Articles | Volume 2, issue 3
https://doi.org/10.5194/wcd-2-631-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wcd-2-631-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
23 Jul 2021
Research article |
| 23 Jul 2021
| 23 Jul 2021
On the occurrence of strong vertical wind shear in the tropopause region: a 10-year ERA5 northern hemispheric study
Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
Daniel Kunkel
Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
Peter Hoor
Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
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Heiko Bozem, Peter Hoor, Daniel Kunkel, Franziska Köllner, Johannes Schneider, Andreas Herber, Hannes Schulz, W. Richard Leaitch, Amir A. Aliabadi, Megan D. Willis, Julia Burkart, and Jonathan P. D. Abbatt
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Daniel Kunkel, Peter Hoor, Thorsten Kaluza, Jörn Ungermann, Björn Kluschat, Andreas Giez, Hans-Christoph Lachnitt, Martin Kaufmann, and Martin Riese
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The Arctic is experiencing considerable environmental change with climate warming, illustrated by the dramatic decrease in sea-ice extent. It is important to understand both the natural and perturbed Arctic systems to gain a better understanding of how they will change in the future. This paper summarizes new insights into the relationships between Arctic aerosol particles and climate, as learned over the past five or so years by a large Canadian research consortium, NETCARE.
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Erlend M. Knudsen, Bernd Heinold, Sandro Dahlke, Heiko Bozem, Susanne Crewell, Irina V. Gorodetskaya, Georg Heygster, Daniel Kunkel, Marion Maturilli, Mario Mech, Carolina Viceto, Annette Rinke, Holger Schmithüsen, André Ehrlich, Andreas Macke, Christof Lüpkes, and Manfred Wendisch
Atmos. Chem. Phys., 18, 17995–18022, https://doi.org/10.5194/acp-18-17995-2018, https://doi.org/10.5194/acp-18-17995-2018, 2018
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The paper describes the synoptic development during the ACLOUD/PASCAL airborne and ship-based field campaign near Svalbard in spring 2017. This development is presented using near-surface and upperair meteorological observations, satellite, and model data. We first present time series of these data, from which we identify and characterize three key periods. Finally, we put our observations in historical and regional contexts and compare our findings to other Arctic field campaigns.
Emma L. Mungall, Jonathan P. D. Abbatt, Jeremy J. B. Wentzell, Gregory R. Wentworth, Jennifer G. Murphy, Daniel Kunkel, Ellen Gute, David W. Tarasick, Sangeeta Sharma, Christopher J. Cox, Taneil Uttal, and John Liggio
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Jens Krause, Peter Hoor, Andreas Engel, Felix Plöger, Jens-Uwe Grooß, Harald Bönisch, Timo Keber, Björn-Martin Sinnhuber, Wolfgang Woiwode, and Hermann Oelhaf
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Katrina M. Macdonald, Sangeeta Sharma, Desiree Toom, Alina Chivulescu, Andrew Platt, Mike Elsasser, Lin Huang, Richard Leaitch, Nathan Chellman, Joseph R. McConnell, Heiko Bozem, Daniel Kunkel, Ying Duan Lei, Cheol-Heon Jeong, Jonathan P. D. Abbatt, and Greg J. Evans
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The sources of key contaminants in Arctic snow may be an important factor in understanding the rapid climate changes observed in the Arctic. Fresh snow samples collected frequently through the winter season were analyzed for major constituents. Temporally refined source apportionment via positive matrix factorization in conjunction with FLEXPART suggested potential source characteristics and locations. The identity of these sources and their relative contribution to key analytes is discussed.
Christian Rolf, Bärbel Vogel, Peter Hoor, Armin Afchine, Gebhard Günther, Martina Krämer, Rolf Müller, Stefan Müller, Nicole Spelten, and Martin Riese
Atmos. Chem. Phys., 18, 2973–2983, https://doi.org/10.5194/acp-18-2973-2018, https://doi.org/10.5194/acp-18-2973-2018, 2018
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The Asian monsoon is a pronounced circulation system linked to rapid vertical transport of surface air from India and east Asia in the summer months. We found, based on aircraft measurements, higher concentration of water vapor in the lowermost stratosphere caused by the Asian monsoon. Enrichment of water vapor concentrations in the lowermost stratosphere impacts the radiation budget and thus climate. Understanding those variations in water vapor is important for climate projections.
Franziska Köllner, Johannes Schneider, Megan D. Willis, Thomas Klimach, Frank Helleis, Heiko Bozem, Daniel Kunkel, Peter Hoor, Julia Burkart, W. Richard Leaitch, Amir A. Aliabadi, Jonathan P. D. Abbatt, Andreas B. Herber, and Stephan Borrmann
Atmos. Chem. Phys., 17, 13747–13766, https://doi.org/10.5194/acp-17-13747-2017, https://doi.org/10.5194/acp-17-13747-2017, 2017
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We conducted aircraft-based single particle chemical composition measurements in the Canadian high Arctic during summer. Our results provide evidence for a marine-biogenic influence on secondary formation of particulate trimethylamine in the Arctic boundary layer. Understanding emission sources and further processes controlling aerosol number concentration and chemical composition in the pristine Arctic summer is crucial for modeling future climate in the area.
Tilman Hüneke, Oliver-Alex Aderhold, Jannik Bounin, Marcel Dorf, Eric Gentry, Katja Grossmann, Jens-Uwe Grooß, Peter Hoor, Patrick Jöckel, Mareike Kenntner, Marvin Knapp, Matthias Knecht, Dominique Lörks, Sabrina Ludmann, Sigrun Matthes, Rasmus Raecke, Marcel Reichert, Jannis Weimar, Bodo Werner, Andreas Zahn, Helmut Ziereis, and Klaus Pfeilsticker
Atmos. Meas. Tech., 10, 4209–4234, https://doi.org/10.5194/amt-10-4209-2017, https://doi.org/10.5194/amt-10-4209-2017, 2017
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This paper describes a novel instrument for the aircraft-borne remote sensing of trace gases and liquid and solid water. Until recently, such measurements could only be evaluated under clear-sky conditions. We present a characterization and error assessment of the novel "scaling method", which allows for the retrieval of absolute trace gas concentrations under all sky conditions, significantly expanding the applicability of such measurements to study atmospheric photochemistry.
Douglas B. Collins, Julia Burkart, Rachel Y.-W. Chang, Martine Lizotte, Aude Boivin-Rioux, Marjolaine Blais, Emma L. Mungall, Matthew Boyer, Victoria E. Irish, Guillaume Massé, Daniel Kunkel, Jean-Éric Tremblay, Tim Papakyriakou, Allan K. Bertram, Heiko Bozem, Michel Gosselin, Maurice Levasseur, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 17, 13119–13138, https://doi.org/10.5194/acp-17-13119-2017, https://doi.org/10.5194/acp-17-13119-2017, 2017
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The sources of aerosol particles and their growth to sizes large enough to act as cloud droplet seeds is of major importance to climate since clouds exert substantial control over the atmospheric energy balance. Using ship-board measurements from two summers in the Canadian Arctic, aerosol formation events were related to co-sampled atmospheric and oceanic parameters, providing insight into factors that drive particle formation and motivating further study of ocean–atmosphere interactions.
Marcus Klingebiel, André Ehrlich, Fanny Finger, Timo Röschenthaler, Suad Jakirlić, Matthias Voigt, Stefan Müller, Rolf Maser, Manfred Wendisch, Peter Hoor, Peter Spichtinger, and Stephan Borrmann
Atmos. Meas. Tech., 10, 3485–3498, https://doi.org/10.5194/amt-10-3485-2017, https://doi.org/10.5194/amt-10-3485-2017, 2017
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Microphysical and radiation measurements were collected with the unique AIRcraft TOwed Sensor Shuttle (AIRTOSS) – Learjet tandem platform. It is a combination of a Learjet 35A research aircraft and an instrumented aerodynamic bird, which can be detached from and retracted back to the aircraft during flight.
AIRTOSS and Learjet are equipped with radiative, cloud microphysical, trace gas,
and meteorological instruments to study cirrus clouds.
Roya Ghahreman, Ann-Lise Norman, Betty Croft, Randall V. Martin, Jeffrey R. Pierce, Julia Burkart, Ofelia Rempillo, Heiko Bozem, Daniel Kunkel, Jennie L. Thomas, Amir A. Aliabadi, Gregory R. Wentworth, Maurice Levasseur, Ralf M. Staebler, Sangeeta Sharma, and W. Richard Leaitch
Atmos. Chem. Phys., 17, 8757–8770, https://doi.org/10.5194/acp-17-8757-2017, https://doi.org/10.5194/acp-17-8757-2017, 2017
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We present spring and summertime vertical profile measurements of Arctic dimethyl sulfide (DMS), together with model simulations to consider what these profiles indicate about DMS sources and lifetimes in the Arctic. Our results highlight the role of local open water as the source of DMS(g) during July 2014 and the influence of long-range transport of DMS(g) from further afield in the Arctic during April 2015.
Andrea Mues, Maheswar Rupakheti, Christoph Münkel, Axel Lauer, Heiko Bozem, Peter Hoor, Tim Butler, and Mark G. Lawrence
Atmos. Chem. Phys., 17, 8157–8176, https://doi.org/10.5194/acp-17-8157-2017, https://doi.org/10.5194/acp-17-8157-2017, 2017
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Ceilometer measurements taken in the Kathmandu Valley, Nepal, were used to study the temporal and spatial evolution of the mixing layer height in the valley. This provides important information on the vertical structure of the atmosphere and can thus also help to understand the mixing of air pollutants (e.g. black carbon) in the valley. The seasonal and diurnal cycles of the mixing layer were found to be highly dependent on meteorology and mainly anticorrelated to black carbon concentrations.
Klaus-D. Gottschaldt, Hans Schlager, Robert Baumann, Heiko Bozem, Veronika Eyring, Peter Hoor, Patrick Jöckel, Tina Jurkat, Christiane Voigt, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 17, 6091–6111, https://doi.org/10.5194/acp-17-6091-2017, https://doi.org/10.5194/acp-17-6091-2017, 2017
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We present upper-tropospheric trace gas measurements in the Asian summer monsoon anticyclone, obtained with the HALO research aircraft in September 2012. The anticyclone is one of the largest atmospheric features on Earth, but many aspects of it are not well understood. With the help of model simulations we find that entrainments from the tropopause region and the lower troposphere, combined with photochemistry and dynamical instabilities, can explain the observations.
Katrina M. Macdonald, Sangeeta Sharma, Desiree Toom, Alina Chivulescu, Sarah Hanna, Allan K. Bertram, Andrew Platt, Mike Elsasser, Lin Huang, David Tarasick, Nathan Chellman, Joseph R. McConnell, Heiko Bozem, Daniel Kunkel, Ying Duan Lei, Greg J. Evans, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 17, 5775–5788, https://doi.org/10.5194/acp-17-5775-2017, https://doi.org/10.5194/acp-17-5775-2017, 2017
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Rapid climate changes within the Arctic have highlighted existing uncertainties in the transport of contaminants to Arctic snow. Fresh snow samples collected frequently through the winter season were analyzed for major constituents creating a unique record of Arctic snow. Comparison with simultaneous atmospheric measurements provides insight into the driving processes in the transfer of contaminants from air to snow. The relative importance of deposition mechanisms over the season is proposed.
Julia Burkart, Megan D. Willis, Heiko Bozem, Jennie L. Thomas, Kathy Law, Peter Hoor, Amir A. Aliabadi, Franziska Köllner, Johannes Schneider, Andreas Herber, Jonathan P. D. Abbatt, and W. Richard Leaitch
Atmos. Chem. Phys., 17, 5515–5535, https://doi.org/10.5194/acp-17-5515-2017, https://doi.org/10.5194/acp-17-5515-2017, 2017
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Our aircraft study for the first time systematically investigates aerosol size distributions, including ultrafine particles (5–20 nm in diameter), in the Arctic summertime atmosphere. We find that ultrafine particles occur very frequently in the boundary layer and not aloft, suggesting a surface source of these particles. Understanding aerosol properties and sources is crucial to predict climate and especially important in the Arctic as this region responds extremely fast to climate change.
Johannes Wagner, Andreas Dörnbrack, Markus Rapp, Sonja Gisinger, Benedikt Ehard, Martina Bramberger, Benjamin Witschas, Fernando Chouza, Stephan Rahm, Christian Mallaun, Gerd Baumgarten, and Peter Hoor
Atmos. Chem. Phys., 17, 4031–4052, https://doi.org/10.5194/acp-17-4031-2017, https://doi.org/10.5194/acp-17-4031-2017, 2017
Bärbel Vogel, Gebhard Günther, Rolf Müller, Jens-Uwe Grooß, Armin Afchine, Heiko Bozem, Peter Hoor, Martina Krämer, Stefan Müller, Martin Riese, Christian Rolf, Nicole Spelten, Gabriele P. Stiller, Jörn Ungermann, and Andreas Zahn
Atmos. Chem. Phys., 16, 15301–15325, https://doi.org/10.5194/acp-16-15301-2016, https://doi.org/10.5194/acp-16-15301-2016, 2016
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The identification of transport pathways from the Asian monsoon anticyclone into the lower stratosphere is unclear. Global simulations with the CLaMS model demonstrate that source regions in Asia and in the Pacific Ocean have a significant impact on the chemical composition of the lower stratosphere of the Northern Hemisphere by flooding the extratropical lower stratosphere with young moist air masses. Two main horizontal transport pathways from the Asian monsoon anticyclone are identified.
W. Richard Leaitch, Alexei Korolev, Amir A. Aliabadi, Julia Burkart, Megan D. Willis, Jonathan P. D. Abbatt, Heiko Bozem, Peter Hoor, Franziska Köllner, Johannes Schneider, Andreas Herber, Christian Konrad, and Ralf Brauner
Atmos. Chem. Phys., 16, 11107–11124, https://doi.org/10.5194/acp-16-11107-2016, https://doi.org/10.5194/acp-16-11107-2016, 2016
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Thought to be mostly unimportant for summertime Arctic liquid-water clouds, airborne observations show that atmospheric aerosol particles 50 nm in diameter or smaller and most likely from natural sources are often involved in cloud formation in the pristine Arctic summer. The result expands the reference for aerosol forcing of climate. Further, for extremely low droplet concentrations, no evidence is found for a connection between cloud liquid water and aerosol particle concentrations.
Stefan Müller, Peter Hoor, Heiko Bozem, Ellen Gute, Bärbel Vogel, Andreas Zahn, Harald Bönisch, Timo Keber, Martina Krämer, Christian Rolf, Martin Riese, Hans Schlager, and Andreas Engel
Atmos. Chem. Phys., 16, 10573–10589, https://doi.org/10.5194/acp-16-10573-2016, https://doi.org/10.5194/acp-16-10573-2016, 2016
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In situ airborne measurements performed during TACTS/ESMVal 2012 were analysed to investigate the chemical compostion of the upper troposphere and lower stratosphere. N2O, CO and O3 data show an increase in tropospherically affected air masses within the extratropical stratosphere from August to September 2012, which originate from the Asian monsoon region. Thus, the Asian monsoon anticyclone significantly affected the chemical composition of the extratropical stratosphere during summer 2012.
Amir A. Aliabadi, Jennie L. Thomas, Andreas B. Herber, Ralf M. Staebler, W. Richard Leaitch, Hannes Schulz, Kathy S. Law, Louis Marelle, Julia Burkart, Megan D. Willis, Heiko Bozem, Peter M. Hoor, Franziska Köllner, Johannes Schneider, Maurice Levasseur, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 7899–7916, https://doi.org/10.5194/acp-16-7899-2016, https://doi.org/10.5194/acp-16-7899-2016, 2016
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For the first time, ship emissions of an ice-breaker, the Amundsen, is characterized while breaking ice in the Canadian Arctic using the plume intercepts by the Polar 6 aircraft. The study is novel, estimating lower plume expansion rates over the stable Arctic marine boundary layer and different emissions factors for oxides of nitrogen, black carbon, and carbon monoxide, compared to plume intercept studies in mid latitudes. These results can inform policy making and emission inventory datasets.
Megan D. Willis, Julia Burkart, Jennie L. Thomas, Franziska Köllner, Johannes Schneider, Heiko Bozem, Peter M. Hoor, Amir A. Aliabadi, Hannes Schulz, Andreas B. Herber, W. Richard Leaitch, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 7663–7679, https://doi.org/10.5194/acp-16-7663-2016, https://doi.org/10.5194/acp-16-7663-2016, 2016
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We present a case study focused on an aerosol growth event observed in the Canadian High Arctic during summer. Using measurements of aerosol chemical and physical properties we find evidence for aerosol growth into cloud condensation nuclei-active sizes, through marine-influenced secondary organic aerosol formation. Understanding the mechanisms that control the formation and growth of aerosol is crucial for our ability to predict cloud properties, and therefore radiative balance and climate.
Florian Berkes, Peter Hoor, Heiko Bozem, Daniel Kunkel, Michael Sprenger, and Stephan Henne
Atmos. Chem. Phys., 16, 6011–6025, https://doi.org/10.5194/acp-16-6011-2016, https://doi.org/10.5194/acp-16-6011-2016, 2016
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We presented airborne measurements of CO2 and O3 across the entrainment zone over a semi-remote environment in southwestern Germany in late summer 2011 .
For the first time CO2 and O3 were used as tracer to identify mixing through this transport barrier. We demonstrated that the tracer--tracer correlation of CO2 and O3 is a powerful tool to identify entrainment and mixing.
N. Sobanski, M. J. Tang, J. Thieser, G. Schuster, D. Pöhler, H. Fischer, W. Song, C. Sauvage, J. Williams, J. Fachinger, F. Berkes, P. Hoor, U. Platt, J. Lelieveld, and J. N. Crowley
Atmos. Chem. Phys., 16, 4867–4883, https://doi.org/10.5194/acp-16-4867-2016, https://doi.org/10.5194/acp-16-4867-2016, 2016
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The nitrate radical (NO3) is an important nocturnal oxidant. By measuring NO3, its precursors (nitrogen dioxide and ozone) and several trace gases with which it reacts, we examined the chemical and meteorological factors influencing the lifetime of NO3 at a semi-rural mountain site. Unexpectedly long lifetimes, approaching 1 h, were observed on several nights and were associated with a low-lying residual layer. We discuss the role of other reactions that convert NO2 to NO3.
N. I. Kristiansen, A. Stohl, D. J. L. Olivié, B. Croft, O. A. Søvde, H. Klein, T. Christoudias, D. Kunkel, S. J. Leadbetter, Y. H. Lee, K. Zhang, K. Tsigaridis, T. Bergman, N. Evangeliou, H. Wang, P.-L. Ma, R. C. Easter, P. J. Rasch, X. Liu, G. Pitari, G. Di Genova, S. Y. Zhao, Y. Balkanski, S. E. Bauer, G. S. Faluvegi, H. Kokkola, R. V. Martin, J. R. Pierce, M. Schulz, D. Shindell, H. Tost, and H. Zhang
Atmos. Chem. Phys., 16, 3525–3561, https://doi.org/10.5194/acp-16-3525-2016, https://doi.org/10.5194/acp-16-3525-2016, 2016
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Processes affecting aerosol removal from the atmosphere are not fully understood. In this study we investigate to what extent atmospheric transport models can reproduce observed loss of aerosols. We compare measurements of radioactive isotopes, that attached to ambient sulfate aerosols during the 2011 Fukushima nuclear accident, to 19 models using identical emissions. Results indicate aerosol removal that is too fast in most models, and apply to aerosols that have undergone long-range transport.
D. Kunkel, P. Hoor, and V. Wirth
Atmos. Chem. Phys., 16, 541–560, https://doi.org/10.5194/acp-16-541-2016, https://doi.org/10.5194/acp-16-541-2016, 2016
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By conducting various simulations of dry and moist baroclinic life cycles, we aimed to improve the understanding of whether dynamical or diabatic processes are more relevant to form a tropopause inversion layer at midlatitudes. Most importantly, our experiments highlighted the role of different moisture related processes for the formation and evolution of the tropopause inversion layer with varying relevance and strength in different phases of the baroclinic life cycles.
Christiane Hofmann, Astrid Kerkweg, Peter Hoor, and Patrick Jöckel
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2015-949, https://doi.org/10.5194/acp-2015-949, 2016
Revised manuscript not accepted
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Ozone enhancements at the surface, caused by descending stratospheric air masses along deep tropopause folds, can be reproduced using the model system MECO(n). It is shown that stratosphere-troposphere-exchange (STE) in the vicinity of a tropopause fold occurs in regions of turbulence and diabatic processes. The efficiency of mixing is quantified, showing that almost all of the air masses originating in the tropopause fold are transported into the troposphere during the following two days.
C. Rolf, A. Afchine, H. Bozem, B. Buchholz, V. Ebert, T. Guggenmoser, P. Hoor, P. Konopka, E. Kretschmer, S. Müller, H. Schlager, N. Spelten, O. Sumińska-Ebersoldt, J. Ungermann, A. Zahn, and M. Krämer
Atmos. Chem. Phys., 15, 9143–9158, https://doi.org/10.5194/acp-15-9143-2015, https://doi.org/10.5194/acp-15-9143-2015, 2015
W. Frey, R. Schofield, P. Hoor, D. Kunkel, F. Ravegnani, A. Ulanovsky, S. Viciani, F. D'Amato, and T. P. Lane
Atmos. Chem. Phys., 15, 6467–6486, https://doi.org/10.5194/acp-15-6467-2015, https://doi.org/10.5194/acp-15-6467-2015, 2015
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This study examines the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system, using the WRF model. Passive tracers are initialised to study the impact of the deep convection on the tracers and water vapour. We use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.
R. Pommrich, R. Müller, J.-U. Grooß, P. Konopka, F. Ploeger, B. Vogel, M. Tao, C. M. Hoppe, G. Günther, N. Spelten, L. Hoffmann, H.-C. Pumphrey, S. Viciani, F. D'Amato, C. M. Volk, P. Hoor, H. Schlager, and M. Riese
Geosci. Model Dev., 7, 2895–2916, 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.
B. Vogel, G. Günther, R. Müller, J.-U. Grooß, P. Hoor, M. Krämer, S. Müller, A. Zahn, and M. Riese
Atmos. Chem. Phys., 14, 12745–12762, https://doi.org/10.5194/acp-14-12745-2014, https://doi.org/10.5194/acp-14-12745-2014, 2014
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Enhanced tropospheric trace gases (e.g. pollutants) were measured in situ in
the lowermost stratosphere over Northern Europe on 26 September 2012
during the TACTS aircraft campaign. We found that the combination of rapid uplift by a typhoon and eastward eddy shedding from the Asian monsoon anticyclone is a novel fast transport pathway
that may carry boundary emissions from Southeast
Asia/western Pacific within approximately 5 weeks to the lowermost
stratosphere in Northern Europe.
M. Riese, H. Oelhaf, P. Preusse, J. Blank, M. Ern, F. Friedl-Vallon, H. Fischer, T. Guggenmoser, M. Höpfner, P. Hoor, M. Kaufmann, J. Orphal, F. Plöger, R. Spang, O. Suminska-Ebersoldt, J. Ungermann, B. Vogel, and W. Woiwode
Atmos. Meas. Tech., 7, 1915–1928, https://doi.org/10.5194/amt-7-1915-2014, https://doi.org/10.5194/amt-7-1915-2014, 2014
C. Liu, S. Beirle, T. Butler, P. Hoor, C. Frankenberg, P. Jöckel, M. Penning de Vries, U. Platt, A. Pozzer, M. G. Lawrence, J. Lelieveld, H. Tost, and T. Wagner
Atmos. Chem. Phys., 14, 1717–1732, https://doi.org/10.5194/acp-14-1717-2014, https://doi.org/10.5194/acp-14-1717-2014, 2014
J. Yoon, A. Pozzer, P. Hoor, D. Y. Chang, S. Beirle, T. Wagner, S. Schloegl, J. Lelieveld, and H. M. Worden
Atmos. Chem. Phys., 13, 11307–11316, https://doi.org/10.5194/acp-13-11307-2013, https://doi.org/10.5194/acp-13-11307-2013, 2013
D. Kunkel, H. Tost, and M. G. Lawrence
Atmos. Chem. Phys., 13, 4203–4222, https://doi.org/10.5194/acp-13-4203-2013, https://doi.org/10.5194/acp-13-4203-2013, 2013
J. Lelieveld, M. G. Lawrence, and D. Kunkel
Atmos. Chem. Phys., 13, 31–34, https://doi.org/10.5194/acp-13-31-2013, https://doi.org/10.5194/acp-13-31-2013, 2013
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Moritz Deinhard and Christian M. Grams
Weather Clim. Dynam., 5, 927–942, https://doi.org/10.5194/wcd-5-927-2024, https://doi.org/10.5194/wcd-5-927-2024, 2024
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Stochastic perturbations are an established technique to represent model uncertainties in numerical weather prediction. While such schemes are beneficial for the forecast skill, they can also change the mean state of the model. We analyse how different schemes modulate rapidly ascending airstreams and whether the changes to such weather systems are projected onto larger scales. We thereby provide a process-oriented perspective on how perturbations affect the model climate.
Henri Rossi Pinheiro, Kevin Ivan Hodges, and Manoel Alonso Gan
Weather Clim. Dynam., 5, 881–894, https://doi.org/10.5194/wcd-5-881-2024, https://doi.org/10.5194/wcd-5-881-2024, 2024
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Cut-off lows (COLs) are weather systems with varied structures and lifecycles, from upper atmospheric to deep vortices. Deep, strong COLs are common around Australia and the southwestern Pacific in autumn and spring, while shallow, weak COLs occur more in summer near the Equator. Jet streams play a crucial role in COL development, with different jets influencing its depth and strength. The study also emphasizes the need for better representation of diabatic processes in reanalysis data.
Aleksa Stanković, Gabriele Messori, Joaquim G. Pinto, and Rodrigo Caballero
Weather Clim. Dynam., 5, 821–837, https://doi.org/10.5194/wcd-5-821-2024, https://doi.org/10.5194/wcd-5-821-2024, 2024
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The article studies extreme winds near the surface over the North Atlantic Ocean. These winds are caused by storms that pass through this region. The strongest storms that have occurred in the winters from 1950–2020 are studied in detail and compared to weaker but still strong storms. The analysis shows that the storms associated with the strongest winds are preceded by another older storm that travelled through the same region and made the conditions suitable for development of extreme winds.
Edward Groot, Patrick Kuntze, Annette Miltenberger, and Holger Tost
Weather Clim. Dynam., 5, 779–803, https://doi.org/10.5194/wcd-5-779-2024, https://doi.org/10.5194/wcd-5-779-2024, 2024
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Deep convective clouds (thunderstorms), which may cause severe weather, tend to coherently organise into structured cloud systems. Accurate representation of these systems in models is difficult due to their complex dynamics and, in numerical simulations, the dependence of their dynamics on resolution. Here, the effect of convective organisation and geometry on their outflow winds (altitudes of 7–14 km) is investigated. Representation of their dynamics and outflows improves at higher resolution.
Stephen Outten and Richard Davy
Weather Clim. Dynam., 5, 753–762, https://doi.org/10.5194/wcd-5-753-2024, https://doi.org/10.5194/wcd-5-753-2024, 2024
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The North Atlantic Oscillation is linked to wintertime weather events over Europe. One feature often overlooked is how much the climate variability explained by the NAO has changed over time. We show that there has been a considerable increase in the percentage variance explained by the NAO over the 20th century and that this is not reproduced by 50 CMIP6 climate models, which are generally biased too high. This has implications for projections and prediction of weather events in the region.
Seraphine Hauser, Franziska Teubler, Michael Riemer, Peter Knippertz, and Christian M. Grams
Weather Clim. Dynam., 5, 633–658, https://doi.org/10.5194/wcd-5-633-2024, https://doi.org/10.5194/wcd-5-633-2024, 2024
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Blocking over Greenland has substantial impacts on the weather and climate in mid- and high latitudes. This study applies a quasi-Lagrangian thinking on the dynamics of Greenland blocking and reveals two pathways of anticyclonic anomalies linked to the block. Moist processes were found to play a dominant role in the formation and maintenance of blocking. This emphasizes the necessity of the correct representation of moist processes in weather and climate models to realistically depict blocking.
Katharina Heitmann, Michael Sprenger, Hanin Binder, Heini Wernli, and Hanna Joos
Weather Clim. Dynam., 5, 537–557, https://doi.org/10.5194/wcd-5-537-2024, https://doi.org/10.5194/wcd-5-537-2024, 2024
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Warm conveyor belts (WCBs) are coherently ascending air streams that occur in extratropical cyclones where they form precipitation and often affect the large-scale flow. We quantified the key characteristics and impacts of WCBs and linked them to different phases in the cyclone life cycle and to different WCB branches. A climatology of these metrics revealed that WCBs are most intense during cyclone intensification and that the cyclonic and anticyclonic WCB branches show distinct differences.
Dor Sandler, Hadas Saaroni, Baruch Ziv, Talia Tamarin-Brodsky, and Nili Harnik
EGUsphere, https://doi.org/10.5194/egusphere-2024-1054, https://doi.org/10.5194/egusphere-2024-1054, 2024
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The North Atlantic region serves as a source of moisture and energy for Mediterranean storms. Its impact over the Levant region remains an open question due to its smaller weather systems and their longer distance from the ocean. We find an optimal circulation pattern which allows North Atlantic influence to reach farther into the Eastern Mediterranean, thus making storms stronger and rainier. This may be relevant for future Mediterranean climate, which is projected to become much drier.
Konstantin Krüger, Andreas Schäfler, Martin Weissmann, and George C. Craig
Weather Clim. Dynam., 5, 491–509, https://doi.org/10.5194/wcd-5-491-2024, https://doi.org/10.5194/wcd-5-491-2024, 2024
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Initial conditions of current numerical weather prediction models insufficiently represent the sharp vertical gradients across the midlatitude tropopause. Observation-space data assimilation output is used to study the influence of assimilated radiosondes on the tropopause. The radiosondes reduce systematic biases of the model background and sharpen temperature and wind gradients in the analysis. Tropopause sharpness is still underestimated in the analysis, which may impact weather forecasts.
Lucas Fery and Davide Faranda
Weather Clim. Dynam., 5, 439–461, https://doi.org/10.5194/wcd-5-439-2024, https://doi.org/10.5194/wcd-5-439-2024, 2024
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In this study, we analyse warm-season derechos – a type of severe convective windstorm – in France between 2000 and 2022, identifying 38 events. We compare their frequency and features with other countries. We also examine changes in the associated large-scale patterns. We find that convective instability has increased in southern Europe. However, the attribution of these changes to natural climate variability, human-induced climate change or a combination of both remains unclear.
Lukas Jansing, Lukas Papritz, and Michael Sprenger
Weather Clim. Dynam., 5, 463–489, https://doi.org/10.5194/wcd-5-463-2024, https://doi.org/10.5194/wcd-5-463-2024, 2024
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Using an innovative approach, the descent of foehn is diagnosed from a Lagrangian perspective based on 15 kilometer-scale simulations combined with online trajectories. The descent is confined to distinct hotspots in the immediate lee of local mountain peaks and chains. Two detailed case studies reveal a varying wave regime to be associated with the descent. Furthermore, additional controlling factors, such as the diurnal cycle, likewise influence the descent activity.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 419–438, https://doi.org/10.5194/wcd-5-419-2024, https://doi.org/10.5194/wcd-5-419-2024, 2024
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We show that the formation of Mediterranean cyclones follows the presence of cyclones over the North Atlantic. The distinct regions of cyclone activity in the Mediterranean in the different seasons can be linked to the atmospheric state, in particular the position of the polar jet over the North Atlantic. With this we now better understand the processes that lead to the formation of Mediterranean cyclones. We used a novel simulation framework in which we directly show and probe this connection.
Belinda Hotz, Lukas Papritz, and Matthias Röthlisberger
Weather Clim. Dynam., 5, 323–343, https://doi.org/10.5194/wcd-5-323-2024, https://doi.org/10.5194/wcd-5-323-2024, 2024
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Analysing the vertical structure of temperature anomalies of recent record-breaking heatwaves reveals a complex four-dimensional interplay of anticyclone–heatwave interactions, with vertically strongly varying advective, adiabatic, and diabatic contributions to the respective temperature anomalies. The heatwaves featured bottom-heavy positive temperature anomalies, extending throughout the troposphere.
Alexandre Tuel and Olivia Martius
Weather Clim. Dynam., 5, 263–292, https://doi.org/10.5194/wcd-5-263-2024, https://doi.org/10.5194/wcd-5-263-2024, 2024
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Warm and cold spells often have damaging consequences for agriculture, power demand, human health and infrastructure, especially when they occur over large areas and persist for a week or more. Here, we split the Northern Hemisphere extratropics into coherent regions where 3-week warm and cold spells in winter and summer are associated with the same large-scale circulation patterns. To understand their physical drivers, we analyse the associated circulation and temperature budget anomalies.
Jacob Perez, Amanda Maycock, Stephen Griffiths, Steven Hardiman, and Christine McKenna
EGUsphere, https://doi.org/10.5194/egusphere-2024-318, https://doi.org/10.5194/egusphere-2024-318, 2024
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This study assesses existing methods for identifying the position and tilt of the North Atlantic eddy-driven jet, proposing a new feature-based approach. The new method overcomes limitations of other methods, offering a more robust characterization. Contrary to prior findings, the distribution of daily latitudes shows no distinct multi-modal structure, challenging the notion of preferred jet stream latitudes or regimes. This research enhances our understanding of North Atlantic dynamics.
Marta Wenta, Christian M. Grams, Lukas Papritz, and Marc Federer
Weather Clim. Dynam., 5, 181–209, https://doi.org/10.5194/wcd-5-181-2024, https://doi.org/10.5194/wcd-5-181-2024, 2024
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Our study links air–sea interactions over the Gulf Stream to an atmospheric block in February 2019. We found that over 23 % of air masses that were lifted into the block by cyclones interacted with the Gulf Stream. As cyclones pass over the Gulf Stream, they cause intense surface evaporation events, preconditioning the environment for the development of cyclones. This implies that air–sea interactions over the Gulf Stream affect the large-scale dynamics in the North Atlantic–European region.
Alice Portal, Shira Raveh-Rubin, Jennifer L. Catto, Yonatan Givon, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2024-270, https://doi.org/10.5194/egusphere-2024-270, 2024
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Mediterranean cyclones are associated with extended rain, wind and wave impacts. Although beneficial for regional water resources, their passage may induce extreme weather, which is specially impactful when multiple hazards combine together. Here we show how the passage of Mediterranean cyclones increases the likelihood of rain-wind and wave-wind compounding, and how compound-cyclone statistics varies by region and season, but also depends on the presence of specific airflows around the cyclone.
Yonatan Givon, Or Hess, Emmanouil Flaounas, Jennifer Louise Catto, Michael Sprenger, and Shira Raveh-Rubin
Weather Clim. Dynam., 5, 133–162, https://doi.org/10.5194/wcd-5-133-2024, https://doi.org/10.5194/wcd-5-133-2024, 2024
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A novel classification of Mediterranean cyclones is presented, enabling a separation between storms driven by different atmospheric processes. The surface impact of each cyclone class differs greatly by precipitation, winds, and temperatures, providing an invaluable tool to study the climatology of different types of Mediterranean storms and enhancing the understanding of their predictability, on both weather and climate scales.
Talia Tamarin-Brodsky and Nili Harnik
Weather Clim. Dynam., 5, 87–108, https://doi.org/10.5194/wcd-5-87-2024, https://doi.org/10.5194/wcd-5-87-2024, 2024
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Synoptic waves in the atmosphere tend to follow a typical Rossby wave lifecycle, involving a linear growth stage followed by nonlinear and irreversible Rossby wave breaking (RWB). Here we take a new approach to study RWB events and their fundamental relation to weather systems by combining a storm-tracking technique and an RWB detection algorithm. The synoptic-scale dynamics leading to RWB is then examined by analyzing time evolution composites of cyclones and anticyclones during RWB events.
Sebastian Schemm and Matthias Röthlisberger
Weather Clim. Dynam., 5, 43–63, https://doi.org/10.5194/wcd-5-43-2024, https://doi.org/10.5194/wcd-5-43-2024, 2024
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Climate change has started to weaken atmospheric circulation during summer in the Northern Hemisphere. However, there is low agreement on the processes underlying changes in, for example, the stationarity of weather patterns or the seasonality of the jet response to warming. This study examines changes during summertime in an idealised setting and confirms some important changes in hemisphere-wide wave and jet characteristics under warming.
Patrick Martineau, Swadhin K. Behera, Masami Nonaka, Hisashi Nakamura, and Yu Kosaka
Weather Clim. Dynam., 5, 1–15, https://doi.org/10.5194/wcd-5-1-2024, https://doi.org/10.5194/wcd-5-1-2024, 2024
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The representation of subweekly near-surface temperature variability trends over the Southern Hemisphere landmasses is compared across multiple atmospheric reanalyses. It is found that there is generally a good agreement concerning the positive trends affecting South Africa and Australia in the spring, and South America in the summer. A more efficient generation of subweekly temperature variance by horizontal temperature fluxes contributes to the observed rise.
Lea Eisenstein, Benedikt Schulz, Joaquim G. Pinto, and Peter Knippertz
Weather Clim. Dynam., 4, 981–999, https://doi.org/10.5194/wcd-4-981-2023, https://doi.org/10.5194/wcd-4-981-2023, 2023
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Mesoscale high-wind features within extratropical cyclones can cause immense damage. In Part 1 of this work, we introduced RAMEFI (RAndom-forest-based MEsoscale wind Feature Identification), an objective, flexible identification tool for these wind features based on a probabilistic random forest. Here, we use RAMEFI to compile a climatology of the features over 19 extended winter seasons over western and central Europe, focusing on relative occurrence, affected areas and further characteristics.
Tiina Nygård, Lukas Papritz, Tuomas Naakka, and Timo Vihma
Weather Clim. Dynam., 4, 943–961, https://doi.org/10.5194/wcd-4-943-2023, https://doi.org/10.5194/wcd-4-943-2023, 2023
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Despite the general warming trend, wintertime cold-air outbreaks in Europe have remained nearly as extreme and as common as decades ago. In this study, we identify six principal cold anomaly types over Europe in 1979–2020. We show the origins of various physical processes and their contributions to the formation of cold wintertime air masses.
Andrea Marcheggiani and Thomas Spengler
Weather Clim. Dynam., 4, 927–942, https://doi.org/10.5194/wcd-4-927-2023, https://doi.org/10.5194/wcd-4-927-2023, 2023
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There is a gap between the theoretical understanding and model representation of moist diabatic effects on the evolution of storm tracks. We seek to bridge this gap by exploring the relationship between diabatic and adiabatic contributions to changes in baroclinicity. We find reversed behaviours in the lower and upper troposphere in the maintenance of baroclinicity. In particular, our study reveals a link between higher moisture availability and upper-tropospheric restoration of baroclinicity.
Raphaël Rousseau-Rizzi, Shira Raveh-Rubin, Jennifer Catto, Alice Portal, Yonatan Givon, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2023-2322, https://doi.org/10.5194/egusphere-2023-2322, 2023
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We aim to identify the situations when rain and wind, rain and wave, or heat and dust hazards co-occur within cyclones in the Mediterranean. These poorly understood hazard combinations respectively enhance the risk to infrastructure, the risk of coastal flooding, and the risk of respiratory issues. We identify distinct weather configurations and distinct cyclone structures, which favor distinct co-occurrence combinations. This has implications for the forecasting of these hazards.
Alice Portal, Fabio D'Andrea, Paolo Davini, Mostafa E. Hamouda, and Claudia Pasquero
Weather Clim. Dynam., 4, 809–822, https://doi.org/10.5194/wcd-4-809-2023, https://doi.org/10.5194/wcd-4-809-2023, 2023
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The differences between climate models can be exploited to infer how specific aspects of the climate influence the Earth system. This work analyses the effects of a negative temperature anomaly over the Tibetan Plateau on the winter atmospheric circulation. We show that models with a colder-than-average Tibetan Plateau present a reinforcement of the eastern Asian winter monsoon and discuss the atmospheric response to the enhanced transport of cold air from the continent toward the Pacific Ocean.
Charlie C. Suitters, Oscar Martínez-Alvarado, Kevin I. Hodges, Reinhard K. H. Schiemann, and Duncan Ackerley
Weather Clim. Dynam., 4, 683–700, https://doi.org/10.5194/wcd-4-683-2023, https://doi.org/10.5194/wcd-4-683-2023, 2023
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Atmospheric blocking describes large and persistent high surface pressure. In this study, the relationship between block persistence and smaller-scale systems is examined. Persistent blocks result from more interactions with small systems, but a block's persistence does not depend as strongly on the strength of these smaller features. This work is important because it provides more knowledge as to how blocks can be allowed to persist, which is something we still do not fully understand.
Emmanouil Flaounas, Leonardo Aragão, Lisa Bernini, Stavros Dafis, Benjamin Doiteau, Helena Flocas, Suzanne L. Gray, Alexia Karwat, John Kouroutzoglou, Piero Lionello, Mario Marcello Miglietta, Florian Pantillon, Claudia Pasquero, Platon Patlakas, María Ángeles Picornell, Federico Porcù, Matthew D. K. Priestley, Marco Reale, Malcolm J. Roberts, Hadas Saaroni, Dor Sandler, Enrico Scoccimarro, Michael Sprenger, and Baruch Ziv
Weather Clim. Dynam., 4, 639–661, https://doi.org/10.5194/wcd-4-639-2023, https://doi.org/10.5194/wcd-4-639-2023, 2023
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Cyclone detection and tracking methods (CDTMs) have different approaches in defining and tracking cyclone centers. This leads to disagreements on extratropical cyclone climatologies. We present a new approach that combines tracks from individual CDTMs to produce new composite tracks. These new tracks are shown to correspond to physically meaningful systems with distinctive life stages.
Deborah Morgenstern, Isabell Stucke, Georg J. Mayr, Achim Zeileis, and Thorsten Simon
Weather Clim. Dynam., 4, 489–509, https://doi.org/10.5194/wcd-4-489-2023, https://doi.org/10.5194/wcd-4-489-2023, 2023
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Two thunderstorm environments are described for Europe: mass-field thunderstorms, which occur mostly in summer, over land, and under similar meteorological conditions, and wind-field thunderstorms, which occur mostly in winter, over the sea, and under more diverse meteorological conditions. Our descriptions are independent of static thresholds and help to understand why thunderstorms in unfavorable seasons for lightning pose a particular risk to tall infrastructure such as wind turbines.
Florian Ruff and Stephan Pfahl
Weather Clim. Dynam., 4, 427–447, https://doi.org/10.5194/wcd-4-427-2023, https://doi.org/10.5194/wcd-4-427-2023, 2023
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In this study, we analyse the generic atmospheric processes of very extreme, 100-year precipitation events in large central European river catchments and the corresponding differences to less extreme events, based on a large time series (~1200 years) of simulated but realistic daily precipitation events from the ECMWF. Depending on the catchment, either dynamical mechanisms or thermodynamic conditions or a combination of both distinguish 100-year events from less extreme precipitation events.
Seraphine Hauser, Franziska Teubler, Michael Riemer, Peter Knippertz, and Christian M. Grams
Weather Clim. Dynam., 4, 399–425, https://doi.org/10.5194/wcd-4-399-2023, https://doi.org/10.5194/wcd-4-399-2023, 2023
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Blocking describes a flow configuration in the midlatitudes where stationary high-pressure systems block the propagation of weather systems. This study combines three individual perspectives that capture the dynamics and importance of various processes in the formation of a major blocking in 2016 from a weather regime perspective. In future work, this framework will enable a holistic view of the dynamics and the role of moist processes in different life cycle stages of blocked weather regimes.
Charles G. Gertler, Paul A. O'Gorman, and Stephan Pfahl
Weather Clim. Dynam., 4, 361–379, https://doi.org/10.5194/wcd-4-361-2023, https://doi.org/10.5194/wcd-4-361-2023, 2023
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The relationship between the time-mean state of the atmosphere and aspects of atmospheric circulation drives general understanding of the atmospheric circulation. Here, we present new techniques to calculate local properties of the time-mean atmosphere and relate those properties to aspects of extratropical circulation with important implications for weather. This relationship should help connect changes to the atmosphere, such as under global warming, to changes in midlatitude weather.
Colin Manning, Martin Widmann, Douglas Maraun, Anne F. Van Loon, and Emanuele Bevacqua
Weather Clim. Dynam., 4, 309–329, https://doi.org/10.5194/wcd-4-309-2023, https://doi.org/10.5194/wcd-4-309-2023, 2023
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Climate models differ in their representation of dry spells and high temperatures, linked to errors in the simulation of persistent large-scale anticyclones. Models that simulate more persistent anticyclones simulate longer and hotter dry spells, and vice versa. This information is important to consider when assessing the likelihood of such events in current and future climate simulations so that we can assess the plausibility of their future projections.
Franziska Teubler, Michael Riemer, Christopher Polster, Christian M. Grams, Seraphine Hauser, and Volkmar Wirth
Weather Clim. Dynam., 4, 265–285, https://doi.org/10.5194/wcd-4-265-2023, https://doi.org/10.5194/wcd-4-265-2023, 2023
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Weather regimes govern an important part of the sub-seasonal variability of the mid-latitude circulation. The year-round dynamics of blocked regimes in the Atlantic European region are investigated in over 40 years of data. We show that the dynamics between the regimes are on average very similar. Within the regimes, the main variability – starting from the characteristics of dynamical processes alone – dominates and transcends the variability in season and types of transitions.
Antonio Segalini, Jacopo Riboldi, Volkmar Wirth, and Gabriele Messori
EGUsphere, https://doi.org/10.5194/egusphere-2023-316, https://doi.org/10.5194/egusphere-2023-316, 2023
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Planetary Rossby waves are created by topography and evolve in time. In this work, an analytical solution of this classical problem is proposed under the approximation of linear wave dynamics. The theory is able to describe reasonably well the evolution of the perturbation and compares well with full nonlinear simulations. Several relevant cases with single and double zonal jets are assessed with the theoretical framework
Acacia S. Pepler and Irina Rudeva
Weather Clim. Dynam., 4, 175–188, https://doi.org/10.5194/wcd-4-175-2023, https://doi.org/10.5194/wcd-4-175-2023, 2023
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In recent decades, cold fronts have rained less often in southeast Australia, which contributes to decreasing cool season rainfall. The largest changes in front dynamics are found to the north of the area where rain changes. Wet fronts have strong westerly winds that reach much further north than dry fronts do, and these fronts are becoming less common, linked to weakening subtropical winds and changes in the Southern Hemisphere circulation.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 4, 157–173, https://doi.org/10.5194/wcd-4-157-2023, https://doi.org/10.5194/wcd-4-157-2023, 2023
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We investigate the dynamical origin of the lower-atmospheric potential vorticity (PV; linked to the intensity of cyclones) in Mediterranean cyclones. We quantify the contribution of the cyclone and the environment by tracing PV backward in time and space and linking it to the track of the cyclone. We find that the lower-tropospheric PV is produced shortly before the cyclone's stage of highest intensity. We investigate the driving processes and use a global dataset and a process-resolving one.
Felix Jäger, Philip Rupp, and Thomas Birner
Weather Clim. Dynam., 4, 49–60, https://doi.org/10.5194/wcd-4-49-2023, https://doi.org/10.5194/wcd-4-49-2023, 2023
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Mid-latitude weather is dominated by the growth, breaking and decay of baroclinic waves and associated jet shifts. A way to study this process is via idealised life-cycle simulations, which are often classified as LC1 (anticyclonic breaking, poleward shift) or LC2 (cyclonic breaking, equatorward shift), depending on details of the initial state. We show that all systems exhibit predominantly anticyclonic character and poleward net shifts if multiple wave modes are allowed to grow simultaneously.
Philipp Breul, Paulo Ceppi, and Theodore G. Shepherd
Weather Clim. Dynam., 4, 39–47, https://doi.org/10.5194/wcd-4-39-2023, https://doi.org/10.5194/wcd-4-39-2023, 2023
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Accurately predicting the response of the midlatitude jet stream to climate change is very important, but models show a variety of possible scenarios. Previous work identified a relationship between climatological jet latitude and future jet shift in the southern hemispheric winter. We show that the relationship does not hold in separate sectors and propose that zonal asymmetries are the ultimate cause in the zonal mean. This questions the usefulness of the relationship.
Patrick Johannes Stoll, Rune Grand Graversen, and Gabriele Messori
Weather Clim. Dynam., 4, 1–17, https://doi.org/10.5194/wcd-4-1-2023, https://doi.org/10.5194/wcd-4-1-2023, 2023
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The atmosphere is in motion and hereby transporting warm, cold, moist, and dry air to different climate zones. In this study, we investigate how this transport of energy organises in different manners. Outside the tropics, atmospheric waves of sizes between 2000 and 8000 km, which we perceive as cyclones from the surface, transport most of the energy and moisture poleward. In the winter, large-scale weather situations become very important for transporting energy into the polar regions.
Lisa Schielicke and Stephan Pfahl
Weather Clim. Dynam., 3, 1439–1459, https://doi.org/10.5194/wcd-3-1439-2022, https://doi.org/10.5194/wcd-3-1439-2022, 2022
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Projected future heatwaves in many European regions will be even warmer than the mean increase in summer temperature suggests. To identify the underlying thermodynamic and dynamic processes, we compare Lagrangian backward trajectories of airstreams associated with heatwaves in two time slices (1991–2000 and 2091–2100) in a large single-model ensemble (CEMS-LE). We find stronger future descent associated with adiabatic warming in some regions and increased future diabatic heating in most regions.
Iana Strigunova, Richard Blender, Frank Lunkeit, and Nedjeljka Žagar
Weather Clim. Dynam., 3, 1399–1414, https://doi.org/10.5194/wcd-3-1399-2022, https://doi.org/10.5194/wcd-3-1399-2022, 2022
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We show that the Eurasian heat waves (HWs) have signatures in the global circulation. We present changes in the probability density functions (PDFs) of energy anomalies in the zonal-mean state and in the Rossby waves at different zonal scales in relation to the changes in intramonthly variability. The skewness of the PDF of planetary-scale Rossby waves is shown to increase during HWs, while their intramonthly variability is reduced, a process referred to as blocking.
Anubhav Choudhary and Aiko Voigt
Weather Clim. Dynam., 3, 1199–1214, https://doi.org/10.5194/wcd-3-1199-2022, https://doi.org/10.5194/wcd-3-1199-2022, 2022
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The warm conveyor belt (WCB), which is a stream of coherently rising air parcels, is an important feature of extratropical cyclones. This work presents the impact of model grid spacing on simulation of cloud diabatic processes in the WCB of a North Atlantic cyclone. We find that the refinement of the model grid systematically enhances the dynamical properties and heat releasing processes within the WCB. However, this pattern does not have a strong impact on the strength of associated cyclones.
S. Mubashshir Ali, Matthias Röthlisberger, Tess Parker, Kai Kornhuber, and Olivia Martius
Weather Clim. Dynam., 3, 1139–1156, https://doi.org/10.5194/wcd-3-1139-2022, https://doi.org/10.5194/wcd-3-1139-2022, 2022
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Persistent weather can lead to extreme weather conditions. One such atmospheric flow pattern, termed recurrent Rossby wave packets (RRWPs), has been shown to increase persistent weather in the Northern Hemisphere. Here, we show that RRWPs are also an important feature in the Southern Hemisphere. We evaluate the role of RRWPs during south-eastern Australian heatwaves and find that they help to persist the heatwaves by forming upper-level high-pressure systems over south-eastern Australia.
Lea Eisenstein, Benedikt Schulz, Ghulam A. Qadir, Joaquim G. Pinto, and Peter Knippertz
Weather Clim. Dynam., 3, 1157–1182, https://doi.org/10.5194/wcd-3-1157-2022, https://doi.org/10.5194/wcd-3-1157-2022, 2022
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Mesoscale high-wind features within extratropical cyclones can cause immense damage. Here, we present RAMEFI, a novel approach to objectively identify the wind features based on a probabilistic random forest. RAMEFI enables a wide range of applications such as probabilistic predictions for the occurrence or a multi-decadal climatology of these features, which will be the focus of Part 2 of the study, with the goal of improving wind and, specifically, wind gust forecasts in the long run.
Lukas Jansing, Lukas Papritz, Bruno Dürr, Daniel Gerstgrasser, and Michael Sprenger
Weather Clim. Dynam., 3, 1113–1138, https://doi.org/10.5194/wcd-3-1113-2022, https://doi.org/10.5194/wcd-3-1113-2022, 2022
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This study presents a 5-year climatology of three main foehn types and three deep-foehn subtypes. The main types differ in their large-scale and Alpine-scale weather conditions and the subtypes in terms of the amount and extent of precipitation on the Alpine south side. The different types of foehn are found to strongly affect the local meteorological conditions at Altdorf. The study concludes by setting the new classification into a historic context.
Valerio Lembo, Federico Fabiano, Vera Melinda Galfi, Rune Grand Graversen, Valerio Lucarini, and Gabriele Messori
Weather Clim. Dynam., 3, 1037–1062, https://doi.org/10.5194/wcd-3-1037-2022, https://doi.org/10.5194/wcd-3-1037-2022, 2022
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Eddies in mid-latitudes characterize the exchange of heat between the tropics and the poles. This exchange is largely uneven, with a few extreme events bearing most of the heat transported across latitudes in a season. It is thus important to understand what the dynamical mechanisms are behind these events. Here, we identify recurrent weather regime patterns associated with extreme transports, and we identify scales of mid-latitudinal eddies that are mostly responsible for the transport.
Fei Luo, Frank Selten, Kathrin Wehrli, Kai Kornhuber, Philippe Le Sager, Wilhelm May, Thomas Reerink, Sonia I. Seneviratne, Hideo Shiogama, Daisuke Tokuda, Hyungjun Kim, and Dim Coumou
Weather Clim. Dynam., 3, 905–935, https://doi.org/10.5194/wcd-3-905-2022, https://doi.org/10.5194/wcd-3-905-2022, 2022
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Recent studies have identified the weather systems in observational data, where wave patterns with high-magnitude values that circle around the whole globe in either wavenumber 5 or wavenumber 7 are responsible for the extreme events. In conclusion, we find that the climate models are able to reproduce the large-scale atmospheric circulation patterns as well as their associated surface variables such as temperature, precipitation, and sea level pressure.
Meryl Wimmer, Gwendal Rivière, Philippe Arbogast, Jean-Marcel Piriou, Julien Delanoë, Carole Labadie, Quitterie Cazenave, and Jacques Pelon
Weather Clim. Dynam., 3, 863–882, https://doi.org/10.5194/wcd-3-863-2022, https://doi.org/10.5194/wcd-3-863-2022, 2022
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The effect of deep convection representation on the jet stream above the cold front of an extratropical cyclone is investigated in the global numerical weather prediction model ARPEGE. Two simulations using different deep convection schemes are compared with (re)analysis datasets and NAWDEX airborne observations. A deeper jet stream is observed with the less active scheme. The diabatic origin of this difference is interpreted by backward Lagrangian trajectories and potential vorticity budgets.
Matthias Röthlisberger, Barbara Scherrer, Andries Jan de Vries, and Raphael Portmann
Weather Clim. Dynam., 3, 733–754, https://doi.org/10.5194/wcd-3-733-2022, https://doi.org/10.5194/wcd-3-733-2022, 2022
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We examine the palette of synoptic storylines accompanying unusually long wet spells in Europe. Thereby, we identify a hitherto not documented mechanism for generating long wet spells which involves recurrent Rossby wave breaking and subsequent cutoff replenishment. Understanding the synoptic processes behind long wet spells is relevant in light of projected changes in wet spell characteristics as it is a prerequisite for evaluating climate models with regard to such events.
Cited articles
Bense, V.: Modifikation von Schwerewellen bei Propagation durch die Tropopause
– Idealisierte Modellstudien, Dissertation, Johannes Gutenberg-University
Mainz, https://doi.org/10.25358/openscience-2356, 2019. a, b
Berthet, G., Esler, J. G., and Haynes, P. H.: A Lagrangian perspective of the
tropopause and the ventilation of the lowermost stratosphere, J. Geophys.
Res.-Atmos., 112, 1–14, https://doi.org/10.1029/2006JD008295, 2007. a
ECMWF: IFS documentation – Cy41r2 Operational implementation 8 March 2016
Part III: Dynamics and numerical procedures, in: IFS Documentation CY41R2,
ECMWF, https://doi.org/10.21957/83wouv80, 2016. a
Ellrod, G. P. and Knapp, D. I.: An Objective Clear-Air Turbulence Forecasting
Technique: Verification and Operational Use, Weather Forecast., 7, 15,
https://doi.org/10.1175/1520-0434(1992)007<0150:AOCATF>2.0.CO;2, 1992. a
Endlich, R. M. and McLean, G. S.: Jet-Stream Structure over the Central United
States Determined from Aircraft Observations, J. Appl. Meteorol. Clim., 4,
83–90, https://doi.org/10.1175/1520-0450(1965)004<0083:jssotc>2.0.co;2, 1965. a
Ertel, H.: Ein neuer hydrodynamischer Erhaltungssatz, Die
Naturwissenschaften, 30, 543–544, https://doi.org/10.1007/BF01475602, 1942. a
European Centre for Medium Range Weather Forecasts: ERA5, available at:
https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5, last access: 21 July 2021. a
Forster, P. and Shine, K. P.: Radiative forcing and temperature trends from
stratospheric ozone changes, J. Geophys. Res.-Atmos., 102, 10841–10855,
https://doi.org/10.1029/96JD03510, 1997. a
Fritts, D. C., Wang, L., and Werne, J. A.: Gravity wave-fine structure
interactions. Part I: Influences of fine structure form and orientation on
flow evolution and instability, J. Atmos. Sci., 70, 3710–3734,
https://doi.org/10.1175/JAS-D-13-055.1, 2013. a
Fritts, D. C., Wang, L., Geller, M. A., Lawrence, D. A., Werne, J., and
Balsley, B. B.: Numerical modeling of multiscale dynamics at a high reynolds
number: Instabilities, turbulence, and an assessment of ozmidov and thorpe
scales, J. Atmos. Sci., 73, 555–578, https://doi.org/10.1175/JAS-D-14-0343.1, 2016. a
Fritts, D. C., Wang, L., Baumgarten, G., Miller, A. D., Geller, M. A., Jones,
G., Limon, M., Chapman, D., Didier, J., Kjellstrand, C. B., Araujo, D.,
Hillbrand, S., Korotkov, A., Tucker, G., and Vinokurov, J.: High-resolution
observations and modeling of turbulence sources, structures, and intensities
in the upper mesosphere, J. Atmos. Sol.-Terr. Phys., 162, 57–78,
https://doi.org/10.1016/j.jastp.2016.11.006, 2017. a
Fueglistaler, S., Dessler, A. E., Dunkerton, T. J., Folkins, I., Fu, Q., and
Mote, P. W.: Tropical Tropopause Layer, Rev. Geophys., 47, 1–31,
https://doi.org/10.1029/2008RG000267, 2009. a
Gettelman, A. and Wang, T.: Structural diagnostics of the tropopause inversion
layer and its evolution, J. Geophys. Res.-Atmos., 120, 46–62,
https://doi.org/10.1002/2014JD021846, 2015. a
Grise, K. M., Thompson, D. W., and Birner, T.: A global survey of static
stability in the stratosphere and upper troposphere, J. Climate, 23,
2275–2292, https://doi.org/10.1175/2009JCLI3369.1, 2010. a
Hegglin, M. I., Boone, C. D., Manney, G. L., and Walker, K. A.: A global view
of the extratropical tropopause transition layer from Atmospheric Chemistry
Experiment Fourier Transform Spectrometer O3, H2O, and CO, J. Geophys.
Res.-Atmos., 114, 1–18, https://doi.org/10.1029/2008JD009984, 2009. a
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A.,
Muñoz-Sabater, J., 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. J., 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. R. Meteorol. Soc., 146, 1999–2049,
https://doi.org/10.1002/qj.3803, 2020. a, b
Hoffmann, L., Günther, G., Li, D., Stein, O., Wu, X., Griessbach, S., Heng, Y., Konopka, P., Müller, R., Vogel, B., and Wright, J. S.: From ERA-Interim to ERA5: the considerable impact of ECMWF's next-generation reanalysis on Lagrangian transport simulations, Atmos. Chem. Phys., 19, 3097–3124, https://doi.org/10.5194/acp-19-3097-2019, 2019. a, b
Holton, J. R.: Stratosphere-Troposphere Exchange, Stratosphere Troposphere
Interactions, Springer, Dordrecht, pp. 331–355, https://doi.org/10.1007/978-1-4020-8217-7_8, 1995. a, b, c
Homeyer, C. R., Pan, L. L., Dorsi, S. W., Avallone, L. M., Weinheimer, A. J.,
O'Brien, A. S., Digangi, J. P., Zondlo, M. A., Ryerson, T. B., Diskin, G. S.,
and Campos, T. L.: Convective transport of water vapor into the lower
stratosphere observed during double-tropopause events, J. Geophys.
Res.-Atmos., 119, 10941–10958, https://doi.org/10.1002/2014JD021485, 2014. a
Hoor, P., Fischer, H., Lange, L., Lelieveld, J., and Brunner, D.: Seasonal
variations of a mixing layer in the lowermost stratosphere as identified by
the CO-O3 correlation from in situ measurements, J. Geophys. Res.-Atmos.,
107, ACL 1-1–ACL 1-11, https://doi.org/10.1029/2000JD000289, 2002. a
Hoor, P., Gurk, C., Brunner, D., Hegglin, M. I., Wernli, H., and Fischer, H.: Seasonality and extent of extratropical TST derived from in-situ CO measurements during SPURT, Atmos. Chem. Phys., 4, 1427–1442, https://doi.org/10.5194/acp-4-1427-2004, 2004. a
Hoor, P., Wernli, H., Hegglin, M. I., and Bönisch, H.: Transport timescales and tracer properties in the extratropical UTLS, Atmos. Chem. Phys., 10, 7929–7944, https://doi.org/10.5194/acp-10-7929-2010, 2010. a
Hoskins, B. J.: Towards a PV‐θ view of the general circulation,
Tellus A, 43, 27–35, https://doi.org/10.1034/j.1600-0870.1991.t01-3-00005.x, 1991. a
Hoskins, B. J., McIntyre, M. E., and Robertson, A. W.: On the use and
significance of isentropic potential vorticity maps, Q. J. R. Meteorol.
Soc., 111, 877–946, https://doi.org/10.1002/qj.49711147002, 1985. a
Jaeger, E. B. and Sprenger, M.: A Northern Hemispheric climatology of indices
for clear air turbulence in the tropopause region derived from ERA40
reanalysis data, J. Geophys. Res.-Atmos., 112, 1–13,
https://doi.org/10.1029/2006JD008189, 2007. a, b
Knox, J. A.: Possible mechanisms of clear-air turbulence in strongly
anticyclonic flows, Mon. Weather Rev., 125, 1251–1259,
https://doi.org/10.1175/1520-0493(1997)125<1251:PMOCAT>2.0.CO;2, 1997. a
Koch, P., Wernli, H., and Davies, H. C.: An event-based jet-stream climatology
and typology, Int. J. Climatol. 26, 283–301, https://doi.org/10.1002/joc.1255,
2006. a
Koteswaram, P.: The Easterly Jet Stream in the Tropics, Tellus, 10, 43–57,
https://doi.org/10.1111/j.2153-3490.1958.tb01984.x, 1958. a
Krisch, I., Ern, M., Hoffmann, L., Preusse, P., Strube, C., Ungermann, J., Woiwode, W., and Riese, M.: Superposition of gravity waves with different propagation characteristics observed by airborne and space-borne infrared sounders, Atmos. Chem. Phys., 20, 11469–11490, https://doi.org/10.5194/acp-20-11469-2020, 2020. a
Krishnamurti, T. N. and Bhalme, H.: Ocillations of a Monsoon System. Part I.
Observational Aspects, J. Atmos. Sci., 33, 1937–1954,
https://doi.org/10.1175/1520-0469(1976)033<1937:OOAMSP>2.0.CO;2, 1976. a
Kunkel, D., Hoor, P., and Wirth, V.: The tropopause inversion layer in baroclinic life-cycle experiments: the role of diabatic processes, Atmos. Chem. Phys., 16, 541–560, https://doi.org/10.5194/acp-16-541-2016, 2016. a
Kunkel, D., Hoor, P., Kaluza, T., Ungermann, J., Kluschat, B., Giez, A., Lachnitt, H.-C., Kaufmann, M., and Riese, M.: Evidence of small-scale quasi-isentropic mixing in ridges of extratropical baroclinic waves, Atmos. Chem. Phys., 19, 12607–12630, https://doi.org/10.5194/acp-19-12607-2019, 2019. a, b, c, d, e, f
Liu, H. L.: Large Wind Shears and Their Implications for Diffusion in Regions
With Enhanced Static Stability: The Mesopause and the Tropopause, J.
Geophys. Res.-Atmos., 122, 9579–9590, https://doi.org/10.1002/2017JD026748, 2017. a, b, c
Madonna, E., Wernli, H., Joos, H., and Martius, O.: Warm conveyor belts in the
ERA-Interim Dataset (1979–2010). Part I: Climatology and potential vorticity
evolution, J. Climate, 27, 3–26, https://doi.org/10.1175/JCLI-D-12-00720.1, 2014. a
Miles, J. W.: On the stability of heterogeneous shear flows, J. Fluid
Mech., 10, 496–508, https://doi.org/10.1017/S0022112061000305, 1961. a
Müller, S. K., Manzini, E., Giorgetta, M., Sato, K., and Nasuno, T.:
Convectively Generated Gravity Waves in High Resolution Models of Tropical
Dynamics, J. Adv. Mod. Earth Sys., 10, 2564–2588,
https://doi.org/10.1029/2018MS001390, 2018. a
Pan, L. L., Randel, W. J., Gary, B. L., Mahoney, M. J., and Hintsa, E. J.:
Definitions and sharpness of the extratropical tropopause: A trace gas
perspective, J. Geophys. Res.-Atmos., 109, 1–11,
https://doi.org/10.1029/2004JD004982, 2004. a, b
Plougonven, R. and Zhang, F.: Internal gravity waves from atmospheric jets and
fronts, Rev. Geophys., 52, 33–76,
https://doi.org/10.1002/2012RG000419, 2014. a
Podglajen, A., Bui, T. P., Dean-Day, J. M., Pfister, L., Jensen, E. J.,
Alexander, M. J., Hertzog, A., Kärcher, B., Plougonven, R., and Randel,
W. J.: Small-scale wind fluctuations in the tropical tropopause layer from
aircraft measurements: Occurrence, nature, and impact on vertical mixing, J.
Atmos. Sci., 74, 3847–3869, https://doi.org/10.1175/JAS-D-17-0010.1, 2017. a
Podglajen, A., Hertzog, A., Plougonven, R., and Legras, B.: Lagrangian gravity wave spectra in the lower stratosphere of current (re)analyses, Atmos. Chem. Phys., 20, 9331–9350, https://doi.org/10.5194/acp-20-9331-2020, 2020. a
Randel, W. J., Wu, F., and Forster, P.: The Extratropical Tropopause Inversion
Layer: Global Observations with GPS Data, and a Radiative Forcing Mechanism,
J. Atmos. Sci., 64, 4489–4496, https://doi.org/10.1175/2007JAS2412.1, 2007. a
Reiter, E. R.: The Nature of Clear Air Turbulence: A Review, in: Proceedings
of a Symposium on Clear Air Turbulence and Its Detection, edited by: Pao, Y. H. and Goldburg, A., Springer, Boston, MA,
https://doi.org/10.1007/978-1-4899-5615-6_2, 1969. a
Riese, M., Ploeger, F., Rap, A., Vogel, B., Konopka, P., Dameris, M., and
Forster, P.: Impact of uncertainties in atmospheric mixing on simulated UTLS
composition and related radiative effects, J. Geophys. Res.-Atmos., 117,
1–10, https://doi.org/10.1029/2012JD017751, 2012. a
Roja Raman, M., Jagannadha Rao, V. V., Venkat Ratnam, M., Rajeevan, M.,
Rao, S. V., Narayana Rao, D., and Prabhakara Rao, N.: Characteristics of
the Tropical Easterly Jet: Long-term trends and their features during active
and break monsoon phases, J. Geophys. Res.-Atmos., 114, 1–14,
https://doi.org/10.1029/2009JD012065, 2009. a, b
Schäfler, A., Harvey, B., Methven, J., Doyle, J. D., Rahm, S., Reitebuch,
O., Weiler, F., and Witschas, B.: Observation of jet stream winds during
nawdex and characterization of systematic meteorological analysis errors,
Mon. Weather Rev., 148, 2889–2907, https://doi.org/10.1175/MWR-D-19-0229.1, 2020. a
Seidel, D. J., Ross, R. J., Angell, J. K., and Reid, G. C.: Climatological
characteristics of the tropical tropopause as revealed by radiosondes, J.
Geophys. Res.-Atmos., 106, 7857–7878, https://doi.org/10.1029/2000JD900837, 2001. a, b
Shapiro, M. A.: The role of turbulent heat flux in the generation of potential
vorticity in the vicinity of upper-level jet stream systems, Mon. Weather Rev.,
104, 892–906,
https://doi.org/10.1175/1520-0493(1976)104<0892:TROTHF>2.0.CO;2, 1976. a, b
Shapiro, M. A.: Further evidence of the mesoscale and turbulent structure of
upper level jet stream–frontal zone systems, Mon. Weather Rev., 106, 1100–1111, https://doi.org/10.1175/1520-0493(1978)106<1100:FEOTMA>2.0.CO;2, 1978. a, b
Sharman, R. D., Trier, S. B., Lane, T. P., and Doyle, J. D.: Sources and
dynamics of turbulence in the upper troposphere and lower stratosphere: A
review, Geophys. Res. Lett., 39, 1–9, https://doi.org/10.1029/2012GL051996, 2012. a
Shaw, T. A., Baldwin, M., Barnes, E. A., Caballero, R., Garfinkel, C. I.,
Hwang, Y. T., Li, C., O'Gorman, P. A., Rivière, G., Simpson, I. R., and
Voigt, A.: Storm track processes and the opposing influences of climate
change, Nat. Geosci., 9, 656–664, https://doi.org/10.1038/ngeo2783, 2016. a
Škerlak, B., Sprenger, M., Pfahl, S., Tyrlis, E., and Wernli, H.:
Tropopause folds in ERA-interim: Global climatology and relation to extreme
weather events, J. Geophys. Res.-Atmos., 120, 4860–4877,
https://doi.org/10.1002/2014JD022787, 2015. a
Spreitzer, E., Attinger, R., Boettcher, M., Forbes, R., Wernli, H., and Joos,
H.: Modification of potential vorticity near the tropopause by
nonconservative processes in the ECMWF model, J. Atmos. Sci., 76,
1709–1726, https://doi.org/10.1175/JAS-D-18-0295.1, 2019. a, b, c
Stohl, A., Bonasoni, P., Cristofanelli, P., Collins, W., Feichter, J., Frank,
A., Forster, C., Gerasopoulos, E., Gäggeler, H., James, P., Kentarchos,
T., Kromp-Kolb, H., Krüger, B., Land, C., Meloen, J., Papayannis, A.,
Priller, A., Seibert, P., Sprenger, M., Roelofs, G. J., Scheel, H. E.,
Schnabel, C., Siegmund, P., Tobler, L., Trickl, T., Wernli, H., Wirth, V.,
Zanis, P., and Zerefos, C.: Stratosphere-troposphere exchange: A review, and
what we have learned from STACCATO, J. Geophys. Res.-Atmos., 108, 1–15,
https://doi.org/10.1029/2002jd002490, 2003. a
Sullivan, S. C., Schiro, K. A., Stubenrauch, C., and Gentine, P.: The Response
of Tropical Organized Convection to El Niño Warming, J. Geophys.
Res.-Atmos., 124, 8481–8500, https://doi.org/10.1029/2019JD031026, 2019. a
Sunilkumar, S. V., Babu, A., and Parameswaran, K.: Mean structure of the
tropical tropopause and its variability over the Indian longitude sector,
Clim. Dyn., 40, 1125–1140, https://doi.org/10.1007/s00382-012-1496-8, 2013. a
Sunilkumar, S. V., Muhsin, M., Parameswaran, K., Venkat Ratnam, M., Ramkumar,
G., Rajeev, K., Krishna Murthy, B. V., Sambhu Namboodiri, K. V.,
Subrahmanyam, K. V., Kishore Kumar, K., and Shankar Das, S.:
Characteristics of turbulence in the troposphere and lower stratosphere over
the Indian Peninsula, J. Atmos. Sol.-Terr. Phys., 133, 36–53,
https://doi.org/10.1016/j.jastp.2015.07.015, 2015. a, b, c, d, e
Suzuki, S., Nakamura, T., Ejiri, M. K., Tsutsumi, M., Shiokawa, K., and
Kawahara, T. D.: Simultaneous airglow, lidar, and radar measurements of
mesospheric gravity waves over Japan, J. Geophys. Res.-Atmos., 115, 1–12,
https://doi.org/10.1029/2010JD014674, 2010. a
Trier, S. B., Sharman, R. D., Muñoz-Esparza, D., and Lane, T. P.:
Environment and Mechanisms of Severe Turbulence in a Midlatitude Cyclone,
J. Atmos. Sci., 77, 3869–3889, https://doi.org/10.1175/jas-d-20-0095.1, 2020. a
Whiteway, J. A., Klaassen, G. P., Bradshaw, N. G., and Hacker, J.: Transition
to turbulence in shear above the tropopause, Geophys. Res. Lett., 31, 2–5,
https://doi.org/10.1029/2003GL018509, 2004. a
Wirth, V.: Static Stability in the Extratropical Tropopause Region, J. Atmos.
Sci., 60, 1395–1409, https://doi.org/10.1175/1520-0469(2003)060<1395:SSITET>2.0.CO;2,
2003.
a
Wirth, V.: A dynamical mechanism for tropopause sharpening, Meteorol.
Z., 13, 477–484, https://doi.org/10.1127/0941-2948/2004/0013-0477, 2004. a
WMO: Meteorology – A threedimensional science: Second session of the
Commission for Aerology, WMO Bulletin, VI, 134–138, 1957. a
Yang, S., Lau, K. M., and Kim, K. M.: Variations of the East Asian jet stream
and Asian-Pacific-American winter climate anomalies, J. Climate, 15,
306–325, https://doi.org/10.1175/1520-0442(2002)015<0306:voteaj>2.0.co;2, 2002. a, b
Zhang, Y., Zhang, S., Huang, C., Huang, K., Gong, Y., and Gan, Q.: The
interaction between the tropopause inversion layer and the inertial gravity
wave activities revealed by radiosonde observations at a midlatitude station
Yehui, J. Geophys. Res.-Atmos., 120, 8099–8111,
https://doi.org/10.1002/2015JD023115, 2015. a, b, c, d
Zierl, B. and Wirth, V.: The influence of radiation on tro- popause behavior
and stratosphere-troposphere exchange in an upper tropospheric anticyclone.,
J. Geophys. Res.-Atmos., 102, 23883–23894,
https://doi.org/10.1029/97JD01667, 1997. a
Short summary
We present a 10-year analysis on the occurrence of strong wind shear in the Northern Hemisphere, focusing on the region around the transport barrier that separates the first two layers of the atmosphere. The major result of our analysis is that strong wind shear above a certain threshold occurs frequently and nearly exclusively in this region, which, as an indicator for turbulent mixing, might have major implications concerning the separation efficiency of the transport barrier.
We present a 10-year analysis on the occurrence of strong wind shear in the Northern Hemisphere,...
