Articles | Volume 5, issue 2
https://doi.org/10.5194/wcd-5-779-2024
© Author(s) 2024. 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-5-779-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
31 May 2024
Research article |
| 31 May 2024
| 31 May 2024
Divergent convective outflow in ICON deep-convection-permitting and parameterised deep convection simulations
Edward Groot
CORRESPONDING AUTHOR
Institut für Physik der Atmosphäre, Johannes Gutenberg-Universität, Johann-Joachim-Becher-Weg 21, Mainz, Germany
Atmospheric, Oceanic and Planetary Physics, University of Oxford, Sherrington Road, Oxford, UK
Patrick Kuntze
Institut für Physik der Atmosphäre, Johannes Gutenberg-Universität, Johann-Joachim-Becher-Weg 21, Mainz, Germany
Annette Miltenberger
Institut für Physik der Atmosphäre, Johannes Gutenberg-Universität, Johann-Joachim-Becher-Weg 21, Mainz, Germany
Holger Tost
Institut für Physik der Atmosphäre, Johannes Gutenberg-Universität, Johann-Joachim-Becher-Weg 21, Mainz, Germany
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Edward Groot and Holger Tost
Atmos. Chem. Phys., 23, 6065–6081, https://doi.org/10.5194/acp-23-6065-2023, https://doi.org/10.5194/acp-23-6065-2023, 2023
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It is shown that the outflow from cumulonimbus clouds or thunderstorms in the upper troposphere and lower stratosphere in idealized high-resolution simulations (LESs) depends linearly on the net amount of latent heat released by the cloud for fixed geometry of the clouds. However, it is shown that, in more realistic situations, convective organization and aggregation (collecting mechanisms of cumulonimbus clouds) affect the amount of outflow non-linearly through non-idealized geometry.
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Thunderstorm systems play an important role in the dynamics of the Earth’s atmosphere, and some of them form a well-organised line: squall lines. Simulations of such squall lines with very small initial perturbations are compared to a reference simulation. The evolution of perturbations and processes amplifying them are analysed. It is shown that the formation of new secondary thunderstorm cells (after the initial primary cells) directly ahead of the line affects the spread strongly.
Edward Groot and Holger Tost
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1142, https://doi.org/10.5194/acp-2020-1142, 2020
Publication in ACP not foreseen
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Sensitivities and variability of upper tropospheric flow (~10 km height) resulting immediately and as a direct consequence of (thunder)storm activity have been modeled in detail down to resolutions of 100–200 m and explored for different (organisation/) storm types. It is shown that the amount of water condensation explains much of emerging variability in upper atmospheric flow. Part of the effects on the nearby upper atmospheric flow is suggested to be explained by (organisation/) storm type.
Tim Lüttmer, Annette Miltenberger, and Peter Spichtinger
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We investigate ice formation pathways in a warm conveyor belt case study. We employ a multi-phase microphysics scheme that distinguishes between ice from different nucleation processes. Ice crystals in the cirrus outflow mostly stem from in situ formation. Hence, they were formed directly from the vapor phase. Sedimentational redistribution modulates cirrus properties and leads to disagreement between cirrus origin classifications based on thermodynamic history and nucleation processes.
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For the balloon-borne detection of particles (diameter 0.4 < Dp < 40 µm), the Universal Cloud and Aerosol Sounding System (UCASS) was used, whose sample flow is determined by GPS-measured ascent rates. In flights, actual UCASS sample flows rarely match the ascent rates. Errors are minimised by real-time detection of the UCASS flows, e.g. by implementing a thermal flow sensor (TFS) within the UCASS. The TFSs were tested in flight and calibrated at up to 10 m s−1 and at variable angles of attack.
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Anna Breuninger, Philipp Joppe, Jonas Wilsch, Cornelis Schwenk, Heiko Bozem, Nicolas Emig, Laurin Merkel, Rainer Rossberg, Timo Keber, Arthur Kutschka, Philipp Waleska, Stefan Hofmann, Sarah Richter, Florian Ungeheuer, Konstantin Dörholt, Thorsten Hoffmann, Annette Miltenberger, Johannes Schneider, Peter Hoor, and Alexander L. Vogel
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Matthias Kohl, Christoph Brühl, Jennifer Schallock, Holger Tost, Patrick Jöckel, Adrian Jost, Steffen Beirle, Michael Höpfner, and Andrea Pozzer
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SO2 from explosive volcanic eruptions reaching the stratosphere can oxidize and form sulfur aerosols, potentially persisting for several years. We developed a new submodel, Explosive Volcanic ERuptions (EVER), that seamlessly includes stratospheric volcanic SO2 emissions in global numerical simulations based on a novel standard historical model setup, successfully evaluated with satellite observations. Sensitivity studies on the Nabro eruption in 2011 evaluate different emission methods.
Patrick Konjari, Christian Rolf, Martina Krämer, Armin Afchine, Nicole Spelten, Irene Bartolome Garcia, Annette Miltenberger, Nicolar Emig, Philipp Joppe, Johannes Schneider, Yun Li, Andreas Petzold, Heiko Bozem, and Peter Hoor
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Cornelis Schwenk, Annette Miltenberger, and Annika Oertel
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Adrienne Jeske and Holger Tost
EGUsphere, https://doi.org/10.5194/egusphere-2025-293, https://doi.org/10.5194/egusphere-2025-293, 2025
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Sarah Brüning and Holger Tost
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Sarah Brüning and Holger Tost
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Nicolas Emig, Annette K. Miltenberger, Peter M. Hoor, and Andreas Petzold
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Ryan Vella, Matthew Forrest, Andrea Pozzer, Alexandra P. Tsimpidi, Thomas Hickler, Jos Lelieveld, and Holger Tost
Atmos. Chem. Phys., 25, 243–262, https://doi.org/10.5194/acp-25-243-2025, https://doi.org/10.5194/acp-25-243-2025, 2025
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Chun Hang Chau, Peter Hoor, and Holger Tost
EGUsphere, https://doi.org/10.5194/egusphere-2024-3805, https://doi.org/10.5194/egusphere-2024-3805, 2024
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This study examines how the turbulence in the upper troposphere/lower stratosphere could modify the tracer distribution under different situations. Using a multi-scale chemistry model, we find that both the pre-existing tracer gradient and the dynamical and thermodynamically forcing play a role in modifying the tracer distribution. These results allow further research on the UTLS turbulent mixing and its implications for the climate system.
Cornelis Schwenk and Annette Miltenberger
Atmos. Chem. Phys., 24, 14073–14099, https://doi.org/10.5194/acp-24-14073-2024, https://doi.org/10.5194/acp-24-14073-2024, 2024
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Warm conveyor belts (WCBs) transport moisture into the upper atmosphere, where it acts as a greenhouse gas. This transport is not well understood, and the role of rapidly rising air is unclear. We simulate a WCB and look at fast- and slow-rising air to see how moisture is (differently) transported. We find that for fast-ascending air more ice particles reach higher into the atmosphere and that frozen cloud particles are removed differently than during slow ascent, which has more water vapour.
Anna Martin, Veronika Gayler, Benedikt Steil, Klaus Klingmüller, Patrick Jöckel, Holger Tost, Jos Lelieveld, and Andrea Pozzer
Geosci. Model Dev., 17, 5705–5732, https://doi.org/10.5194/gmd-17-5705-2024, https://doi.org/10.5194/gmd-17-5705-2024, 2024
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The study evaluates the land surface and vegetation model JSBACHv4 as a replacement for the simplified submodel SURFACE in EMAC. JSBACH mitigates earlier problems of soil dryness, which are critical for vegetation modelling. When analysed using different datasets, the coupled model shows strong correlations of key variables, such as land surface temperature, surface albedo and radiation flux. The versatility of the model increases significantly, while the overall performance does not degrade.
Simon Rosanka, Holger Tost, Rolf Sander, Patrick Jöckel, Astrid Kerkweg, and Domenico Taraborrelli
Geosci. Model Dev., 17, 2597–2615, https://doi.org/10.5194/gmd-17-2597-2024, https://doi.org/10.5194/gmd-17-2597-2024, 2024
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The capabilities of the Modular Earth Submodel System (MESSy) are extended to account for non-equilibrium aqueous-phase chemistry in the representation of deliquescent aerosols. When applying the new development in a global simulation, we find that MESSy's bias in modelling routinely observed reduced inorganic aerosol mass concentrations, especially in the United States. Furthermore, the representation of fine-aerosol pH is particularly improved in the marine boundary layer.
Sarah Brüning, Stefan Niebler, and Holger Tost
Atmos. Meas. Tech., 17, 961–978, https://doi.org/10.5194/amt-17-961-2024, https://doi.org/10.5194/amt-17-961-2024, 2024
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We apply the Res-UNet to derive a comprehensive 3D cloud tomography from 2D satellite data over heterogeneous landscapes. We combine observational data from passive and active remote sensing sensors by an automated matching algorithm. These data are fed into a neural network to predict cloud reflectivities on the whole satellite domain between 2.4 and 24 km height. With an average RMSE of 2.99 dBZ, we contribute to closing data gaps in the representation of clouds in observational data.
Ryan Vella, Andrea Pozzer, Matthew Forrest, Jos Lelieveld, Thomas Hickler, and Holger Tost
Biogeosciences, 20, 4391–4412, https://doi.org/10.5194/bg-20-4391-2023, https://doi.org/10.5194/bg-20-4391-2023, 2023
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We investigated the effect of the El Niño–Southern Oscillation (ENSO) on biogenic volatile organic compound (BVOC) emissions from plants. ENSO events can cause a significant increase in these emissions, which have a long-term impact on the Earth's atmosphere. Persistent ENSO conditions can cause long-term changes in vegetation, resulting in even higher BVOC emissions. We link ENSO-induced emission anomalies with driving atmospheric and vegetational variables.
Annika Oertel, Annette K. Miltenberger, Christian M. Grams, and Corinna Hoose
Atmos. Chem. Phys., 23, 8553–8581, https://doi.org/10.5194/acp-23-8553-2023, https://doi.org/10.5194/acp-23-8553-2023, 2023
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Warm conveyor belts (WCBs) are cloud- and precipitation-producing airstreams in extratropical cyclones that are important for the large-scale flow and cloud radiative forcing. We analyze cloud formation processes during WCB ascent in a two-moment microphysics scheme. Quantification of individual diabatic heating rates shows the importance of condensation, vapor deposition, rain evaporation, melting, and cloud-top radiative cooling for total heating and WCB-related potential vorticity structure.
Edward Groot and Holger Tost
Atmos. Chem. Phys., 23, 6065–6081, https://doi.org/10.5194/acp-23-6065-2023, https://doi.org/10.5194/acp-23-6065-2023, 2023
Short summary
Short summary
It is shown that the outflow from cumulonimbus clouds or thunderstorms in the upper troposphere and lower stratosphere in idealized high-resolution simulations (LESs) depends linearly on the net amount of latent heat released by the cloud for fixed geometry of the clouds. However, it is shown that, in more realistic situations, convective organization and aggregation (collecting mechanisms of cumulonimbus clouds) affect the amount of outflow non-linearly through non-idealized geometry.
Ryan Vella, Matthew Forrest, Jos Lelieveld, and Holger Tost
Geosci. Model Dev., 16, 885–906, https://doi.org/10.5194/gmd-16-885-2023, https://doi.org/10.5194/gmd-16-885-2023, 2023
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Biogenic volatile organic compounds (BVOCs) are released by vegetation and have a major impact on atmospheric chemistry and aerosol formation. Non-interacting vegetation constrains the majority of numerical models used to estimate global BVOC emissions, and thus, the effects of changing vegetation on emissions are not addressed. In this work, we replace the offline vegetation with dynamic vegetation states by linking a chemistry–climate model with a global dynamic vegetation model.
Edward Groot and Holger Tost
Atmos. Chem. Phys., 23, 565–585, https://doi.org/10.5194/acp-23-565-2023, https://doi.org/10.5194/acp-23-565-2023, 2023
Short summary
Short summary
Thunderstorm systems play an important role in the dynamics of the Earth’s atmosphere, and some of them form a well-organised line: squall lines. Simulations of such squall lines with very small initial perturbations are compared to a reference simulation. The evolution of perturbations and processes amplifying them are analysed. It is shown that the formation of new secondary thunderstorm cells (after the initial primary cells) directly ahead of the line affects the spread strongly.
Mohamed Abdelkader, Georgiy Stenchikov, Andrea Pozzer, Holger Tost, and Jos Lelieveld
Atmos. Chem. Phys., 23, 471–500, https://doi.org/10.5194/acp-23-471-2023, https://doi.org/10.5194/acp-23-471-2023, 2023
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We study the effect of injected volcanic ash, water vapor, and SO2 on the development of the volcanic cloud and the stratospheric aerosol optical depth (AOD). Both are sensitive to the initial injection height and to the aging of the volcanic ash shaped by heterogeneous chemistry coupled with the ozone cycle. The paper explains the large differences in AOD for different injection scenarios, which could improve the estimate of the radiative forcing of volcanic eruptions.
Andrea Pozzer, Simon F. Reifenberg, Vinod Kumar, Bruno Franco, Matthias Kohl, Domenico Taraborrelli, Sergey Gromov, Sebastian Ehrhart, Patrick Jöckel, Rolf Sander, Veronica Fall, Simon Rosanka, Vlassis Karydis, Dimitris Akritidis, Tamara Emmerichs, Monica Crippa, Diego Guizzardi, Johannes W. Kaiser, Lieven Clarisse, Astrid Kiendler-Scharr, Holger Tost, and Alexandra Tsimpidi
Geosci. Model Dev., 15, 2673–2710, https://doi.org/10.5194/gmd-15-2673-2022, https://doi.org/10.5194/gmd-15-2673-2022, 2022
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A newly developed setup of the chemistry general circulation model EMAC (ECHAM5/MESSy for Atmospheric Chemistry) is evaluated here. A comprehensive organic degradation mechanism is used and coupled with a volatility base model.
The results show that the model reproduces most of the tracers and aerosols satisfactorily but shows discrepancies for oxygenated organic gases. It is also shown that this model configuration can be used for further research in atmospheric chemistry.
Stefan Niebler, Annette Miltenberger, Bertil Schmidt, and Peter Spichtinger
Weather Clim. Dynam., 3, 113–137, https://doi.org/10.5194/wcd-3-113-2022, https://doi.org/10.5194/wcd-3-113-2022, 2022
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We use machine learning to create a network that detects and classifies four types of synoptic-scale weather fronts from ERA5 atmospheric reanalysis data. We present an application of our method, showing its use case in a scientific context. Additionally, our results show that multiple sources of training data are necessary to perform well on different regions, implying differences within those regions. Qualitative evaluation shows that the results are physically plausible.
Rachel E. Hawker, Annette K. Miltenberger, Jill S. Johnson, Jonathan M. Wilkinson, Adrian A. Hill, Ben J. Shipway, Paul R. Field, Benjamin J. Murray, and Ken S. Carslaw
Atmos. Chem. Phys., 21, 17315–17343, https://doi.org/10.5194/acp-21-17315-2021, https://doi.org/10.5194/acp-21-17315-2021, 2021
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We find that ice-nucleating particles (INPs), aerosols that can initiate the freezing of cloud droplets, cause substantial changes to the properties of radiatively important convectively generated anvil cirrus. The number concentration of INPs had a large effect on ice crystal number concentration while the INP temperature dependence controlled ice crystal size and cloud fraction. The results indicate information on INP number and source is necessary for the representation of cloud glaciation.
Ralf Weigel, Christoph Mahnke, Manuel Baumgartner, Martina Krämer, Peter Spichtinger, Nicole Spelten, Armin Afchine, Christian Rolf, Silvia Viciani, Francesco D'Amato, Holger Tost, and Stephan Borrmann
Atmos. Chem. Phys., 21, 13455–13481, https://doi.org/10.5194/acp-21-13455-2021, https://doi.org/10.5194/acp-21-13455-2021, 2021
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In July and August 2017, the StratoClim mission took place in Nepal with eight flights of the M-55 Geophysica at up to 20 km in the Asian monsoon anticyclone. New particle formation (NPF) next to cloud ice was detected in situ by abundant nucleation-mode aerosols (> 6 nm) along with ice particles (> 3 µm). NPF was observed mainly below the tropopause, down to 15 % being non-volatile residues. Observed intra-cloud NPF indicates its importance for the composition in the tropical tropopause layer.
Vinod Kumar, Julia Remmers, Steffen Beirle, Joachim Fallmann, Astrid Kerkweg, Jos Lelieveld, Mariano Mertens, Andrea Pozzer, Benedikt Steil, Marc Barra, Holger Tost, and Thomas Wagner
Atmos. Meas. Tech., 14, 5241–5269, https://doi.org/10.5194/amt-14-5241-2021, https://doi.org/10.5194/amt-14-5241-2021, 2021
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We present high-resolution regional atmospheric chemistry model simulations focused around Germany. We highlight the importance of spatial resolution of the model itself as well as the input emissions inventory and short-scale temporal variability of emissions for simulations. We propose a consistent approach for evaluating the simulated vertical distribution of NO2 using MAX-DOAS measurements while also considering its spatial sensitivity volume and change in sensitivity within this volume.
Rachel E. Hawker, Annette K. Miltenberger, Jonathan M. Wilkinson, Adrian A. Hill, Ben J. Shipway, Zhiqiang Cui, Richard J. Cotton, Ken S. Carslaw, Paul R. Field, and Benjamin J. Murray
Atmos. Chem. Phys., 21, 5439–5461, https://doi.org/10.5194/acp-21-5439-2021, https://doi.org/10.5194/acp-21-5439-2021, 2021
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The impact of aerosols on clouds is a large source of uncertainty for future climate projections. Our results show that the radiative properties of a complex convective cloud field in the Saharan outflow region are sensitive to the temperature dependence of ice-nucleating particle concentrations. This means that differences in the aerosol source or composition, for the same aerosol size distribution, can cause differences in the outgoing radiation from regions dominated by tropical convection.
Annette K. Miltenberger and Paul R. Field
Atmos. Chem. Phys., 21, 3627–3642, https://doi.org/10.5194/acp-21-3627-2021, https://doi.org/10.5194/acp-21-3627-2021, 2021
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The formation of ice in clouds is an important processes in mixed-phase and ice-phase clouds. However, the representation of ice formation in numerical models is highly uncertain. In the last decade, several new parameterizations for heterogeneous freezing have been proposed. Here, we investigate the impact of the parameterization choice on the representation of the convective cloud field and compare the impact to that of initial condition uncertainty.
Sara Bacer, Sylvia C. Sullivan, Odran Sourdeval, Holger Tost, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 21, 1485–1505, https://doi.org/10.5194/acp-21-1485-2021, https://doi.org/10.5194/acp-21-1485-2021, 2021
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We investigate the relative importance of the rates of both microphysical processes and unphysical correction terms that act as sources or sinks of ice crystals in cold clouds. By means of numerical simulations performed with a global chemistry–climate model, we assess the relevance of these rates at global and regional scales. This estimation is of fundamental importance to assign priority to the development of microphysics parameterizations and compare model output with observations.
Edward Groot and Holger Tost
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1142, https://doi.org/10.5194/acp-2020-1142, 2020
Publication in ACP not foreseen
Short summary
Short summary
Sensitivities and variability of upper tropospheric flow (~10 km height) resulting immediately and as a direct consequence of (thunder)storm activity have been modeled in detail down to resolutions of 100–200 m and explored for different (organisation/) storm types. It is shown that the amount of water condensation explains much of emerging variability in upper atmospheric flow. Part of the effects on the nearby upper atmospheric flow is suggested to be explained by (organisation/) storm type.
Cited articles
Adams-Selin, R. D.: Sensitivity of MCS Low-Frequency Gravity Waves to Microphysical Variations, J. Atmos. Sci., 77, 3461–3477, https://doi.org/10.1175/JAS-D-19-0347.1, 2020b. a, b, c, d
Arakawa, A.: The Cumulus Parameterization Problem: Past, Present, and Future, J. Climate, 17, 2493–2525, 2004. a
Baumgart, M., Ghinassi, P., Wirth, V., Selz, T., Craig, G. C., and Riemer, M.: Quantitative View on the Processes Governing the Upscale Error Growth up to the Planetary Scale Using a Stochastic Convection Scheme, Mon. Weather Rev., 147, 1713–1731, https://doi.org/10.1175/mwr-d-18-0292.1, 2019. a, b, c, d
Becker, T., Bechtold, P., and Sandu, I.: Characteristics of convective precipitation over tropical Africa in storm-resolving global simulations, Q. J. Roy. Meteor. Soc., 147, 4388–4407, https://doi.org/10.1002/qj.4185, 2021. a, b, c
Bierdel, L., Selz, T., and Craig, G.: Theoretical aspects of upscale error growth through the mesoscales: an analytical model, Q. J. Roy. Meteor. Soc., 143, 3048–3059, https://doi.org/10.1002/qj.3160, 2017. a, b
Bierdel, L., Selz, T., and Craig, G. C.: Theoretical aspects of upscale error growth on the mesoscales: Idealized numerical simulations, Q. J. Roy. Meteor. Soc., 144, 682–694, https://doi.org/10.1002/qj.3236, 2018. a, b
Bretherton, C. S. and Smolarkiewicz, P. K.: Gravity Waves, Compensating Subsidence and Detrainment around Cumulus Clouds, J. Atmos. Sci., 46, 740–759, https://doi.org/10.1175/1520-0469(1989)046<0740:GWCSAD>2.0.CO;2, 1989. a, b
Brown, A.: Large-eddy simulation and parametrization of the effects of shear on shallow cumulus convection, Bound.-Lay. Meteorol., 91, 65–80, 1999. a
Coniglio, M. C., Stensrud, D. J., and Wicker, L. J.: Effects of upper-level shear on the structure and maintenance of strong quasi-linear mesoscale convective systems, J. Atmos. Sci., 63, 1231–1252, https://doi.org/10.1175/jas3681.1, 2006. a, b
Done, J. M., Craig, G. C., Gray, S. L., Clark, P. A., and Gray, M. E. B.: Mesoscale simulations of organized convection: Importance of convective equilibrium, Q. J. Roy. Meteor. Soc., 132, 737–756, https://doi.org/10.1256/qj.04.84, 2006. a, b, c
Durran, D. and Gingrich, M.: Atmospheric Predictability: Why Butterflies Are Not of Practical Importance, J. Atmos. Sci., 71, 2476–2488, https://doi.org/10.1175/JAS-D-14-0007.1, 2014. a
Grant, L. D., Lane, T. P., and van den Heever, S. C.: The role of cold pools in tropical oceanic convective systems, J. Atmos. Sci., 75, 2615–2634, https://doi.org/10.1175/jas-d-17-0352.1, 2018. a, b, c
Grant, L. D., Moncrieff, M. W., Lane, T. P., and van den Heever, S. C.: Shear-parallel tropical convective systems: Importance of cold pools and wind shear, Geophys. Res. Lett., 47, e2020GL087720, https://doi.org/10.1029/2020GL087720, 2020. a
Groot, E.: An analysis of variability and predictability of organised deep convection and its divergent upper tropospheric outflow, Dissertation, Johannes Gutenberg-Universität Mainz, Mainz, 134 pp., https://doi.org/10.25358/openscience-9115, 2023. a
Groot, E. and Kuntze, P.: Dataset of “Divergent convective outflow in ICON deep convection permitting and parameterised deep convection simulations”: sample simulations and the tool “EFiDaGe for CoSy”, Zenodo [code/data set], https://doi.org/10.5281/zenodo.7541630, 2023. a, b, c, d
Groot, E. and Tost, H.: Evolution of squall line variability and error growth in an ensemble of large eddy simulations, Atmos. Chem. Phys., 23, 565–585, https://doi.org/10.5194/acp-23-565-2023, 2023a. a, b, c
Houze Jr., R. A.: Mesoscale convective systems, Rev. Geophys., 42, RG4003, https://doi.org/10.1029/2004RG000150, 2004. a, b, c
Houze Jr., R. A.: 100 Years of Research on Mesoscale Convective Systems, Meteor. Mon., 59, 17.1–17.54, https://doi.org/10.1175/AMSMONOGRAPHS-D-18-0001.1, 2018. a
Judt, F.: Atmospheric Predictability of the Tropics, Middle Latitudes, and Polar Regions Explored through Global Storm-Resolving Simulations, J. Atmos. Sci., 77, 257–276, https://doi.org/10.1175/JAS-D-19-0116.1, 2020. a
Keane, R. J., Craig, G., Keil, C., and Zängl, G.: The Plant–Craig Stochastic Convection Scheme in ICON and Its Scale Adaptivity, J. Atmos. Sci., 71, 3404–3415, https://doi.org/10.1175/JAS-D-13-0331.1, 2014. a, b
Lane, T. P. and Reeder, M. J.: Convectively Generated Gravity Waves and Their Effect on the Cloud Environment, J. Atmos. Sci., 58, 2427–2440, https://doi.org/10.1175/1520-0469(2001)058<2427:CGGWAT>2.0.CO;2, 2001. a
Lawrence, M. G. and Salzmann, M.: On interpreting studies of tracer transport by deep cumulus convection and its effects on atmospheric chemistry, Atmos. Chem. Phys., 8, 6037–6050, https://doi.org/10.5194/acp-8-6037-2008, 2008. a, b
Lorenz, E.: The predictability of a flow which possesses many scales of motion, Tellus, 21, 289–307, https://doi.org/10.3402/tellusa.v21i3.10086, 1969. a
Mapes, B. E.: Gregarious Tropical Convection, J. Atmos. Sci., 50, 2026–2037, https://doi.org/10.1175/1520-0469(1993)050<2026:GTC>2.0.CO;2, 1993. a, b
Matsunobu, T., Keil, C., and Barthlott, C.: The impact of microphysical uncertainty conditional on initial and boundary condition uncertainty under varying synoptic control, Weather Clim. Dynam., 3, 1273–1289, https://doi.org/10.5194/wcd-3-1273-2022, 2022. a
Moncrieff, M. W.: Organized Convective Systems: Archetypal Dynamical Models, Mass and Momentum Flux Theory, and Parametrization, Q. J. Roy. Meteor. Soc., 118, 819–850, https://doi.org/10.1002/qj.49711850703, 1992. a
Morrison, H.: Impacts of Updraft Size and Dimensionality on the Perturbation Pressure and Vertical Velocity in Cumulus Convection. Part I: Simple, Generalized Analytic Solutions, J. Atmos. Sci., 73, 1441–1454, https://doi.org/10.1175/JAS-D-15-0040.1, 2016a. a
Morrison, H.: Impacts of Updraft Size and Dimensionality on the Perturbation Pressure and Vertical Velocity in Cumulus Convection. Part II: Comparison of Theoretical and Numerical Solutions and Fully Dynamical Simulations, J. Atmos. Sci., 73, 1455–1480, https://doi.org/10.1175/JAS-D-15-0041.1, 2016b. a
Muller, C., Yang, D., Craig, G., Cronin, T., Fildier, B., Haerter, J., Hohenegger, C., Mapes, B., Randall, D., Shamekh, S., and Sherwood, S.: Spontaneous Aggregation of Convective Storms, Annu. Rev. Fluid Mech., 54, 133–157, https://doi.org/10.1146/annurev-fluid-022421-011319, 2022. a
Ollinaho, P., Lock, S., Leutbecher, M., Bechtold, P., Beljaars, A., Bozzo, A., Forbes, R., Haiden, T., Hogan, R., and Sandu, I.: Towards process-level representation of model uncertainties: stochastically perturbed parametrizations in the ECMWF ensemble, Q. J. Roy. Meteor. Soc., 143, 408–422, 2017. a
OpenCV: Open Source Computer Vision Library, https://opencv.org (last access: 17 May 2024), 2022. a
OpenCV: Open Source Computer Vision Library, GitHub [code], https://github.com/opencv/opencv, last access: 17 May 2024. a
Palmer, T.: Stochastic weather and climate models, Nat. Rev. Phys., 1, 463–471, 2019. a
Pandya, R., Durran, D., and Bretherton, C.: Comments on “Thermally Forced Gravity Waves in an Atmosphere at Rest”, J. Atmos. Sci., 50, 4097–4101, https://doi.org/10.1175/1520-0469(1993)050<4097:COFGWI>2.0.CO;2, 1993. a
Rodwell, M. J., Magnusson, L., Bauer, P., Bechtold, P., Bonavita, M., Cardinali, C., Diamantakis, M., Earnshaw, P., Garcia-Mendez, A., Isaksen, L., Källén, E., Klocke, D., Lopez, P., McNally, T., Persson, A., Prates, F., and Wedi, N.: Characteristics of Occasional Poor Medium-Range Weather Forecasts for Europe, B. Am. Meteorol. Soc., 94, 1393–1405, https://doi.org/10.1175/bams-d-12-00099.1, 2013. a, b, c, d
Rotunno, R., Klemp, J. B., and Weisman, M. L.: A theory for strong, long-lived squall lines, J. Atmos. Sci., 45, 463–485, https://doi.org/10.1175/1520-0469(1988)045<0463:ATFSLL>2.0.CO;2, 1988. a
Schumacher, C., Houze, R. A., and Kraucunas, I.: The Tropical Dynamical Response to Latent Heating Estimates Derived from the TRMM Precipitation Radar, J. Atmos. Sci., 61, 1341–1358, https://doi.org/10.1175/1520-0469(2004)061<1341:TTDRTL>2.0.CO;2, 2004. a
Seifert, A.: A revised cloud microphysical parameterization for COSMO-LME, COSMO Newsletter, 7, 25–28, 2008. a
Seifert, A. and Beheng, K.: A two-moment cloud microphysics parameterization for mixed-phase clouds. Part 1: Model description, Meteorol. Atmos. Phys., 92, 45–66, 2006. a
Selz, T. and Craig, G. C.: Upscale Error Growth in a High-Resolution Simulation of a Summertime Weather Event over Europe, Mon. Weather Rev., 143, 813–827, https://doi.org/10.1175/mwr-d-14-00140.1, 2015a. a
Selz, T. and Craig, G. C.: Simulation of upscale error growth with a stochastic convection scheme, Geophys. Rese. Lett., 42, 3056–3062, https://doi.org/10.1002/2015gl063525, 2015b. a
Selz, T., Riemer, M., and Craig, G.: The transition from practical to intrinsic predictability of midlatitude weather, J. Atmos. Sci., 79, 2013–2030, https://doi.org/10.1175/JAS-D-21-0271.1, 2022. a, b
Shutts, G. J. and Gray, M. E. B.: A numerical modelling study of the geostrophic adjustment process following deep convection, Q. J. Roy. Meteor. Soc., 120, 1145–1178, https://doi.org/10.1002/qj.49712051903, 1994. a
Skamarock, W. C.: Evaluating mesoscale NWP models using kinetic energy spectra, Mon. Weather Rev., 132, 3019–3032, https://doi.org/10.1175/mwr2830.1, 2004. a
Stechmann, S. N. and Majda, A. J.: Gravity waves in shear and implications for organized convection, 66, 2579–2599, https://doi.org/10.1175/2009JAS2976.1, 2009. a
Tiedtke, M.: A comprehensive mass flux scheme for cumulus parameterization in large-scale models, Mon. Weather Rev., 117, 1779–1800, 1989. a
Trier, S. B., Skamarock, W. C., and LeMone, M. A.: Structure and Evolution of the 22 February 1993 TOGA COARE Squall Line: Organization Mechanisms Inferred from Numerical Simulation, J. Atmos. Sci., 54, 386–407, https://doi.org/10.1175/1520-0469(1997)054<0386:SAEOTF>2.0.CO;2, 1997. a, b, c
Weyn, J. A. and Durran, D. R.: The Dependence of the Predictability of Mesoscale Convective Systems on the Horizontal Scale and Amplitude of Initial Errors in Idealized Simulations, J. Atmos. Sci., 74, 2191–2210, https://doi.org/10.1175/JAS-D-17-0006.1, 2017. a
Wilhelm, J., Mohr, S., Punge, H. J., Mühr, B., Schmidberger, M., Daniell, J. E., Bedka, K. M., and Kunz, M.: Severe thunderstorms with large hail across Germany in June 2019, Weather, 76, 228–237, https://doi.org/10.1002/wea.3886, 2021. a, b
Zhang, F.: Dynamics and structure of mesoscale error covariance of a winter cyclone estimated through short-range ensemble forecasts, Mon. Weather Rev., 133, 2876–2893, https://doi.org/10.1175/MWR3009.1, 2005. a
Zhang, F., Bei, N., Rotunno, R., Snyder, C., and Epifanio, C. C.: Mesoscale Predictability of Moist Baroclinic Waves: Convection-Permitting Experiments and Multistage Error Growth Dynamics, J. Atmos. Sci., 64, 3579–3594, https://doi.org/10.1175/jas4028.1, 2007. a
Zhang, F., Sun, Y., Magnusson, L., Buizza, R., Lin, S., Chen, J., and Emanuel, K.: What Is the Predictability Limit of Midlatitude Weather?, J. Atmos. Sci., 76, 1077–1091, https://doi.org/10.1175/JAS-D-18-0269.1, 2019. a
Short summary
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.
Deep convective clouds (thunderstorms), which may cause severe weather, tend to coherently...
