194/amt-7-1487-2014, https://doi.org/10.5194/amt-7-1487-2014, 2014
F. M. O'Connor, C. E. Johnson, O. Morgenstern, N. L. Abraham, P. Braesicke, M. Dalvi, G. A. Folberth, M. G. Sanderson, P. J. Telford, A. Voulgarakis, P. J. Young, G. Zeng, W. J. Collins, and J. A. Pyle
Geosci. Model Dev., 7, 41–91, https://doi.org/10.5194/gmd-7-41-2014, https://doi.org/10.5194/gmd-7-41-2014, 2014
C. Kalicinsky, J.-U. Grooß, G. Günther, J. Ungermann, J. Blank, S. Höfer, L. Hoffmann, P. Knieling, F. Olschewski, R. Spang, F. Stroh, and M. Riese
Atmos. Chem. Phys., 13, 10859–10871, https://doi.org/10.5194/acp-13-10859-2013, https://doi.org/10.5194/acp-13-10859-2013, 2013
P. Braesicke, J. Keeble, X. Yang, G. Stiller, S. Kellmann, N. L. Abraham, A. Archibald, P. Telford, and J. A. Pyle
Atmos. Chem. Phys., 13, 10677–10688, https://doi.org/10.5194/acp-13-10677-2013, https://doi.org/10.5194/acp-13-10677-2013, 2013
J. Ungermann, L. L. Pan, C. Kalicinsky, F. Olschewski, P. Knieling, J. Blank, K. Weigel, T. Guggenmoser, F. Stroh, L. Hoffmann, and M. Riese
Atmos. Chem. Phys., 13, 10517–10534, https://doi.org/10.5194/acp-13-10517-2013, https://doi.org/10.5194/acp-13-10517-2013, 2013
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, https://doi.org/10.5194/acp-13-9233-2013, https://doi.org/10.5194/acp-13-9233-2013, 2013
K. Minschwaner, L. Hoffmann, A. Brown, M. Riese, R. Müller, and P. F. Bernath
Atmos. Chem. Phys., 13, 4253–4263, https://doi.org/10.5194/acp-13-4253-2013, https://doi.org/10.5194/acp-13-4253-2013, 2013
P. J. Telford, N. L. Abraham, A. T. Archibald, P. Braesicke, M. Dalvi, O. Morgenstern, F. M. O'Connor, N. A. D. Richards, and J. A. Pyle
Geosci. Model Dev., 6, 161–177, https://doi.org/10.5194/gmd-6-161-2013, https://doi.org/10.5194/gmd-6-161-2013, 2013
Related subject area
Subject: Dynamics | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Stratosphere | Science Focus: Physics (physical properties and processes)
Age of air from in situ trace gas measurements: insights from a new technique
Tropospheric links to uncertainty in stratospheric subseasonal predictions
The impact of El Niño–Southern Oscillation on the total column ozone over the Tibetan Plateau
Exploring ozone variability in the upper troposphere and lower stratosphere using dynamical coordinates
Climatology of the terms and variables of transformed Eulerian-mean (TEM) equations from multiple reanalyses: MERRA-2, JRA-55, ERA-Interim, and CFSR
Quasi-biennial oscillation modulation of stratospheric water vapour in the Asian monsoon
Crucial role of obliquely propagating gravity waves in the quasi-biennial oscillation dynamics
Technical note: Multi-year changes in the Brewer–Dobson circulation from Halogen Occultation Experiment (HALOE) methane
Exploring the ENSO modulation of the QBO periods with GISS E2.2 models
The impact of ENSO and NAO initial conditions and anomalies on the modeled response to Pinatubo-sized volcanic forcing
Stratospherically induced circulation changes under the extreme conditions of the no-Montreal-Protocol scenario
Vortex preconditioning of the 2021 sudden stratospheric warming: barotropic–baroclinic instability associated with the double westerly jets
On the pattern of interannual polar vortex–ozone co-variability during northern hemispheric winter
A mountain ridge model for quantifying oblique mountain wave propagation and distribution
Weakening of the tropical tropopause layer cold trap with global warming
On the magnitude and sensitivity of the quasi-biennial oscillation response to a tropical volcanic eruption
The response of the North Pacific jet and stratosphere-to-troposphere transport of ozone over western North America to RCP8.5 climate forcing
The Holton–Tan mechanism under stratospheric aerosol intervention
Very-long-period oscillations in the atmosphere (0–110 km) – Part 2: Latitude– longitude comparisons and trends
Driving mechanisms for the El Niño–Southern Oscillation impact on stratospheric ozone
Exploring the link between austral stratospheric polar vortex anomalies and surface climate in chemistry-climate models
The impact of improved spatial and temporal resolution of reanalysis data on Lagrangian studies of the tropical tropopause layer
Dynamics of ENSO-driven stratosphere-to-troposphere transport of ozone over North America
Ozone–gravity wave interaction in the upper stratosphere/lower mesosphere
How can Brewer–Dobson circulation trends be estimated from changes in stratospheric water vapour and methane?
The semi-annual oscillation (SAO) in the upper troposphere and lower stratosphere (UTLS)
Interactions between the stratospheric polar vortex and Atlantic circulation on seasonal to multi-decadal timescales
Impacts of three types of solar geoengineering on the Atlantic Meridional Overturning Circulation
Enhanced upward motion through the troposphere over the tropical western Pacific and its implications for the transport of trace gases from the troposphere to the stratosphere
Evolution of the intensity and duration of the Southern Hemisphere stratospheric polar vortex edge for the period 1979–2020
Characterization of transport from the Asian summer monsoon anticyclone into the UTLS via shedding of low potential vorticity cutoffs
Long-range prediction and the stratosphere
Weakening of Antarctic stratospheric planetary wave activities in early austral spring since the early 2000s: a response to sea surface temperature trends
The impact of sulfur hexafluoride (SF6) sinks on age of air climatologies and trends
Specified dynamics scheme impacts on wave-mean flow dynamics, convection, and tracer transport in CESM2 (WACCM6)
Propagation paths and source distributions of resolved gravity waves in ECMWF-IFS analysis fields around the southern polar night jet
Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003
Eastward-propagating planetary waves in the polar middle atmosphere
The Brewer–Dobson circulation in CMIP6
Climate impact of volcanic eruptions: the sensitivity to eruption season and latitude in MPI-ESM ensemble experiments
Contributions of equatorial waves and small-scale convective gravity waves to the 2019/20 quasi-biennial oscillation (QBO) disruption
Differences in the quasi-biennial oscillation response to stratospheric aerosol modification depending on injection strategy and species
The advective Brewer–Dobson circulation in the ERA5 reanalysis: climatology, variability, and trends
Is our dynamical understanding of the circulation changes associated with the Antarctic ozone hole sensitive to the choice of reanalysis dataset?
The impact of increasing stratospheric radiative damping on the quasi-biennial oscillation period
Analysis of recent lower-stratospheric ozone trends in chemistry climate models
Asymmetry and pathways of inter-hemispheric transport in the upper troposphere and lower stratosphere
Effects of prescribed CMIP6 ozone on simulating the Southern Hemisphere atmospheric circulation response to ozone depletion
Reanalysis intercomparison of potential vorticity and potential-vorticity-based diagnostics
Influence of the El Niño–Southern Oscillation on entry stratospheric water vapor in coupled chemistry–ocean CCMI and CMIP6 models
Eric A. Ray, Fred L. Moore, Hella Garny, Eric J. Hintsa, Bradley D. Hall, Geoff S. Dutton, David Nance, James W. Elkins, Steven C. Wofsy, Jasna Pittman, Bruce Daube, Bianca C. Baier, Jianghanyang Li, and Colm Sweeney
Atmos. Chem. Phys., 24, 12425–12445, https://doi.org/10.5194/acp-24-12425-2024, https://doi.org/10.5194/acp-24-12425-2024, 2024
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In this study we describe new techniques to derive age of air from multiple simultaneous measurements of long-lived trace gases in order to improve the fidelity of the age-of-air estimates and to be able to compare age of air from measurements taken from different instruments, platforms and decades. This technique also allows new transport information to be obtained from the measurements such as the primary source latitude that can also be compared to models.
Rachel W.-Y. Wu, Gabriel Chiodo, Inna Polichtchouk, and Daniela I. V. Domeisen
Atmos. Chem. Phys., 24, 12259–12275, https://doi.org/10.5194/acp-24-12259-2024, https://doi.org/10.5194/acp-24-12259-2024, 2024
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Strong variations in the strength of the stratospheric polar vortex can profoundly affect surface weather extremes; therefore, accurately predicting the stratosphere can improve surface weather forecasts. The research reveals how uncertainty in the stratosphere is linked to the troposphere. The findings suggest that refining models to better represent the identified sources and impact regions in the troposphere is likely to improve the prediction of the stratosphere and its surface impacts.
Yang Li, Wuhu Feng, Xin Zhou, Yajuan Li, and Martyn P. Chipperfield
Atmos. Chem. Phys., 24, 8277–8293, https://doi.org/10.5194/acp-24-8277-2024, https://doi.org/10.5194/acp-24-8277-2024, 2024
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The Tibetan Plateau (TP), the highest and largest plateau, experiences strong surface solar UV radiation, whose excess can cause harmful influences on local biota. Hence, it is critical to study TP ozone. We find ENSO, the strongest interannual phenomenon, tends to induce tropospheric temperature change and thus modulate tropopause variability, which in turn favours ozone change over the TP. Our results have implications for a better understanding of the interannual variability of TP ozone.
Luis F. Millán, Peter Hoor, Michaela I. Hegglin, Gloria L. Manney, Harald Boenisch, Paul Jeffery, Daniel Kunkel, Irina Petropavlovskikh, Hao Ye, Thierry Leblanc, and Kaley Walker
Atmos. Chem. Phys., 24, 7927–7959, https://doi.org/10.5194/acp-24-7927-2024, https://doi.org/10.5194/acp-24-7927-2024, 2024
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In the Observed Composition Trends And Variability in the UTLS (OCTAV-UTLS) Stratosphere-troposphere Processes And their Role in Climate (SPARC) activity, we have mapped multiplatform ozone datasets into coordinate systems to systematically evaluate the influence of these coordinates on binned climatological variability. This effort unifies the work of studies that focused on individual coordinate system variability. Our goal was to create the most comprehensive assessment of this topic.
Masatomo Fujiwara, Patrick Martineau, Jonathon S. Wright, Marta Abalos, Petr Šácha, Yoshio Kawatani, Sean M. Davis, Thomas Birner, and Beatriz M. Monge-Sanz
Atmos. Chem. Phys., 24, 7873–7898, https://doi.org/10.5194/acp-24-7873-2024, https://doi.org/10.5194/acp-24-7873-2024, 2024
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A climatology of the major variables and terms of the transformed Eulerian-mean (TEM) momentum and thermodynamic equations from four global atmospheric reanalyses is evaluated. The spread among reanalysis TEM momentum balance terms is around 10 % in Northern Hemisphere winter and up to 50 % in Southern Hemisphere winter. The largest uncertainties in the thermodynamic equation (about 50 %) are in the vertical advection, which does not show a structure consistent with the differences in heating.
Cristina Peña-Ortiz, Nuria Pilar Plaza, David Gallego, and Felix Ploeger
Atmos. Chem. Phys., 24, 5457–5478, https://doi.org/10.5194/acp-24-5457-2024, https://doi.org/10.5194/acp-24-5457-2024, 2024
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Although water vapour (H2O) in the lower stratosphere is only a few molecules among 1 million air molecules, atmospheric radiative forcing and surface temperature are sensitive to changes in its concentration. Monsoon regions play a key role in H2O transport and its concentration in the lower stratosphere. We show how the quasi-biennial oscillation (QBO) has a major impact on H2O over the Asian monsoon during August through changes in temperature caused by QBO modulation of tropical clouds.
Young-Ha Kim, Georg Sebastian Voelker, Gergely Bölöni, Günther Zängl, and Ulrich Achatz
Atmos. Chem. Phys., 24, 3297–3308, https://doi.org/10.5194/acp-24-3297-2024, https://doi.org/10.5194/acp-24-3297-2024, 2024
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The quasi-biennial oscillation, which governs the tropical stratospheric circulation, is driven primarily by small-scale wave processes. We employ a novel method to realistically represent these wave processes in a global model, thereby revealing an aspect of the oscillation that has not been identified before. We find that the oblique propagation of waves, a process neglected by existing climate models, plays a pivotal role in the stratospheric circulation and its oscillation.
Ellis Remsberg
Atmos. Chem. Phys., 24, 1691–1697, https://doi.org/10.5194/acp-24-1691-2024, https://doi.org/10.5194/acp-24-1691-2024, 2024
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CH4 data from the Halogen Occultation Experiment show clear changes in the deep and shallow branches of the Brewer–Dobson circulation (BDC) from 1992 to 2005. CH4 decreased in the upper stratosphere in the early 1990s following the Pinatubo eruption. There was also meridional transport of CH4 from the tropics to mid-latitudes in both hemispheres in the late 1990s. CH4 trends in the shallow branch agree with the tropospheric CH4 trends from 1996 to 2005.
Tiehan Zhou, Kevin J. DallaSanta, Clara Orbe, David H. Rind, Jeffrey A. Jonas, Larissa Nazarenko, Gavin A. Schmidt, and Gary Russell
Atmos. Chem. Phys., 24, 509–532, https://doi.org/10.5194/acp-24-509-2024, https://doi.org/10.5194/acp-24-509-2024, 2024
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The El Niño–Southern Oscillation (ENSO) tends to speed up and slow down the phase speed of the Quasi-Biennial Oscillation (QBO) during El Niño and La Niña, respectively. The ENSO modulation of the QBO does not show up in the climate models with parameterized but temporally constant gravity wave sources. We show that the GISS E2.2 models can capture the observed ENSO modulation of the QBO period with a horizontal resolution of 2° by 2.5° and its gravity wave sources parameterized interactively.
Helen Weierbach, Allegra N. LeGrande, and Kostas Tsigaridis
Atmos. Chem. Phys., 23, 15491–15505, https://doi.org/10.5194/acp-23-15491-2023, https://doi.org/10.5194/acp-23-15491-2023, 2023
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Volcanic aerosols impact global and regional climate conditions but can vary depending on pre-existing initial climate conditions. We ran an ensemble of volcanic aerosol simulations under varying ENSO and NAO initial conditions to understand how initial climate states impact the modeled response to volcanic forcing. Overall we found that initial NAO conditions can impact the strength of the first winter post-eruptive response but are also affected by the choice of anomaly and sampling routine.
Franziska Zilker, Timofei Sukhodolov, Gabriel Chiodo, Marina Friedel, Tatiana Egorova, Eugene Rozanov, Jan Sedlacek, Svenja Seeber, and Thomas Peter
Atmos. Chem. Phys., 23, 13387–13411, https://doi.org/10.5194/acp-23-13387-2023, https://doi.org/10.5194/acp-23-13387-2023, 2023
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The Montreal Protocol (MP) has successfully reduced the Antarctic ozone hole by banning chlorofluorocarbons (CFCs) that destroy the ozone layer. Moreover, CFCs are strong greenhouse gases (GHGs) that would have strengthened global warming. In this study, we investigate the surface weather and climate in a world without the MP at the end of the 21st century, disentangling ozone-mediated and GHG impacts of CFCs. Overall, we avoided 1.7 K global surface warming and a poleward shift in storm tracks.
Ji-Hee Yoo, Hye-Yeong Chun, and Min-Jee Kang
Atmos. Chem. Phys., 23, 10869–10881, https://doi.org/10.5194/acp-23-10869-2023, https://doi.org/10.5194/acp-23-10869-2023, 2023
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The January 2021 sudden stratospheric warming was preceded by unusual double westerly jets with polar stratospheric and subtropical mesospheric cores. This wind structure promotes anomalous dissipation of tropospheric planetary waves between the two maxima, leading to unusually strong shear instability. Shear instability generates the westward-propagating planetary waves with zonal wavenumber 2 in situ, thereby splitting the polar vortex just before the onset.
Frederik Harzer, Hella Garny, Felix Ploeger, Harald Bönisch, Peter Hoor, and Thomas Birner
Atmos. Chem. Phys., 23, 10661–10675, https://doi.org/10.5194/acp-23-10661-2023, https://doi.org/10.5194/acp-23-10661-2023, 2023
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We study the statistical relation between year-by-year fluctuations in winter-mean ozone and the strength of the stratospheric polar vortex. In the latitude–pressure plane, regression analysis shows that anomalously weak polar vortex years are associated with three pronounced local ozone maxima over the polar cap relative to the winter climatology. These response maxima primarily reflect the non-trivial combination of different ozone transport processes with varying relative contributions.
Sebastian Rhode, Peter Preusse, Manfred Ern, Jörn Ungermann, Lukas Krasauskas, Julio Bacmeister, and Martin Riese
Atmos. Chem. Phys., 23, 7901–7934, https://doi.org/10.5194/acp-23-7901-2023, https://doi.org/10.5194/acp-23-7901-2023, 2023
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Gravity waves (GWs) transport energy vertically and horizontally within the atmosphere and thereby affect wind speeds far from their sources. Here, we present a model that identifies orographic GW sources and predicts the pathways of the excited GWs through the atmosphere for a better understanding of horizontal GW propagation. We use this model to explain physical patterns in satellite observations (e.g., low GW activity above the Himalaya) and predict seasonal patterns of GW propagation.
Stephen Bourguet and Marianna Linz
Atmos. Chem. Phys., 23, 7447–7460, https://doi.org/10.5194/acp-23-7447-2023, https://doi.org/10.5194/acp-23-7447-2023, 2023
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Here, we show how projected changes to tropical circulation will impact the water vapor concentration in the lower stratosphere, which has implications for surface climate and stratospheric chemistry. In our transport scenarios with slower east–west winds, air parcels ascending into the stratosphere do not experience the same cold temperatures that they would today. This effect could act in concert with previously modeled changes to stratospheric water vapor to amplify surface warming.
Flossie Brown, Lauren Marshall, Peter H. Haynes, Rolando R. Garcia, Thomas Birner, and Anja Schmidt
Atmos. Chem. Phys., 23, 5335–5353, https://doi.org/10.5194/acp-23-5335-2023, https://doi.org/10.5194/acp-23-5335-2023, 2023
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Large-magnitude volcanic eruptions have the potential to alter large-scale circulation patterns, such as the quasi-biennial oscillation (QBO). The QBO is an oscillation of the tropical stratospheric zonal winds between easterly and westerly directions. Using a climate model, we show that large-magnitude eruptions can delay the progression of the QBO, with a much longer delay when the shear is easterly than when it is westerly. Such delays may affect weather and transport of atmospheric gases.
Dillon Elsbury, Amy H. Butler, John R. Albers, Melissa L. Breeden, and Andrew O'Neil Langford
Atmos. Chem. Phys., 23, 5101–5117, https://doi.org/10.5194/acp-23-5101-2023, https://doi.org/10.5194/acp-23-5101-2023, 2023
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One of the global hotspots where stratosphere-to-troposphere transport (STT) of ozone takes place is over Pacific North America (PNA). However, we do not know how or if STT over PNA will change in response to climate change. Using climate model experiments forced with
worst-casescenario Representative Concentration Pathway 8.5 climate change, we find that changes in net chemical production and transport of ozone in the lower stratosphere increase STT of ozone over PNA in the future.
Khalil Karami, Rolando Garcia, Christoph Jacobi, Jadwiga H. Richter, and Simone Tilmes
Atmos. Chem. Phys., 23, 3799–3818, https://doi.org/10.5194/acp-23-3799-2023, https://doi.org/10.5194/acp-23-3799-2023, 2023
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Alongside mitigation and adaptation efforts, stratospheric aerosol intervention (SAI) is increasingly considered a third pillar to combat dangerous climate change. We investigate the teleconnection between the quasi-biennial oscillation in the equatorial stratosphere and the Arctic stratospheric polar vortex under a warmer climate and an SAI scenario. We show that the Holton–Tan relationship weakens under both scenarios and discuss the physical mechanisms responsible for such changes.
Dirk Offermann, Christoph Kalicinsky, Ralf Koppmann, and Johannes Wintel
Atmos. Chem. Phys., 23, 3267–3278, https://doi.org/10.5194/acp-23-3267-2023, https://doi.org/10.5194/acp-23-3267-2023, 2023
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Atmospheric oscillations with periods between 5 and more than 200 years are believed to be self-excited (internal) in the atmosphere, i.e. non-anthropogenic. They are found at all altitudes up to 110 km and at four very different geographical locations (75° N, 70° E; 75° N, 280° E; 50° N, 7° E; 50° S, 7° E). Therefore, they hint at a global-oscillation mode. Their amplitudes are on the order of present-day climate trends, and it is therefore difficult to disentangle them.
Samuel Benito-Barca, Natalia Calvo, and Marta Abalos
Atmos. Chem. Phys., 22, 15729–15745, https://doi.org/10.5194/acp-22-15729-2022, https://doi.org/10.5194/acp-22-15729-2022, 2022
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The impact of different El Niño flavors (eastern (EP) and central (CP) Pacific El Niño) and La Niña on the stratospheric ozone is studied in a state-of-the-art chemistry–climate model. Ozone reduces in the tropics and increases in the extratropics when an EP El Niño event occurs, the opposite of La Niña. However, CP El Niño has no impact on extratropical ozone. These ozone variations are driven by changes in the stratospheric transport circulation, with an important contribution of mixing.
Nora Bergner, Marina Friedel, Daniela I. V. Domeisen, Darryn Waugh, and Gabriel Chiodo
Atmos. Chem. Phys., 22, 13915–13934, https://doi.org/10.5194/acp-22-13915-2022, https://doi.org/10.5194/acp-22-13915-2022, 2022
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Polar vortex extremes, particularly situations with an unusually weak cyclonic circulation in the stratosphere, can influence the surface climate in the spring–summer time in the Southern Hemisphere. Using chemistry-climate models and observations, we evaluate the robustness of the surface impacts. While models capture the general surface response, they do not show the observed climate patterns in midlatitude regions, which we trace back to biases in the models' circulations.
Stephen Bourguet and Marianna Linz
Atmos. Chem. Phys., 22, 13325–13339, https://doi.org/10.5194/acp-22-13325-2022, https://doi.org/10.5194/acp-22-13325-2022, 2022
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Here, we tested the impact of spatial and temporal resolution on Lagrangian trajectory studies in a key region of interest for climate feedbacks and stratospheric chemistry. Our analysis shows that new higher-resolution input data provide an opportunity for a better understanding of physical processes that control how air moves from the troposphere to the stratosphere. Future studies of how these processes will change in a warming climate will benefit from these results.
John R. Albers, Amy H. Butler, Andrew O. Langford, Dillon Elsbury, and Melissa L. Breeden
Atmos. Chem. Phys., 22, 13035–13048, https://doi.org/10.5194/acp-22-13035-2022, https://doi.org/10.5194/acp-22-13035-2022, 2022
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Ozone transported from the stratosphere contributes to background ozone concentrations in the free troposphere and to surface ozone exceedance events that affect human health. The physical processes whereby the El Niño–Southern Oscillation (ENSO) modulates North American stratosphere-to-troposphere ozone transport during spring are documented, and the usefulness of ENSO for predicting ozone events that may cause exceedances in surface air quality standards are assessed.
Axel Gabriel
Atmos. Chem. Phys., 22, 10425–10441, https://doi.org/10.5194/acp-22-10425-2022, https://doi.org/10.5194/acp-22-10425-2022, 2022
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Recent measurements show some evidence that the amplitudes of atmospheric gravity waves (horizontal wavelengths of 100–2000 km), which propagate from the troposphere (0–10 km) to the stratosphere and mesosphere (10–100 km), increase more strongly with height during daytime than during nighttime. This study shows that ozone–temperature coupling in the upper stratosphere can principally produce such an amplification. The results will help to improve atmospheric circulation models.
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, https://doi.org/10.5194/acp-22-9895-2022, https://doi.org/10.5194/acp-22-9895-2022, 2022
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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.
Ming Shangguan and Wuke Wang
Atmos. Chem. Phys., 22, 9499–9511, https://doi.org/10.5194/acp-22-9499-2022, https://doi.org/10.5194/acp-22-9499-2022, 2022
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Skilful predictions of weather and climate on subseasonal to seasonal scales are valuable for decision makers. Here we show the global spatiotemporal variation of the temperature SAO in the UTLS with GNSS RO and reanalysis data. The formation of the SAO is explained by an energy budget analysis. The results show that the SAO in the UTLS is partly modified by the SSTs according to model simulations. The results may provide an important source for seasonal predictions of the surface weather.
Oscar Dimdore-Miles, Lesley Gray, Scott Osprey, Jon Robson, Rowan Sutton, and Bablu Sinha
Atmos. Chem. Phys., 22, 4867–4893, https://doi.org/10.5194/acp-22-4867-2022, https://doi.org/10.5194/acp-22-4867-2022, 2022
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This study examines interactions between variations in the strength of polar stratospheric winds and circulation in the North Atlantic in a climate model simulation. It finds that the Atlantic Meridional Overturning Circulation (AMOC) responds with oscillations to sets of consecutive Northern Hemisphere winters, which show all strong or all weak polar vortex conditions. The study also shows that a set of strong vortex winters in the 1990s contributed to the recent slowdown in the observed AMOC.
Mengdie Xie, John C. Moore, Liyun Zhao, Michael Wolovick, and Helene Muri
Atmos. Chem. Phys., 22, 4581–4597, https://doi.org/10.5194/acp-22-4581-2022, https://doi.org/10.5194/acp-22-4581-2022, 2022
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We use data from six Earth system models to estimate Atlantic meridional overturning circulation (AMOC) changes and its drivers under four different solar geoengineering methods. Solar dimming seems relatively more effective than marine cloud brightening or stratospheric aerosol injection at reversing greenhouse-gas-driven declines in AMOC. Geoengineering-induced AMOC amelioration is due to better maintenance of air–sea temperature differences and reduced loss of Arctic summer sea ice.
Kai Qie, Wuke Wang, Wenshou Tian, Rui Huang, Mian Xu, Tao Wang, and Yifeng Peng
Atmos. Chem. Phys., 22, 4393–4411, https://doi.org/10.5194/acp-22-4393-2022, https://doi.org/10.5194/acp-22-4393-2022, 2022
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We identify a significantly intensified upward motion over the tropical western Pacific (TWP) and an enhanced tropical upwelling in boreal winter during 1958–2017 due to the warming of global sea surface temperatures (SSTs). Our results suggest that more tropospheric trace gases over the TWP could be elevated to the lower stratosphere, which implies that the emission from the maritime continent plays a more important role in the stratospheric processes and the global climate.
Audrey Lecouffe, Sophie Godin-Beekmann, Andrea Pazmiño, and Alain Hauchecorne
Atmos. Chem. Phys., 22, 4187–4200, https://doi.org/10.5194/acp-22-4187-2022, https://doi.org/10.5194/acp-22-4187-2022, 2022
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This study uses a model developped at LATMOS (France) to analyze the behavior of the Antarctic polar vortex from 1979 to 2020 at 675 K, 550 K, and 475 K isentropic levels. We found that the vortex edge intensity is stronger during the September–October–November period, while its edge position is less extended during this period. The polar vortex is stronger and lasts longer during solar minimum years. Breakup dates of the polar vortex are linked to the ozone hole and maximum wind speed.
Jan Clemens, Felix Ploeger, Paul Konopka, Raphael Portmann, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 22, 3841–3860, https://doi.org/10.5194/acp-22-3841-2022, https://doi.org/10.5194/acp-22-3841-2022, 2022
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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.
Adam A. Scaife, Mark P. Baldwin, Amy H. Butler, Andrew J. Charlton-Perez, Daniela I. V. Domeisen, Chaim I. Garfinkel, Steven C. Hardiman, Peter Haynes, Alexey Yu Karpechko, Eun-Pa Lim, Shunsuke Noguchi, Judith Perlwitz, Lorenzo Polvani, Jadwiga H. Richter, John Scinocca, Michael Sigmond, Theodore G. Shepherd, Seok-Woo Son, and David W. J. Thompson
Atmos. Chem. Phys., 22, 2601–2623, https://doi.org/10.5194/acp-22-2601-2022, https://doi.org/10.5194/acp-22-2601-2022, 2022
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Great progress has been made in computer modelling and simulation of the whole climate system, including the stratosphere. Since the late 20th century we also gained a much clearer understanding of how the stratosphere interacts with the lower atmosphere. The latest generation of numerical prediction systems now explicitly represents the stratosphere and its interaction with surface climate, and here we review its role in long-range predictions and projections from weeks to decades ahead.
Yihang Hu, Wenshou Tian, Jiankai Zhang, Tao Wang, and Mian Xu
Atmos. Chem. Phys., 22, 1575–1600, https://doi.org/10.5194/acp-22-1575-2022, https://doi.org/10.5194/acp-22-1575-2022, 2022
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Antarctic stratospheric wave activities in September have been weakening significantly since the 2000s. Further analysis supports the finding that sea surface temperature (SST) trends over 20° N–70° S lead to the weakening of stratospheric wave activities, while the response of stratospheric wave activities to ozone recovery is weak. Thus, the SST trend should be taken into consideration when exploring the mechanism for the climate transition in the southern hemispheric stratosphere around 2000.
Sheena Loeffel, Roland Eichinger, Hella Garny, Thomas Reddmann, Frauke Fritsch, Stefan Versick, Gabriele Stiller, and Florian Haenel
Atmos. Chem. Phys., 22, 1175–1193, https://doi.org/10.5194/acp-22-1175-2022, https://doi.org/10.5194/acp-22-1175-2022, 2022
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SF6-derived trends of stratospheric AoA from observations and model simulations disagree in sign. SF6 experiences chemical degradation, which we explicitly integrate in a global climate model. In our simulations, the AoA trend changes sign when SF6 sinks are considered; thus, the process has the potential to reconcile simulated with observed AoA trends. We show that the positive AoA trend is due to the SF6 sinks themselves and provide a first approach for a correction to account for SF6 loss.
Nicholas A. Davis, Patrick Callaghan, Isla R. Simpson, and Simone Tilmes
Atmos. Chem. Phys., 22, 197–214, https://doi.org/10.5194/acp-22-197-2022, https://doi.org/10.5194/acp-22-197-2022, 2022
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Specified dynamics schemes attempt to constrain the atmospheric circulation in a climate model to isolate the role of transport in chemical variability, evaluate model physics, and interpret field campaign observations. We show that the specified dynamics scheme in CESM2 erroneously suppresses convection and induces circulation errors that project onto errors in tracers, even using the most optimal settings. Development of a more sophisticated scheme is necessary for future progress.
Cornelia Strube, Peter Preusse, Manfred Ern, and Martin Riese
Atmos. Chem. Phys., 21, 18641–18668, https://doi.org/10.5194/acp-21-18641-2021, https://doi.org/10.5194/acp-21-18641-2021, 2021
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High gravity wave (GW) momentum fluxes in the lower stratospheric southern polar vortex around 60° S are still poorly understood. Few GW sources are found at these latitudes. We present a ray tracing case study on waves resolved in high-resolution global model temperatures southeast of New Zealand. We show that lateral propagation of more than 1000 km takes place below 20 km altitude, and a variety of orographic and non-orographic sources located north of 50° S generate the wave field.
Erika Brattich, Hongyu Liu, Bo Zhang, Miguel Ángel Hernández-Ceballos, Jussi Paatero, Darko Sarvan, Vladimir Djurdjevic, Laura Tositti, and Jelena Ajtić
Atmos. Chem. Phys., 21, 17927–17951, https://doi.org/10.5194/acp-21-17927-2021, https://doi.org/10.5194/acp-21-17927-2021, 2021
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In this study we analyse the output of a chemistry and transport model together with observations of different meteorological and compositional variables to demonstrate the link between sudden stratospheric warming and transport of stratospheric air to the surface in the subpolar regions of Europe during the cold season. Our findings have particular implications for atmospheric composition since climate projections indicate more frequent sudden stratospheric warming under a warmer climate.
Liang Tang, Sheng-Yang Gu, and Xian-Kang Dou
Atmos. Chem. Phys., 21, 17495–17512, https://doi.org/10.5194/acp-21-17495-2021, https://doi.org/10.5194/acp-21-17495-2021, 2021
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Our study explores the variation in the occurrence date, peak amplitude and wave period for eastward waves and the role of instability, background wind structure and the critical layer in eastward wave propagation and amplification.
Marta Abalos, Natalia Calvo, Samuel Benito-Barca, Hella Garny, Steven C. Hardiman, Pu Lin, Martin B. Andrews, Neal Butchart, Rolando Garcia, Clara Orbe, David Saint-Martin, Shingo Watanabe, and Kohei Yoshida
Atmos. Chem. Phys., 21, 13571–13591, https://doi.org/10.5194/acp-21-13571-2021, https://doi.org/10.5194/acp-21-13571-2021, 2021
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The stratospheric Brewer–Dobson circulation (BDC), responsible for transporting mass, tracers and heat globally in the stratosphere, is evaluated in a set of state-of-the-art climate models. The acceleration of the BDC in response to increasing greenhouse gases is most robust in the lower stratosphere. At higher levels, the well-known inconsistency between model and observational BDC trends can be partly reconciled by accounting for limited sampling and large uncertainties in the observations.
Zhihong Zhuo, Ingo Kirchner, Stephan Pfahl, and Ulrich Cubasch
Atmos. Chem. Phys., 21, 13425–13442, https://doi.org/10.5194/acp-21-13425-2021, https://doi.org/10.5194/acp-21-13425-2021, 2021
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The impact of volcanic eruptions varies with eruption season and latitude. This study simulated eruptions at different latitudes and in different seasons with a fully coupled climate model. The climate impacts of northern and southern hemispheric eruptions are reversed but are insensitive to eruption season. Results suggest that the regional climate impacts are due to the dynamical response of the climate system to radiative effects of volcanic aerosols and the subsequent regional feedbacks.
Min-Jee Kang and Hye-Yeong Chun
Atmos. Chem. Phys., 21, 9839–9857, https://doi.org/10.5194/acp-21-9839-2021, https://doi.org/10.5194/acp-21-9839-2021, 2021
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In winter 2019/20, the westerly quasi-biennial oscillation (QBO) phase was disrupted again by easterly winds. It is found that strong Rossby waves from the Southern Hemisphere weaken the jet core in early stages, and strong mixed Rossby–gravity waves reverse the wind in later stages. Inertia–gravity waves and small-scale convective gravity waves also provide negative forcing. These strong waves are attributed to an anomalous wind profile, barotropic instability, and slightly strong convection.
Henning Franke, Ulrike Niemeier, and Daniele Visioni
Atmos. Chem. Phys., 21, 8615–8635, https://doi.org/10.5194/acp-21-8615-2021, https://doi.org/10.5194/acp-21-8615-2021, 2021
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Stratospheric aerosol modification (SAM) can alter the quasi-biennial oscillation (QBO). Our simulations with two different models show that the characteristics of the QBO response are primarily determined by the meridional structure of the aerosol-induced heating. Therefore, the QBO response to SAM depends primarily on the location of injection, while injection type and rate act to scale the specific response. Our results have important implications for evaluating adverse side effects of SAM.
Mohamadou Diallo, Manfred Ern, and Felix Ploeger
Atmos. Chem. Phys., 21, 7515–7544, https://doi.org/10.5194/acp-21-7515-2021, https://doi.org/10.5194/acp-21-7515-2021, 2021
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Despite good agreement in the spatial structure, there are substantial differences in the strength of the Brewer–Dobson circulation (BDC) and its modulations in the UTLS and upper stratosphere. The tropical upwelling is generally weaker in ERA5 than in ERAI due to weaker planetary and gravity wave breaking in the UTLS. Analysis of the BDC trend shows an acceleration of the BDC of about 1.5 % decade-1 due to the long-term intensification in wave breaking, consistent with climate predictions.
Andrew Orr, Hua Lu, Patrick Martineau, Edwin P. Gerber, Gareth J. Marshall, and Thomas J. Bracegirdle
Atmos. Chem. Phys., 21, 7451–7472, https://doi.org/10.5194/acp-21-7451-2021, https://doi.org/10.5194/acp-21-7451-2021, 2021
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Reanalysis datasets combine observations and weather forecast simulations to create our best estimate of the state of the atmosphere and are important for climate monitoring. Differences in the technical details of these products mean that they may give different results. This study therefore examined how changes associated with the so-called Antarctic ozone hole are represented, which is one of the most important climate changes in recent decades, and showed that they were broadly consistent.
Tiehan Zhou, Kevin DallaSanta, Larissa Nazarenko, Gavin A. Schmidt, and Zhonghai Jin
Atmos. Chem. Phys., 21, 7395–7407, https://doi.org/10.5194/acp-21-7395-2021, https://doi.org/10.5194/acp-21-7395-2021, 2021
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Stratospheric radiative damping increases with rising CO2. Sensitivity experiments using the one-dimensional mechanistic models of the quasi-biennial oscillation (QBO) indicate a shortening of the simulated QBO period due to the enhancing of the radiative damping. This result suggests that increasing radiative damping may play a role in determining the QBO period in a warming climate along with wave momentum flux entering the stratosphere and tropical vertical residual velocity.
Simone Dietmüller, Hella Garny, Roland Eichinger, and William T. Ball
Atmos. Chem. Phys., 21, 6811–6837, https://doi.org/10.5194/acp-21-6811-2021, https://doi.org/10.5194/acp-21-6811-2021, 2021
Xiaolu Yan, Paul Konopka, Marius Hauck, Aurélien Podglajen, and Felix Ploeger
Atmos. Chem. Phys., 21, 6627–6645, https://doi.org/10.5194/acp-21-6627-2021, https://doi.org/10.5194/acp-21-6627-2021, 2021
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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.
Ioana Ivanciu, Katja Matthes, Sebastian Wahl, Jan Harlaß, and Arne Biastoch
Atmos. Chem. Phys., 21, 5777–5806, https://doi.org/10.5194/acp-21-5777-2021, https://doi.org/10.5194/acp-21-5777-2021, 2021
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The Antarctic ozone hole has driven substantial dynamical changes in the Southern Hemisphere atmosphere over the past decades. This study separates the historical impacts of ozone depletion from those of rising levels of greenhouse gases and investigates how these impacts are captured in two types of climate models: one using interactive atmospheric chemistry and one prescribing the CMIP6 ozone field. The effects of ozone depletion are more pronounced in the model with interactive chemistry.
Luis F. Millán, Gloria L. Manney, and Zachary D. Lawrence
Atmos. Chem. Phys., 21, 5355–5376, https://doi.org/10.5194/acp-21-5355-2021, https://doi.org/10.5194/acp-21-5355-2021, 2021
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We assess how consistently reanalyses represent potential vorticity (PV) among each other. PV helps describe dynamical processes in the stratosphere because it acts approximately as a tracer of the movement of air parcels; it is extensively used to identify the location of the tropopause and to identify and characterize the stratospheric polar vortex. Overall, PV from all reanalyses agrees well with the reanalysis ensemble mean.
Chaim I. Garfinkel, Ohad Harari, Shlomi Ziskin Ziv, Jian Rao, Olaf Morgenstern, Guang Zeng, Simone Tilmes, Douglas Kinnison, Fiona M. O'Connor, Neal Butchart, Makoto Deushi, Patrick Jöckel, Andrea Pozzer, and Sean Davis
Atmos. Chem. Phys., 21, 3725–3740, https://doi.org/10.5194/acp-21-3725-2021, https://doi.org/10.5194/acp-21-3725-2021, 2021
Short summary
Short summary
Water vapor is the dominant greenhouse gas in the atmosphere, and El Niño is the dominant mode of variability in the ocean–atmosphere system. The connection between El Niño and water vapor above ~ 17 km is unclear, with single-model studies reaching a range of conclusions. This study examines this connection in 12 different models. While there are substantial differences among the models, all models appear to capture the fundamental physical processes correctly.
Cited articles
AIRS/Aqua Observations of Gravity Waves, re3data.org – Registry of Research Data Repositories, http://doi.org/10.17616/R34J42, 2020.
Alexander, J. M. and Teitelbaum, H.: Observation and analysis of a large
amplitude mountain wave event over the Antarctic Peninsula, J. Geophys.
Res., 112, D21103, https://doi.org/10.1029/2006JD008368, 2007.
Alexander, S. P., Klekociuk, A. R., Pitts, M. C., McDonald, A. J., and
Arevalo-Torres, A.: The effect of orographic gravity waves on Antarctic
polar stratosphere cloud occurrence and composition, J. Geophys. Res., 116, D06109, https://doi.org/10.1029/2010JD015184, 2011.
Alexander, S. P., Klekociuk, A. R., McDonald, A. J., and Pitts, M. C.:
Quantifying the role of orographic gravity waves on polar stratospheric
cloud occurrence in the Antarctic and the Arctic, J. Geophys. Res., 118,
11493–11507, https://doi.org/10.1002/2013JD020122, 2013.
Alexander, S., Orr, A., Webster, S., and Murphy, D.: Observations and
fine-scale model simulations of gravity waves over Davis, East Antarctica
(69∘ S, 78∘ E), J. Geophys. Res., 122, 7355–7370, https://doi.org/10.1002/2017JD026615, 2017.
Alfred, J., Fromm, M., Bevilacqua, R., Nedoluha, G., Strawa, A., Poole, L., and Wickert, J.: Observations and analysis of polar stratospheric clouds detected by POAM III and SAGE III during the SOLVE II/VINTERSOL campaign in the 2002/2003 Northern Hemisphere winter, Atmos. Chem. Phys., 7, 2151–2163, https://doi.org/10.5194/acp-7-2151-2007, 2007.
Bacmeister, J. T., Schoeberl, M. R., Lait, L. R., Newman, P. A., and Gary,
B.: ER-2 mountain wave encounter over Antarctica: Evidence for blocking,
Geophys. Res. Lett., 17, 81–84, https://doi.org/10.1029/GL017i001p00081,1990.
Bramberger, M., Dörnbrack, A., Bossert, K., Ehard, B., Fritts, D. C., Kaifler, B., Mallaun, C., Orr, A., Pautet, P.-Dominique, Rapp, M., Taylor, M. J., Vosper, S., Williams, B. P., and Witschas, B.: Does strong tropospheric forcing cause large-amplitude mesospheric gravity waves? A DEEPWAVE case study, J. Geophys. Res., 122, 11422–11443, https://doi.org/10.1002/2017JD027371, 2017.
British Antarctic Survey: high resolution radiosonde data from Halley and Rothera stations, NCAS British Atmospheric Data Centre, 2020, http://catalogue.ceda.ac.uk/uuid/37f2bef57e28bcd780a5cbfe077f4bf8, 2008.
Campbell, J. R. and Sassen, K.: Polar stratospheric clouds at the South Pole
from 5 years of continuous lidar data: Macrophysical, optical, and
thermodynamic properties, J. Geophys. Res., 113, D20204,
https://doi.org/10.1029/2007JD009680, 2008.
Carslaw, K., Wirth, M., Tsias, A., Luo, B. P., Dörnbrack, A.,
Leutbecher, M., Volkert, H., Renger, W., Bacmeister, J. T., Reimer, E., and
Peter, Th.: Increased stratospheric ozone depletion due to mountain-induced atmospheric waves, Nature, 391, 675–678, https://doi.org/10.1038/35589, 1998.
Chiodo, G. and Polvani, L. M.: Reduced Southern Hemisphere circulation
response to quadrupled CO2 due to stratospheric ozone feedback,
Geophys. Res. Lett., 44, 465–474, https://doi.org/10.1002/2016GL071011, 2017.
Chipperfield, M. P.: Multiannual simulations with a 3D chemical transport
model, J. Geophys. Res., 104, 1781–1805, https://doi.org/10.1029/98JD02597, 1999.
Dean, S. M., Flowerdew, J., Lawrence, B. N., and Eckermann, S. D.:
Parameterisation of orographic cloud dynamics in a GCM, Clim. Dynam., 28,
581–597, https://doi.org/10.1007/s00382-006-0202-0, 2007.
Dörnbrack, A., Leutbecher, M., Kivi, R., and Kyrö, E.: Mountain
wave-induced record low stratospheric temperatures above northern
Scandinavia, Tellus, 51, 951–963, https://doi.org/10.1034/j.1600-0870.1999.00028.x,
1999.
Dörnbrack, A. and Leutbecher, M.: Relevance of mountain waves for the
formation of polar stratospheric clouds over Scandinavia: A 20-year
climatology, J. Geophys. Res., 106, 1583–1593, https://doi.org/10.1029/2000JD900250,
2001.
Dörnbrack, A., Birner, T., Fix, A., Flentje, H., Meister, A., Schmid,
H., Browell, E. V., and Mahoney, M. J.: Evidence for inertia gravity waves
forming in polar stratospheric clouds over Scandinavia, J. Geophys. Res.,
107, 8287, https://doi.org/10.1029/2001JD000452, 2002.
Eckermann, S. D., Hoffmann, L., Höpfner, M., Wu, D. L., and Alexander,
M. J.: Antarctic NAT PSC belt of June 2003: Observational validation of the
mountain wave seeding hypothesis, Geophys. Res. Lett., 36, L02807,
https://doi.org/10.1029/2008GL036629, 2009.
Eyring, V., Arblaster, J. M., Cionni, I., Sedlácek, J., Perlwitz, J.,
Young, P. J., Bekki, S., Bergmann, D., Cameron-Smith, P., Collins, W. J.,
Faluvegi, G., Gottschaldt, K.-D., Horowitz, L. W., Kinnison, D. E.,
Lamarque, J.-F., Marsh, D. R., Saint-Martin, D., Shindell, D. T., Sudo, K.,
Szopa, S., and Watanabe, S.: Long-term ozone changes and associated climate
impacts in CMIP5 simulations, J. Geophys. Res., 118, 5029–5060, https://doi.org/10.1002/jgrd.50316, 2013.
Fahey, D. W., Kelly, K. K., Kawa, S. R., Tuck, A. F., Loewenstein, M., Chan,
K. R., and Heidt, L. E.: Observations of denitrification and dehydration in
the winter polar stratospheres, Nature, 344, 321–324, https://doi.org/10.1038/344321a0, 1990.
Farman, J., Gardiner, B., and Shanklin, J.: Large losses of total ozone in
Antarctica reveal seasonal ClOx/NOx interaction, Nature,
315, 207–210, https://doi.org/10.1038/315207a0, 1985.
Fretwell, P., Pritchard, H. D., Vaughan, D. G., Bamber, J. L., Barrand, N. E., Bell, R., Bianchi, C., Bingham, R. G., Blankenship, D. D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A. J., Corr, H. F. J., Damaske, D., Damm, V., Ferraccioli, F., Forsberg, R., Fujita, S., Gim, Y., Gogineni, P., Griggs, J. A., Hindmarsh, R. C. A., Holmlund, P., Holt, J. W., Jacobel, R. W., Jenkins, A., Jokat, W., Jordan, T., King, E. C., Kohler, J., Krabill, W., Riger-Kusk, M., Langley, K. A., Leitchenkov, G., Leuschen, C., Luyendyk, B. P., Matsuoka, K., Mouginot, J., Nitsche, F. O., Nogi, Y., Nost, O. A., Popov, S. V., Rignot, E., Rippin, D. M., Rivera, A., Roberts, J., Ross, N., Siegert, M. J., Smith, A. M., Steinhage, D., Studinger, M., Sun, B., Tinto, B. K., Welch, B. C., Wilson, D., Young, D. A., Xiangbin, C., and Zirizzotti, A.: Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375–393, https://doi.org/10.5194/tc-7-375-2013, 2013.
Goff, J. A.: Saturation pressure of water on the new Kelvin temperature scale, Trans. Am. Soc. Heating and Vent. Eng., 63, 347–354, 1957.
Hanson, D. and Mauersberger, K.: Laboratory studies of the nitric acid
trihydrate: implications for the south polar stratosphere, Geophys. Res. Lett., 15, 855–858, https://doi.org/10.1029/GL015i008p00855, 1988.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Joaquín, M.-S., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara , G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020.
Hewitt, H. T., Copsey, D., Culverwell, I. D., Harris, C. M., Hill, R. S. R., Keen, A. B., McLaren, A. J., and Hunke, E. C.: Design and implementation of the infrastructure of HadGEM3: the next-generation Met Office climate modelling system, Geosci. Model Dev., 4, 223–253, https://doi.org/10.5194/gmd-4-223-2011, 2011.
Hoffmann, L., Xue, X., and Alexander, M. J.: A global view of stratospheric
gravity wave hotspots located with Atmospheric Infrared Sounder
observations, J. Geophys. Res., 118, 416–434, https://doi.org/10.1029/2012JD018658,
2013.
Hoffmann, L., Grimsdell, A. W., and Alexander, M. J.: Stratospheric gravity waves at Southern Hemisphere orographic hotspots: 2003–2014 AIRS/Aqua observations, Atmos. Chem. Phys., 16, 9381–9397, https://doi.org/10.5194/acp-16-9381-2016, 2016.
Hoffmann, L., Spang, R., Orr, A., Alexander, M. J., Holt, L. A., and Stein, O.: A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation, Atmos. Chem. Phys., 17, 2901–2920, https://doi.org/10.5194/acp-17-2901-2017, 2017.
Iglesias-Suarez, F., Young, P. J., and Wild, O.: Stratospheric ozone change and related climate impacts over 1850–2100 as modelled by the ACCMIP ensemble, Atmos. Chem. Phys., 16, 343–363, https://doi.org/10.5194/acp-16-343-2016, 2016.
Keeble, J., Braesicke, P., Abraham, N. L., Roscoe, H. K., and Pyle, J. A.: The impact of polar stratospheric ozone loss on Southern Hemisphere stratospheric circulation and climate, Atmos. Chem. Phys., 14, 13705–13717, https://doi.org/10.5194/acp-14-13705-2014, 2014.
Kruse, C. G., Smith, R. B., and Eckermann, S. D.: The midlatitude
lower-stratospheric mountain wave “valve layer”, J. Atmos. Sci., 73,
5081–5100, https://doi.org/10.1175/JAS-D-16-0173.1, 2016.
Marti, J. and Mauersberger, K.: A survey and new measurements of ice vapour
pressure at temperatures between 170 and 250 K, Geophys. Res. Lett., 20,
363–366, https://doi.org/10.1029/93GL00105, 1993.
McDonald, A. J., George, S. E., and Woollands, R. M.: Can gravity waves significantly impact PSC occurrence in the Antarctic?, Atmos. Chem. Phys., 9, 8825–8840, https://doi.org/10.5194/acp-9-8825-2009, 2009.
McLandress, C., Jonsson, A. I., Plummer, D. A., Reader, M. C., Scinocca, J.
F., and Shepherd, T. G.: Separating the dynamical effects of climate change
and ozone depletion, Part I: Southern Hemisphere stratosphere, J. Climate,
23, 5002–5020, https://doi.org/10.1175/2010JCLI3586.1, 2010.
Moffat-Griffin, T., Hibbins, R. E., Jarvis, M. J., and Colwell, S. R.:
Seasonal variations of gravity wave activity in the lower stratosphere over
an Antarctic Peninsula station, J. Geophys. Res., 116, D14111,
https://doi.org/10.1029/2010JD015349, 2011.
Morgenstern, O., Braesicke, P., O'Connor, F. M., Bushell, A. C., Johnson, C. E., Osprey, S. M., and Pyle, J. A.: Evaluation of the new UKCA climate-composition model – Part 1: The stratosphere, Geosci. Model Dev., 2, 43–57, https://doi.org/10.5194/gmd-2-43-2009, 2009.
Noel, V., Hertzog, A., and Chepfer, H.: CALIPSO observations of wave-induced
PSCs with near-unity optical depth over Antarctica in 2006–2007, J.
Geophys. Res., 114, D05202, https://doi.org/10.1029/2008JD010604, 2009.
Orr, A., Marshall, G., Hunt, J. C. R., Sommeria, J., Wang, C., van Lipzig,
N., Cresswell, D., and King, J. C.: Characteristics of airflow over the
Antarctic Peninsula and its response to recent strengthening of westerly
circumpolar winds, J. Atmos. Sci., 65, 1396–1413,
https://doi.org/10.1175/2007JAS2498.1, 2008.
Orr, A., Bracegirdle, T. J., Hoskings, J. S., Jung, T., Haigh, J. D.,
Phillips, T., and Feng, W.: Possible dynamical mechanisms for Southern
Hemisphere climate change due to the ozone hole, J. Atmos. Sci., 69,
2917–2932, https://doi.org/10.1175/JAS-D-11-0210.1, 2012.
Orr, A., Hosking, J. S., Hoffmann, L., Keeble, J., Dean, S. M., Roscoe, H. K., Abraham, N. L., Vosper, S., and Braesicke, P.: Inclusion of mountain-wave-induced cooling for the formation of PSCs over the Antarctic Peninsula in a chemistry–climate model, Atmos. Chem. Phys., 15, 1071–1086, https://doi.org/10.5194/acp-15-1071-2015, 2015.
Pawson, S., Naujokat, B., and Labitzke, K.: On the polar stratospheric cloud
formation potential of the northern stratosphere, J. Geophys. Res., 100,
23215–23225, https://doi.org/10.1029/95JD01918, 1995.
Plougonven, R., Hertzog, A., and Teitelbaum, H.: Observations and
simulations of large-amplitude mountain wave breaking over the Antarctic
Peninsula, J. Geophys. Res., 113, D16113, https://doi.org/10.1029/2007JD009739, 2008.
Plougonven, R., Hertzog, A., and Guez, L.: Gravity waves over Antarctica and
the Southern Ocean: consistent momentum fluxes in mesoscale simulations and
stratospheric balloon observations, Q. J. Roy. Meteor. Soc., 139, 101–118,
https://doi.org/10.1002/qj.1965, 2012.
Polvani, L. M., Waugh, D. W., Correa, G. J. P., and Son, S.-W.:
Stratospheric ozone depletion: The main driver of twentieth-century
atmospheric circulation changes in the Southern Hemisphere, J. Climate,
24, 795–812, https://doi.org/10.1175/2010JCLI3772.1, 2011.
Pope, J. O., Orr, A., Marshall, G. J., and Abraham, N. L.: Non‐additive response of the high‐latitude Southern Hemisphere climate to aerosol forcing in a climate model with interactive chemistry. Atmos Sci Lett. e1004, https://doi.org/10.1002/asl.1004, 2020.
Preusse, P., Dörnbrack, A., Eckermann, S. D., Riese, M., Schaeler, B., Bacmeister, J. T., Broutman, D., and Grossmann, K. U.: Space‐based measurements of stratospheric mountain waves by CRISTA 1, sensitivity, analysis method, and a case study, J. Geophys. Res., 107, 8178, https://doi.org/10.1029/2001JD000699, 2002.
Previdi, M. and Polvani, L. M.: Climate system response to stratospheric
ozone depletion and recovery, Q. J. Roy. Meteor. Soc., 140, 2401–2419, https://doi.org/10.1002/qj.2330, 2014.
Sato, K., Tateno, S., Watanabe, S., and Kawatani, Y.: Gravity wave
characteristics in the Southern Hemisphere revealed by a high-resolution
middle-atmosphere general circulation model, J. Atmos. Sci., 69, 1378–1396,
https://doi.org/10.1175/JAS-D-11-0101.1, 2012.
Schröter, J., Rieger, D., Stassen, C., Vogel, H., Weimer, M., Werchner, S., Förstner, J., Prill, F., Reinert, D., Zängl, G., Giorgetta, M., Ruhnke, R., Vogel, B., and Braesicke, P.: ICON-ART 2.1: a flexible tracer framework and its application for composition studies in numerical weather forecasting and climate simulations, Geosci. Model Dev., 11, 4043–4068, https://doi.org/10.5194/gmd-11-4043-2018, 2018.
Solomon, S.: Stratospheric ozone depletion: A review of concepts and
history, Rev. Geophys., 37, 275–316, https://doi.org/10.1029/1999RG900008, 1999.
Solomon, S., Garcia, R. R., Rowland, F. S., and Wuebbles, D. J.: On the
depletion of Antarctic ozone, Nature, 321, 755–758, 1986.
Son, S.-W., Gerber, E. P., Perlwitz, J., Polvani, L. M., Gillett, N. P.,
Seo, K.-H., Eyring, V., Shepherd, T. G., Waugh, D., Akiyoshi, H., Austin,
J., Baumgaertner, A., Bekki, S., Braesicke, P., Bruhl, C., Butchart, N.,
Chipperfield, M. P., Cugnet, D., Dameris, M., Dhomse, S., Frith, S., Garny,
H., Garcia, R., Hardiman, S, C., Jockel, P., Lamarque, J. F., Mancini, E.,
Marchand, M., Michou, M., Nakamura, T., Morgenstern, O., Pitari, G.,
Plummer, D. A., Pyle, J., Rozanov, E., Scinocca, J. F., Shibata, K., Smale,
D., Teyssedre, H., Tian, W., and Yamashita, Y.: Impact of stratospheric
ozone on Southern Hemisphere circulation change: a multimodel assessment, J.
Geophys. Res., 115, D00M07, https://doi.org/10.1029/2010JD014271, 2010.
Spang, R., Hoffmann, L., Müller, R., Grooß, J.-U., Tritscher, I., Höpfner, M., Pitts, M., Orr, A., and Riese, M.: A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations, Atmos. Chem. Phys., 18, 5089–5113, https://doi.org/10.5194/acp-18-5089-2018, 2018.
Teitelbaum, H., Moustaoui, M., and Fromm, M.: Exploring polar stratospheric
cloud and ozone minihole formation: The primary importance of synoptic-scale
flow perturbations, J. Geophys. Res., 106, 28173–28188, https://doi.org/10.1029/2000JD000065, 2001.
Thompson, D. W. J. and Solomon, S.: Interpretation of recent southern
hemisphere climate change, Science, 296, 895–899, https://doi.org/10.1126/science.1069270, 2002.
Thompson, D. W. J. and Wallace, J. M.: Annular modes in the extratropical
circulation, Part I: Month-to-month variability, J. Climate, 13, 1000–1016,
https://doi.org/10.1175/1520-0442(2000)013<1000:AMITEC>2.0.CO;2, 2000.
Wu, D. L. and Eckermann, S. D.: Global gravity wave variances from Aura MLS:
Characteristics and interpretation, J. Atmos. Sci., 65, 3695–3718,
https://doi.org/10.1175/2008JAS2489.1, 2008.
Short summary
Polar stratospheric clouds (PSCs) are clouds found in the Antarctic winter stratosphere and are implicated in the formation of the ozone hole. These clouds can sometimes be formed or enhanced by mountain waves, formed as air passes over hills or mountains. However, this important mechanism is missing in coarse-resolution climate models, limiting our ability to simulate ozone. This study examines an attempt to include the effects of mountain waves and their impact on PSCs and ozone.
Polar stratospheric clouds (PSCs) are clouds found in the Antarctic winter stratosphere and are...
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