Articles | Volume 5, issue 1
https://doi.org/10.5194/wcd-5-251-2024
© 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-5-251-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
20 Feb 2024
Research article |
| 20 Feb 2024
| 20 Feb 2024
Replicating the Hadley cell edge and subtropical jet latitude disconnect in idealized atmospheric models
NASA Goddard Institute for Space Studies, New York, New York, USA
Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland, USA
Darryn W. Waugh
Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland, USA
Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York (SUNY), Albany, New York, USA
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Thomas Reichler
Department of Atmospheric Sciences, University of Utah, Salt Lake City, Utah, USA
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Cristiana Stan, Saisri Kollapaneni, Andrea Jenney, Jiabao Wang, Zheng Wu, Cheng Zheng, Hyemi Kim, Chaim Garfinkel, and Ayush Singh
EGUsphere, https://doi.org/10.5194/egusphere-2025-1142, https://doi.org/10.5194/egusphere-2025-1142, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
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The MJO-Teleconnections diagnostics package is an open-source Python software package to be used for evaluation of MJO-Teleconnections predicted by subseasonal-to-seasonal (S2S) forecast systems.
Laurie C. Menviel, Paul Spence, Andrew E. Kiss, Matthew A. Chamberlain, Hakase Hayashida, Matthew H. England, and Darryn Waugh
Biogeosciences, 20, 4413–4431, https://doi.org/10.5194/bg-20-4413-2023, https://doi.org/10.5194/bg-20-4413-2023, 2023
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As the ocean absorbs 25% of the anthropogenic emissions of carbon, it is important to understand the impact of climate change on the flux of carbon between the ocean and the atmosphere. Here, we use a very high-resolution ocean, sea-ice, carbon cycle model to show that the capability of the Southern Ocean to uptake CO2 has decreased over the last 40 years due to a strengthening and poleward shift of the southern hemispheric westerlies. This trend is expected to continue over the coming century.
Daniel Baldassare, Thomas Reichler, Piret Plink-Björklund, and Jacob Slawson
Weather Clim. Dynam., 4, 531–541, https://doi.org/10.5194/wcd-4-531-2023, https://doi.org/10.5194/wcd-4-531-2023, 2023
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Using ensemble members from the ERA5 reanalysis, the most widely used method for estimating tropical-width trends, the meridional stream function, was found to have large error, particularly in the Northern Hemisphere and in the summer, because of weak gradients at the tropical edge and poor data quality. Another method, using the latitude where the surface wind switches from westerly to easterly, was found to have lower error due to better-observed data.
Raphaël de Fondeville, Zheng Wu, Enikő Székely, Guillaume Obozinski, and Daniela I. V. Domeisen
Weather Clim. Dynam., 4, 287–307, https://doi.org/10.5194/wcd-4-287-2023, https://doi.org/10.5194/wcd-4-287-2023, 2023
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We propose a fully data-driven, interpretable, and computationally scalable framework to characterize sudden stratospheric warmings (SSWs), extract statistically significant precursors, and produce machine learning (ML) forecasts. By successfully leveraging the long-lasting impact of SSWs, the ML predictions outperform sub-seasonal numerical forecasts for lead times beyond 25 d. Post-processing numerical predictions using their ML counterparts yields a performance increase of up to 20 %.
Nora Bergner, Marina Friedel, Daniela I. V. Domeisen, Darryn Waugh, and Gabriel Chiodo
Atmos. Chem. Phys., 22, 13915–13934, https://doi.org/10.5194/acp-22-13915-2022, https://doi.org/10.5194/acp-22-13915-2022, 2022
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Polar vortex extremes, particularly situations with an unusually weak cyclonic circulation in the stratosphere, can influence the surface climate in the spring–summer time in the Southern Hemisphere. Using chemistry-climate models and observations, we evaluate the robustness of the surface impacts. While models capture the general surface response, they do not show the observed climate patterns in midlatitude regions, which we trace back to biases in the models' circulations.
Rachel Wai-Ying Wu, Zheng Wu, and Daniela I.V. Domeisen
Weather Clim. Dynam., 3, 755–776, https://doi.org/10.5194/wcd-3-755-2022, https://doi.org/10.5194/wcd-3-755-2022, 2022
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Accurate predictions of the stratospheric polar vortex can enhance surface weather predictability. Stratospheric events themselves are less predictable, with strong inter-event differences. We assess the predictability of stratospheric acceleration and deceleration events in a sub-seasonal prediction system, finding that the predictability of events is largely dependent on event magnitude, while extreme drivers of deceleration events are not fully represented in the model.
Thomas Reichler and Martin Jucker
Weather Clim. Dynam., 3, 659–677, https://doi.org/10.5194/wcd-3-659-2022, https://doi.org/10.5194/wcd-3-659-2022, 2022
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Variations in the stratospheric polar vortex, so-called vortex events, can improve predictions of surface weather and climate. There are various ways to detect such events, and here we use the amount of wave energy that propagates into the stratosphere. The new definition is tested against so-called stratospheric sudden warmings (SSWs). We find that the wave definition has advantages over SSWs, for example in terms of a stronger surface response that follows the events.
Hao-Jhe Hong and Thomas Reichler
Geosci. Model Dev., 14, 6647–6660, https://doi.org/10.5194/gmd-14-6647-2021, https://doi.org/10.5194/gmd-14-6647-2021, 2021
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The Arctic wintertime circulation of the stratosphere has pronounced impacts on the troposphere and surface climate. Changes in the stratospheric circulation can lead to either increases or decreases in Arctic ozone. Understanding the interactions between ozone and the circulation will have the benefit of model prediction for the climate. This study introduces an economical and fast simplified model that represents the realistic distribution of ozone and its interaction with the circulation.
Zheng Wu, Bernat Jiménez-Esteve, Raphaël de Fondeville, Enikő Székely, Guillaume Obozinski, William T. Ball, and Daniela I. V. Domeisen
Weather Clim. Dynam., 2, 841–865, https://doi.org/10.5194/wcd-2-841-2021, https://doi.org/10.5194/wcd-2-841-2021, 2021
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We use an advanced statistical approach to investigate the dynamics of the development of sudden stratospheric warming (SSW) events in the winter Northern Hemisphere. We identify distinct signals that are representative of these events and their event type at lead times beyond currently predictable lead times. The results can be viewed as a promising step towards improving the predictability of SSWs in the future by using more advanced statistical methods in operational forecasting systems.
Alkuin Maximilian Koenig, Olivier Magand, Paolo Laj, Marcos Andrade, Isabel Moreno, Fernando Velarde, Grover Salvatierra, René Gutierrez, Luis Blacutt, Diego Aliaga, Thomas Reichler, Karine Sellegri, Olivier Laurent, Michel Ramonet, and Aurélien Dommergue
Atmos. Chem. Phys., 21, 3447–3472, https://doi.org/10.5194/acp-21-3447-2021, https://doi.org/10.5194/acp-21-3447-2021, 2021
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The environmental cycling of atmospheric mercury, a harmful global contaminant, is still not sufficiently constrained, partly due to missing data in remote regions. Here, we address this issue by presenting 20 months of atmospheric mercury measurements, sampled in the Bolivian Andes. We observe a significant seasonal pattern, whose key features we explore. Moreover, we deduce ratios to constrain South American biomass burning mercury emissions and the mercury uptake by the Amazon rainforest.
Hao-Jhe Hong and Thomas Reichler
Atmos. Chem. Phys., 21, 1159–1171, https://doi.org/10.5194/acp-21-1159-2021, https://doi.org/10.5194/acp-21-1159-2021, 2021
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Stratospheric ozone is a crucial chemical substance that protects life on Earth from harmful ultraviolet radiation. This article demonstrates how a strong or a weak Arctic polar vortex has an impact on wintertime circulation activity and the concentration of ozone in the stratosphere. Our results suggest that changes in the strength of the polar vortex lead to not only significant and persistent ozone changes locally in the Arctic but also to evident ozone changes in the tropics.
Clara Orbe, David A. Plummer, Darryn W. Waugh, Huang Yang, Patrick Jöckel, Douglas E. Kinnison, Beatrice Josse, Virginie Marecal, Makoto Deushi, Nathan Luke Abraham, Alexander T. Archibald, Martyn P. Chipperfield, Sandip Dhomse, Wuhu Feng, and Slimane Bekki
Atmos. Chem. Phys., 20, 3809–3840, https://doi.org/10.5194/acp-20-3809-2020, https://doi.org/10.5194/acp-20-3809-2020, 2020
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Atmospheric composition is strongly influenced by global-scale winds that are not always properly simulated in computer models. A common approach to correct for this bias is to relax or
nudgeto the observed winds. Here we systematically evaluate how well this technique performs across a large suite of chemistry–climate models in terms of its ability to reproduce key aspects of both the tropospheric and stratospheric circulations.
Huang Yang, Darryn W. Waugh, Clara Orbe, Guang Zeng, Olaf Morgenstern, Douglas E. Kinnison, Jean-Francois Lamarque, Simone Tilmes, David A. Plummer, Patrick Jöckel, Susan E. Strahan, Kane A. Stone, and Robyn Schofield
Atmos. Chem. Phys., 19, 5511–5528, https://doi.org/10.5194/acp-19-5511-2019, https://doi.org/10.5194/acp-19-5511-2019, 2019
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We evaluate the performance of a suite of models in simulating the large-scale transport from the northern midlatitudes to the Arctic using a CO-like idealized tracer. We find a large multi-model spread of the Arctic concentration of this CO-like tracer that is well correlated with the differences in the location of the midlatitude jet as well as the northern Hadley Cell edge. Our results suggest the Hadley Cell is key and zonal-mean transport by surface meridional flow needs better constraint.
Ori Adam, Kevin M. Grise, Paul Staten, Isla R. Simpson, Sean M. Davis, Nicholas A. Davis, Darryn W. Waugh, Thomas Birner, and Alison Ming
Geosci. Model Dev., 11, 4339–4357, https://doi.org/10.5194/gmd-11-4339-2018, https://doi.org/10.5194/gmd-11-4339-2018, 2018
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Due to incoherent methodologies, estimates of tropical width variations differ significantly across studies. Here, methods for eight commonly-used metrics of the tropical width are implemented in the Tropical-width Diagnostics (TropD) code package. The method compilation and analysis provide tools and information which help reduce the methodological component of the uncertainty associated with calculations of the tropical width.
Xiaokang Wu, Huang Yang, Darryn W. Waugh, Clara Orbe, Simone Tilmes, and Jean-Francois Lamarque
Atmos. Chem. Phys., 18, 7439–7452, https://doi.org/10.5194/acp-18-7439-2018, https://doi.org/10.5194/acp-18-7439-2018, 2018
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The seasonal and interannual variability of transport times from northern mid-latitudes into the southern hemisphere is examined using simulations of
agetracers. The largest variability occurs near the surface close to the tropical convergence zones, but the peak is further south and there is a smaller tropical–extratropical contrast for tracers with more rapid loss. Hence the variability of trace gases in the southern extratropics will vary with their chemical lifetime.
Clara Orbe, Huang Yang, Darryn W. Waugh, Guang Zeng, Olaf Morgenstern, Douglas E. Kinnison, Jean-Francois Lamarque, Simone Tilmes, David A. Plummer, John F. Scinocca, Beatrice Josse, Virginie Marecal, Patrick Jöckel, Luke D. Oman, Susan E. Strahan, Makoto Deushi, Taichu Y. Tanaka, Kohei Yoshida, Hideharu Akiyoshi, Yousuke Yamashita, Andreas Stenke, Laura Revell, Timofei Sukhodolov, Eugene Rozanov, Giovanni Pitari, Daniele Visioni, Kane A. Stone, Robyn Schofield, and Antara Banerjee
Atmos. Chem. Phys., 18, 7217–7235, https://doi.org/10.5194/acp-18-7217-2018, https://doi.org/10.5194/acp-18-7217-2018, 2018
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In this study we compare a few atmospheric transport properties among several numerical models that are used to study the influence of atmospheric chemistry on climate. We show that there are large differences among models in terms of the timescales that connect the Northern Hemisphere midlatitudes, where greenhouse gases and ozone-depleting substances are emitted, to the Southern Hemisphere. Our results may have important implications for how models represent atmospheric composition.
Olga V. Tweedy, Natalya A. Kramarova, Susan E. Strahan, Paul A. Newman, Lawrence Coy, William J. Randel, Mijeong Park, Darryn W. Waugh, and Stacey M. Frith
Atmos. Chem. Phys., 17, 6813–6823, https://doi.org/10.5194/acp-17-6813-2017, https://doi.org/10.5194/acp-17-6813-2017, 2017
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In this study we examined the impact of unprecedented disruption in the wind pattern (the quasi-biennial oscillation, or QBO) in the tropical stratosphere (16–48 km above the ground) on chemicals very important to the stratospheric climate such as ozone (O3). During the 2016 boreal summer, total O3 is lower in the extratropics than during previous QBO cycles due to lifting forced from the disruption. This decrease in O3 led to the increase in surface UV index by 8.5 % compared to the 36 yr mean.
Chaim I. Garfinkel, Valentina Aquila, Darryn W. Waugh, and Luke D. Oman
Atmos. Chem. Phys., 17, 1313–1327, https://doi.org/10.5194/acp-17-1313-2017, https://doi.org/10.5194/acp-17-1313-2017, 2017
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Previous work has noted a discrepancy between models and observations in trends of the large-scale overturning circulation in the stratosphere. Here, we show that a model can simulate trends that are reminiscent of those observed, including space- and time-varying trends in different regions of the stratosphere. We therefore clarify that the statement that is often made that models simulate an accelerated circulation only applies over long time periods and is not true for the past 25 years.
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Weather Clim. Dynam., 6, 369–385, https://doi.org/10.5194/wcd-6-369-2025, https://doi.org/10.5194/wcd-6-369-2025, 2025
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Hugo A. Braga and Victor Magaña
Weather Clim. Dynam., 6, 265–277, https://doi.org/10.5194/wcd-6-265-2025, https://doi.org/10.5194/wcd-6-265-2025, 2025
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This study presents a comprehensive dynamic and statistical analysis of mixed Rossby–gravity waves during the austral summer. It highlights the significant influence of upper-level lateral forcing on wave dynamics and the critical role of lower-tropospheric humidity in modulating asymmetric convection, providing new insights into the behavior of equatorial waves and their impact on regional weather patterns.
Quentin Nicolas and William R. Boos
Weather Clim. Dynam., 6, 231–244, https://doi.org/10.5194/wcd-6-231-2025, https://doi.org/10.5194/wcd-6-231-2025, 2025
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Rainfall in mountainous regions constitutes an important source of freshwater in the tropics. Yet how it will change with global warming remains an open question. Here, we reveal a strong sensitivity of this rainfall to the speed of prevailing winds. This relationship, validated by theory, simulations, and observational data, suggests that regional wind shifts will significantly influence future rainfall changes in the tropics.
Priya Bharati, Pranab Deb, and Kieran Mark Rainwater Hunt
Weather Clim. Dynam., 6, 197–210, https://doi.org/10.5194/wcd-6-197-2025, https://doi.org/10.5194/wcd-6-197-2025, 2025
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Our study highlights that the negative phase of the Pacific Decadal Oscillation (PDO) enhanced winter snowfall in the Karakoram and the Western Himalayas (KH) from 1940 to 2022. This is driven by deep convection, adiabatic cooling, and a wave-like atmospheric pattern linked to the subtropical jet (STJ). The PDO–STJ relationship offers insights into decadal snowfall predictability in KH, emphasizing the PDO's role in regional climate dynamics.
Matthias Fischer, Peter Knippertz, and Carsten Proppe
Weather Clim. Dynam., 6, 113–130, https://doi.org/10.5194/wcd-6-113-2025, https://doi.org/10.5194/wcd-6-113-2025, 2025
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The West African monsoon is vital for millions but difficult to represent with numerical models. Our research aims at improving monsoon simulations by optimizing three model parameters – entrainment rate, ice fall speed, and soil moisture evaporation – using an advanced surrogate-based multi-objective optimization framework. Results show that tuning these parameters can sometimes improve certain monsoon characteristics, however at the expense of others, highlighting the power of our approach.
Kieran M. R. Hunt, Jean-Philippe Baudouin, Andrew G. Turner, A. P. Dimri, Ghulam Jeelani, Pooja, Rajib Chattopadhyay, Forest Cannon, T. Arulalan, M. S. Shekhar, T. P. Sabin, and Eliza Palazzi
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Western disturbances (WDs) are storms that predominantly affect north India and Pakistan during the winter months, where they play an important role in regional water security, but can also bring a range of natural hazards. In this review, we summarise recent literature across a range of topics: their structure and lifecycle, precipitation and impacts, interactions with large-scale weather patterns, representation in models, how well they are forecast, and their response to changes in climate.
Aleena M. Jaison, Lesley J. Gray, Scott M. Osprey, Jeff R. Knight, and Martin B. Andrews
Weather Clim. Dynam., 5, 1489–1504, https://doi.org/10.5194/wcd-5-1489-2024, https://doi.org/10.5194/wcd-5-1489-2024, 2024
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Pep Cos, Matias Olmo, Diego Campos, Raül Marcos-Matamoros, Lluís Palma, Angel G. Muñoz, and Francisco J. Doblas-Reyes
EGUsphere, https://doi.org/10.5194/egusphere-2024-3331, https://doi.org/10.5194/egusphere-2024-3331, 2024
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Aude Garin, Francesco S. R. Pausata, Mathieu Boudreault, and Roberto Ingrosso
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Matthew Davison and Peter Haynes
Weather Clim. Dynam., 5, 1153–1185, https://doi.org/10.5194/wcd-5-1153-2024, https://doi.org/10.5194/wcd-5-1153-2024, 2024
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A simple model is used to study the relation between small-scale convection and large-scale variability in the tropics arising from the coupling between moisture and dynamics. In the model, moisture preferentially lies at either moist or dry states, which merge to form large-scale aggregated regions. On an equatorial β plane, these aggregated regions are localised at the Equator and propagate zonally. This forms an intermediate model between past simpler models and general circulation models.
Nicolás García-Lee, Claudio Bravo, Álvaro Gónzalez-Reyes, and Piero Mardones
Weather Clim. Dynam., 5, 1137–1151, https://doi.org/10.5194/wcd-5-1137-2024, https://doi.org/10.5194/wcd-5-1137-2024, 2024
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This study analyses the 0 °C isotherm in Patagonia from 1959 to 2021, using observational and fifth-generation European Centre for Medium-Range Weather Forecasts atmospheric reanalysis data. The model aligns well with observations, highlighting significant altitude variations between the western and eastern sides of the austral Andes, a correlation between isotherm fluctuations and the Southern Annular Mode index, and an upward trend in the study area (especially in northwestern Patagonia).
Ting-Yu Cha and Michael M. Bell
Weather Clim. Dynam., 5, 1013–1029, https://doi.org/10.5194/wcd-5-1013-2024, https://doi.org/10.5194/wcd-5-1013-2024, 2024
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Our study investigates the dynamics of polygonal eyewall structures observed in intensifying hurricanes like Michael (2018) by using a simplified modeling approach. We develop a two-layer model to simulate the interactions between the free atmosphere and boundary layer to demonstrate the importance of different physical mechanisms in the intensification process. This simplified model offers insights into the interactions between dynamics and convection during hurricane intensification.
Abu Bakar Siddiqui Thakur and Jai Sukhatme
Weather Clim. Dynam., 5, 839–862, https://doi.org/10.5194/wcd-5-839-2024, https://doi.org/10.5194/wcd-5-839-2024, 2024
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We analyze the present and future states of the tropical upper troposphere. Observations and climate model simulations suggest that interactions between disparate families of waves and the mean flow maintain present-day upper-level winds, and each component undergoes complex changes due to global warming. While the net east–west flow of the atmosphere may remain unaltered, this study indicates robust changes to local circulations that may influence tropical precipitation and regional climate.
Gill M. Martin and José M. Rodríguez
Weather Clim. Dynam., 5, 711–731, https://doi.org/10.5194/wcd-5-711-2024, https://doi.org/10.5194/wcd-5-711-2024, 2024
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Using sensitivity experiments, we show that model errors developing in the Maritime Continent region contribute substantially to the Asian summer monsoon (ASM) circulation and rainfall errors through their effects on the western North Pacific subtropical high-pressure region and the winds and sea surface temperatures in the equatorial Indian Ocean, exacerbated by local coupled feedback. Such information will inform future model developments aimed at improving model predictions for the ASM.
Clemens Spensberger
Weather Clim. Dynam., 5, 659–669, https://doi.org/10.5194/wcd-5-659-2024, https://doi.org/10.5194/wcd-5-659-2024, 2024
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It is well-established that variations in convection in the tropical Indo-Pacific can influence weather in far-away regions. In this idea, I argue that the main theory used to explain this influence over large distances is incomplete. I propose hypotheses that could lead the way towards a more fundamental explanation and outline a novel approach that could be used to test the hypotheses I raise. The suggested approach might be useful to address also other long-standing questions.
Richard J. Keane, Ankur Srivastava, and Gill M. Martin
Weather Clim. Dynam., 5, 671–702, https://doi.org/10.5194/wcd-5-671-2024, https://doi.org/10.5194/wcd-5-671-2024, 2024
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We evaluate the performance of two widely used models in forecasting the Indian summer monsoon, which is one of the most challenging meteorological phenomena to simulate. The work links previous studies evaluating the use of the models in weather forecasting and climate simulation, as the focus here is on seasonal forecasting, which involves intermediate timescales. As well as being important in itself, this evaluation provides insights into how errors develop in the two modelling systems.
Matthias Fischer, Peter Knippertz, Roderick van der Linden, Alexander Lemburg, Gregor Pante, Carsten Proppe, and John H. Marsham
Weather Clim. Dynam., 5, 511–536, https://doi.org/10.5194/wcd-5-511-2024, https://doi.org/10.5194/wcd-5-511-2024, 2024
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Our research enhances the understanding of the complex dynamics within the West African monsoon system by analyzing the impact of specific model parameters on its characteristics. Employing surrogate models, we identified critical factors such as the entrainment rate and the fall velocity of ice. Precise definition of these parameters in weather models could improve forecast accuracy, thus enabling better strategies to manage and reduce the impact of weather events.
Kieran M. R. Hunt
Weather Clim. Dynam., 5, 345–356, https://doi.org/10.5194/wcd-5-345-2024, https://doi.org/10.5194/wcd-5-345-2024, 2024
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This study investigates changes in weather systems that bring winter precipitation to south Asia. We find that these systems, known as western disturbances, are occurring more frequently and lasting longer into the summer months. This shift is leading to devastating floods, as happened recently in north India. By analysing 70 years of weather data, we trace this change to shifts in major air currents known as the subtropical jet. Due to climate change, such events are becoming more frequent.
William J. Dow, Christine M. McKenna, Manoj M. Joshi, Adam T. Blaker, Richard Rigby, and Amanda C. Maycock
Weather Clim. Dynam., 5, 357–367, https://doi.org/10.5194/wcd-5-357-2024, https://doi.org/10.5194/wcd-5-357-2024, 2024
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Changes to sea surface temperatures in the extratropical North Pacific are driven partly by patterns of local atmospheric circulation, such as the Aleutian Low. We show that an intensification of the Aleutian Low could contribute to small changes in temperatures across the equatorial Pacific via the initiation of two mechanisms. The effect, although significant, is unlikely to explain fully the recently observed multi-year shift of a pattern of climate variability across the wider Pacific.
Franco Molteni, Fred Kucharski, and Riccardo Farneti
Weather Clim. Dynam., 5, 293–322, https://doi.org/10.5194/wcd-5-293-2024, https://doi.org/10.5194/wcd-5-293-2024, 2024
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We describe some new features of an intermediate-complexity coupled model, including a three-layer thermodynamic ocean model suitable to explore the extratropical response to tropical ocean variability. We present results on the model climatology and show that important features of interdecadal and interannual variability are realistically simulated in a
pacemakercoupled ensemble of 70-year runs, where portions of the tropical Indo-Pacific are constrained to follow the observed variability.
Julian F. Quinting, Christian M. Grams, Edmund Kar-Man Chang, Stephan Pfahl, and Heini Wernli
Weather Clim. Dynam., 5, 65–85, https://doi.org/10.5194/wcd-5-65-2024, https://doi.org/10.5194/wcd-5-65-2024, 2024
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Research in the last few decades has revealed that rapidly ascending airstreams in extratropical cyclones have an important effect on the evolution of downstream weather and predictability. In this study, we show that the occurrence of these airstreams over the North Pacific is modulated by tropical convection. Depending on the modulation, known atmospheric circulation patterns evolve quite differently, which may affect extended-range predictions in the Atlantic–European region.
Hyunju Jung, Peter Knippertz, Yvonne Ruckstuhl, Robert Redl, Tijana Janjic, and Corinna Hoose
Weather Clim. Dynam., 4, 1111–1134, https://doi.org/10.5194/wcd-4-1111-2023, https://doi.org/10.5194/wcd-4-1111-2023, 2023
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A narrow rainfall belt in the tropics is an important feature for large-scale circulations and the global water cycle. The accurate simulation of this rainfall feature has been a long-standing problem, with the reasons behind that unclear. We present a novel diagnostic tool that allows us to disentangle processes important for rainfall, which changes due to modifications in model. Using our diagnostic tool, one can potentially identify sources of uncertainty in weather and climate models.
Lina Boljka, Nour-Eddine Omrani, and Noel S. Keenlyside
Weather Clim. Dynam., 4, 1087–1109, https://doi.org/10.5194/wcd-4-1087-2023, https://doi.org/10.5194/wcd-4-1087-2023, 2023
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This study examines quasi-periodic variability in the tropical Pacific on interannual timescales and related physics using a recently developed time series analysis tool. We find that wind stress in the west Pacific and recharge–discharge of ocean heat content are likely related to each other on ~1.5–4.5-year timescales (but not on others) and dominate variability in sea surface temperatures on those timescales. This may have further implications for climate models and long-term prediction.
Sam Hardy, John Methven, Juliane Schwendike, Ben Harvey, and Mike Cullen
Weather Clim. Dynam., 4, 1019–1043, https://doi.org/10.5194/wcd-4-1019-2023, https://doi.org/10.5194/wcd-4-1019-2023, 2023
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We examine a Borneo vortex case using computer simulations and satellite observations. The vortex is identified with high humidity through the atmosphere and has heaviest rainfall on its northern flank. Simulations represent circulation and rainfall accumulation well. The low-level Borneo vortex is coupled with a higher-level wave, which moves westwards along a layer with a sharp vertical gradient in moisture. Vortex growth occurs through mechanisms usually considered outside the tropics.
Chiem van Straaten, Dim Coumou, Kirien Whan, Bart van den Hurk, and Maurice Schmeits
Weather Clim. Dynam., 4, 887–903, https://doi.org/10.5194/wcd-4-887-2023, https://doi.org/10.5194/wcd-4-887-2023, 2023
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Variability in the tropics can influence weather over Europe. This study evaluates a summertime connection between the two. It shows that strongly opposing west Pacific sea surface temperature anomalies have occurred more frequently since 1980, likely due to a combination of long-term warming in the west Pacific and the El Niño Southern Oscillation. Three to six weeks later, the distribution of hot and cold airmasses over Europe is affected.
Francis Nkrumah, Cornelia Klein, Kwesi Akumenyi Quagraine, Rebecca Berkoh-Oforiwaa, Nana Ama Browne Klutse, Patrick Essien, Gandomè Mayeul Leger Davy Quenum, and Hubert Azoda Koffi
Weather Clim. Dynam., 4, 773–788, https://doi.org/10.5194/wcd-4-773-2023, https://doi.org/10.5194/wcd-4-773-2023, 2023
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It is not yet clear which variations in broader atmospheric conditions of the West African monsoon may lead to mesoscale convective system (MCS) occurrences in southern West Africa (SWA). In this study, we identified nine different weather patterns and categorized them as dry-, transition-, or monsoon-season types using a method called self-organizing maps (SOMs). It was revealed that a warmer Sahel region can create favourable conditions for MCS formation in SWA.
Giorgia Di Capua, Dim Coumou, Bart van den Hurk, Antje Weisheimer, Andrew G. Turner, and Reik V. Donner
Weather Clim. Dynam., 4, 701–723, https://doi.org/10.5194/wcd-4-701-2023, https://doi.org/10.5194/wcd-4-701-2023, 2023
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Heavy rainfall in tropical regions interacts with mid-latitude circulation patterns, and this interaction can explain weather patterns in the Northern Hemisphere during summer. In this analysis we detect these tropical–extratropical interaction pattern both in observational datasets and data obtained by atmospheric models and assess how well atmospheric models can reproduce the observed patterns. We find a good agreement although these relationships are weaker in model data.
Daniel Baldassare, Thomas Reichler, Piret Plink-Björklund, and Jacob Slawson
Weather Clim. Dynam., 4, 531–541, https://doi.org/10.5194/wcd-4-531-2023, https://doi.org/10.5194/wcd-4-531-2023, 2023
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Using ensemble members from the ERA5 reanalysis, the most widely used method for estimating tropical-width trends, the meridional stream function, was found to have large error, particularly in the Northern Hemisphere and in the summer, because of weak gradients at the tropical edge and poor data quality. Another method, using the latitude where the surface wind switches from westerly to easterly, was found to have lower error due to better-observed data.
Nele Tim, Eduardo Zorita, Birgit Hünicke, and Ioana Ivanciu
Weather Clim. Dynam., 4, 381–397, https://doi.org/10.5194/wcd-4-381-2023, https://doi.org/10.5194/wcd-4-381-2023, 2023
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As stated by the IPCC, southern Africa is one of the two land regions that are projected to suffer from the strongest precipitation reductions in the future. Simulated drying in this region is linked to the adjacent oceans, and prevailing winds as warm and moist air masses are transported towards the continent. Precipitation trends in past and future climate can be partly attributed to the strength of the Agulhas Current system, the current along the east and south coasts of southern Africa.
William Torgerson, Juliane Schwendike, Andrew Ross, and Chris J. Short
Weather Clim. Dynam., 4, 331–359, https://doi.org/10.5194/wcd-4-331-2023, https://doi.org/10.5194/wcd-4-331-2023, 2023
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We investigated intensity fluctuations that occurred during the rapid intensification of Hurricane Irma (2017) to understand their effects on the storm structure. Using high-resolution model simulations, we found that the fluctuations were caused by local regions of strong ascent just outside the eyewall that disrupted the storm, leading to a larger and more symmetrical storm eye. This alters the location and intensity of the strongest winds in the storm and hence the storm's impact.
Anne Martin, Martin Weissmann, and Alexander Cress
Weather Clim. Dynam., 4, 249–264, https://doi.org/10.5194/wcd-4-249-2023, https://doi.org/10.5194/wcd-4-249-2023, 2023
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Global wind profiles from the Aeolus satellite mission are an important recent substitute for the Global Observing System, showing an overall positive impact on numerical weather prediction forecasts. This study highlights atmospheric dynamic phenomena constituting pathways for significant improvement of Aeolus for future studies, including large-scale tropical circulation systems and the interaction of tropical cyclones undergoing an extratropical transition with the midlatitude waveguide.
Elliott Michael Sainsbury, Reinhard K. H. Schiemann, Kevin I. Hodges, Alexander J. Baker, Len C. Shaffrey, Kieran T. Bhatia, and Stella Bourdin
Weather Clim. Dynam., 3, 1359–1379, https://doi.org/10.5194/wcd-3-1359-2022, https://doi.org/10.5194/wcd-3-1359-2022, 2022
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Post-tropical cyclones (PTCs) can bring severe weather to Europe. By tracking and identifying PTCs in five global climate models, we investigate how the frequency and intensity of PTCs may change across Europe by 2100. We find no robust change in the frequency or intensity of Europe-impacting PTCs in the future. This study indicates that large uncertainties surround future Europe-impacting PTCs and provides a framework for evaluating PTCs in future generations of climate models.
Kieran M. R. Hunt and Andrew G. Turner
Weather Clim. Dynam., 3, 1341–1358, https://doi.org/10.5194/wcd-3-1341-2022, https://doi.org/10.5194/wcd-3-1341-2022, 2022
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More than half of India's summer monsoon rainfall arises from low-pressure systems: storms originating over the Bay of Bengal. In observation-based data, we examine how the generation and pathway of these storms are changed by the
boreal summer intraseasonal oscillation– the chief means of large-scale control on the monsoon at timescales of a few weeks. Our study offers new insights for useful prediction of these storms, important for both water resources planning and disaster early warning.
Cornelius Immanuel Weiß, Alexander Gohm, Mathias Walter Rotach, and Thomas Torora Minda
Weather Clim. Dynam., 3, 1003–1019, https://doi.org/10.5194/wcd-3-1003-2022, https://doi.org/10.5194/wcd-3-1003-2022, 2022
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Two gap flow events in the Great Rift Valley in Ethiopia were investigated based on observations, ERA5 reanalysis data, and simulations with the numerical weather prediction model WRF. The main focus was on strong winds in the area around Lake Abaya since the winds may generate waves on the lake which help to sustain the lake's ecology. That is important in terms of food supply for the local population. The gap winds exhibit a diurnal cycle and a seasonal dependence.
Matic Pikovnik, Žiga Zaplotnik, Lina Boljka, and Nedjeljka Žagar
Weather Clim. Dynam., 3, 625–644, https://doi.org/10.5194/wcd-3-625-2022, https://doi.org/10.5194/wcd-3-625-2022, 2022
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Potential future changes in the Hadley cells (HCs), either to their strength or their meridional extent, will profoundly impact the global distribution of precipitation. Therefore, to objectively evaluate and inter-compare past and future changes in the overall HC strength between different studies, a unified metric is required. The study proposes two new metrics, which alleviate the spatial inhomogeneities of the HC strength trend.
Ambrogio Volonté, Andrew G. Turner, Reinhard Schiemann, Pier Luigi Vidale, and Nicholas P. Klingaman
Weather Clim. Dynam., 3, 575–599, https://doi.org/10.5194/wcd-3-575-2022, https://doi.org/10.5194/wcd-3-575-2022, 2022
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In this study we analyse the complex seasonal evolution of the East Asian summer monsoon. Using reanalysis data, we show the importance of the interaction between tropical and extratropical air masses converging at the monsoon front, particularly during its northward progression. The upper-level flow pattern (e.g. the westerly jet) controls the balance between the airstreams and thus the associated rainfall. This framework provides a basis for studies of extreme events and climate variability.
Peter Pfleiderer, Shruti Nath, and Carl-Friedrich Schleussner
Weather Clim. Dynam., 3, 471–482, https://doi.org/10.5194/wcd-3-471-2022, https://doi.org/10.5194/wcd-3-471-2022, 2022
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Tropical cyclones are amongst the most dangerous weather events. Here we develop an empirical model that allows us to estimate the number and strengths of tropical cyclones for given atmospheric conditions and sea surface temperatures. An application of the model shows that atmospheric circulation is the dominant factor for seasonal tropical cyclone activity. However, warming sea surface temperatures have doubled the likelihood of extremely active hurricane seasons in the past decades.
Jean-Philippe Baudouin, Michael Herzog, and Cameron A. Petrie
Weather Clim. Dynam., 2, 1187–1207, https://doi.org/10.5194/wcd-2-1187-2021, https://doi.org/10.5194/wcd-2-1187-2021, 2021
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Western disturbances are mid-latitude, high-altitude, low-pressure areas that bring orographic precipitation into the Upper Indus Basin. Using statistical tools, we show that the interaction between western disturbances and relief explains the near-surface, cross-barrier wind activity. We also reveal the existence of a moisture pathway from the nearby seas. Overall, we offer a conceptual framework for western-disturbance activity, particularly in terms of precipitation.
Anantha Aiyyer and Terrell Wade
Weather Clim. Dynam., 2, 1051–1072, https://doi.org/10.5194/wcd-2-1051-2021, https://doi.org/10.5194/wcd-2-1051-2021, 2021
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We diagnose the mean circulations in the extratropics that are associated with rapid changes in the tropical storm storm speeds in the Atlantic. We show that rapid acceleration and deceleration are associated with distinct phasing between the tropical cyclone and weather waves of the extratropics. Over the past 5 decades, rapid acceleration and deceleration of tropical cyclones have reduced in magnitude. This might be related to the poleward shift and weakening of these extratropical waves.
Julianna Carvalho-Oliveira, Leonard Friedrich Borchert, Aurélie Duchez, Mikhail Dobrynin, and Johanna Baehr
Weather Clim. Dynam., 2, 739–757, https://doi.org/10.5194/wcd-2-739-2021, https://doi.org/10.5194/wcd-2-739-2021, 2021
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This work questions the influence of the Atlantic Meridional Overturning Circulation, an important component of the climate system, on the variability in North Atlantic sea surface temperature (SST) a season ahead, particularly how this influence affects SST prediction credibility 2–4 months into the future. While we find this relationship is relevant for assessing SST predictions, it strongly depends on the time period and season we analyse and is more subtle than what is found in observations.
Andrea M. Jenney, David A. Randall, and Elizabeth A. Barnes
Weather Clim. Dynam., 2, 653–673, https://doi.org/10.5194/wcd-2-653-2021, https://doi.org/10.5194/wcd-2-653-2021, 2021
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Storm activity in the tropics is one of the key phenomena that provide weather predictability on an extended timescale of about 10–40 d. The influence of tropical storminess on places like North America is sensitive to the overall average state of the climate system. In this study, we try to unpack the reasons why climate models do not agree on how the influence of these storms on weather over the North Pacific and North America will change in the future.
Philip Rupp and Peter Haynes
Weather Clim. Dynam., 2, 413–431, https://doi.org/10.5194/wcd-2-413-2021, https://doi.org/10.5194/wcd-2-413-2021, 2021
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We study a range of dynamical aspects of the Asian monsoon anticyclone as the response of a simple numerical model to a steady imposed heating distribution with different background flow configurations. Particular focus is given on interactions between the monsoon anticyclone and active mid-latitude dynamics, which we find to have a zonally localising effect on the time-mean circulation and to be able to qualitatively alter the temporal variability of the bulk anticyclone.
Joshua White and Anantha Aiyyer
Weather Clim. Dynam., 2, 311–329, https://doi.org/10.5194/wcd-2-311-2021, https://doi.org/10.5194/wcd-2-311-2021, 2021
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Using a simple general circulation model, we examine the structure of waves in the mid-tropospheric jet over North Africa. We show that waves occur in near-stationary groups or wave packets. As they are not swept out of the jet, this may provide the opportunity for the packets to amplify via feedback from other energy sources like rain-producing cloud complexes and mineral dust that are known to operate here. Our results address the criticism that the easterly jet is too short to sustain waves.
Franziska Aemisegger, Raphaela Vogel, Pascal Graf, Fabienne Dahinden, Leonie Villiger, Friedhelm Jansen, Sandrine Bony, Bjorn Stevens, and Heini Wernli
Weather Clim. Dynam., 2, 281–309, https://doi.org/10.5194/wcd-2-281-2021, https://doi.org/10.5194/wcd-2-281-2021, 2021
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The interaction of clouds in the trade wind region with the atmospheric flow is complex and at the heart of uncertainties associated with climate projections. In this study, a natural tracer of atmospheric circulation is used to establish a link between air originating from dry regions of the midlatitudes and the occurrence of specific cloud patterns. Two pathways involving transport within midlatitude weather systems are identified, by which air is brought into the trades within 5–10 d.
Jack Giddings, Adrian J. Matthews, Nicholas P. Klingaman, Karen J. Heywood, Manoj Joshi, and Benjamin G. M. Webber
Weather Clim. Dynam., 1, 635–655, https://doi.org/10.5194/wcd-1-635-2020, https://doi.org/10.5194/wcd-1-635-2020, 2020
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The impact of chlorophyll on the southwest monsoon is unknown. Here, seasonally varying chlorophyll in the Bay of Bengal was imposed in a general circulation model coupled to an ocean mixed layer model. The SST increases by 0.5 °C in response to chlorophyll forcing and shallow mixed layer depths in coastal regions during the inter-monsoon. Precipitation increases significantly to 3 mm d-1 across Myanmar during June and over northeast India and Bangladesh during October, decreasing model bias.
Giorgia Di Capua, Jakob Runge, Reik V. Donner, Bart van den Hurk, Andrew G. Turner, Ramesh Vellore, Raghavan Krishnan, and Dim Coumou
Weather Clim. Dynam., 1, 519–539, https://doi.org/10.5194/wcd-1-519-2020, https://doi.org/10.5194/wcd-1-519-2020, 2020
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We study the interactions between the tropical convective activity and the mid-latitude circulation in the Northern Hemisphere during boreal summer. We identify two circumglobal wave patterns with phase shifts corresponding to the South Asian and the western North Pacific monsoon systems at an intra-seasonal timescale. These patterns show two-way interactions in a causal framework at a weekly timescale and assess how El Niño affects these interactions.
Benjamin A. Stephens and Charles S. Jackson
Weather Clim. Dynam., 1, 389–404, https://doi.org/10.5194/wcd-1-389-2020, https://doi.org/10.5194/wcd-1-389-2020, 2020
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We analyze abrupt transitions between tropical rainfall regimes in a single-column model (SCM) of the tropical atmosphere. Multiple equilibria have been observed before in SCMs, but here we analyze actual bifurcations. We attribute the transitions to a sudden loss of evaporative cooling in the lower column due to nonlinearities in microphysics. This study may have implications for atmospheric dynamics more broadly but also for understanding abrupt transitions in paleoclimate.
Jorge L. García-Franco, Lesley J. Gray, and Scott Osprey
Weather Clim. Dynam., 1, 349–371, https://doi.org/10.5194/wcd-1-349-2020, https://doi.org/10.5194/wcd-1-349-2020, 2020
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The American monsoon system is the main source of rainfall for the subtropical Americas and an important element of Latin American agriculture. Here we use state-of-the-art climate models from the UK Met Office in different configurations to analyse the performance of these models in the American monsoon. Resolution is found to be a key factor to improve monsoon representation, whereas integrated chemistry does not improve the simulated monsoon rainfall.
Cited articles
Adam, O.: TropD: Tropical width diagnostics software package, Zenodo [code], https://doi.org/10.5281/zenodo.1413330, 2018.
Adam, O., Grise, K. M., Staten, P., Simpson, I. R., Davis, S. M., Davis, N. A., Waugh, D. W., Birner, T., and Ming, A.: The TropD software package (v1): standardized methods for calculating tropical-width diagnostics, Geosci. Model Dev., 11, 4339–4357, https://doi.org/10.5194/gmd-11-4339-2018, 2018. a, b
Cinquini, L., Crichton, D., Mattmann, C., Harney, J., Shipman, G., Wang, F., Ananthakrishnan, R., Miller, N., Denvil, S., Morgan, M., Pobre, Z., Bell, G. M., Doutriaux, C., Drach, R., Williams, D., Kershaw, P., Pascoe, S., Gonzalez, E., Fiore, S., and Schweitzer, R.: The Earth System Grid Federation: An open infrastructure for access to distributed geospatial data, Future Gener. Comp. Sy., 36, 400–417, https://doi.org/10.1016/j.future.2013.07.002, 2014 (data available at: https://esgf-node.llnl.gov).
Davis, N. A. and Birner, T.: Seasonal to multidecadal variability of the width of the tropical belt, J. Geophys. Res.-Atmos., 118, 7773–7787, 2013. a
Davis, N. A., Seidel, D. J., Birner, T., Davis, S. M., and Tilmes, S.: Changes in the width of the tropical belt due to simple radiative forcing changes in the GeoMIP simulations, Atmos. Chem. Phys., 16, 10083–10095, https://doi.org/10.5194/acp-16-10083-2016, 2016. a
Davis, S. M. and Rosenlof, K. H.: A multidiagnostic intercomparison of tropical-width time series using reanalyses and satellite observations, J. Climate, 25, 1061–1078, 2012. a
Eichelberger, S. J. and Hartmann, D. L.: Zonal jet structure and the leading mode of variability, J. Climate, 20, 5149–5163, 2007. a
Fujiwara, M., Wright, J. S., Manney, G. L., Gray, L. J., Anstey, J., Birner, T., Davis, S., Gerber, E. P., Harvey, V. L., Hegglin, M. I., Homeyer, C. R., Knox, J. A., Krüger, K., Lambert, A., Long, C. S., Martineau, P., Molod, A., Monge-Sanz, B. M., Santee, M. L., Tegtmeier, S., Chabrillat, S., Tan, D. G. H., Jackson, D. R., Polavarapu, S., Compo, G. P., Dragani, R., Ebisuzaki, W., Harada, Y., Kobayashi, C., McCarty, W., Onogi, K., Pawson, S., Simmons, A., Wargan, K., Whitaker, J. S., and Zou, C.-Z.: Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems, Atmos. Chem. Phys., 17, 1417–1452, https://doi.org/10.5194/acp-17-1417-2017, 2017. 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. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020. a
Jucker, M., Fueglistaler, S., and Vallis, G. K.: Stratospheric sudden warmings in an idealized GCM, J. Geophys. Res.-Atmos., 119, 11–054, 2014. a
Kobayashi, S., Ota, Y., Harada, Y., Ebita, A., Moriya, M., Onoda, H., Onogi, K., Kamahori, H., Kobayashi, C., Endo, H., Miyaoka, K., and Takahashi, K.: The JRA-55 reanalysis: General specifications and basic characteristics, J. Meteorol. Soc. Jpn. Ser. II, 93, 5–48, 2015. a
Korty, R. L. and Schneider, T.: Extent of Hadley circulations in dry atmospheres, Geophys. Res. Lett., 35, 23, https://doi.org/10.1029/2008GL03584, 2008. a, b, c
Lindzen, R. S. and Hou, A. V.: Hadley circulations for zonally averaged heating centered off the equator, J. Atmos. Sci., 45, 2416–2427, 1988. a
Lorenz, E.: The nature and theory of the general circulation of the atmosphere, World Meteorological Organization, Geneva, Switzerland, 161, 1967. a
Maher, P., Kelleher, M. E., Sansom, P. G., and Methven, J.: Is the subtropical jet shifting poleward?, Clim. Dynam., 54, 1741–1759, 2020. a
Martineau, P., Wright, J. S., Zhu, N., and Fujiwara, M.: Zonal-mean data set of global atmospheric reanalyses on pressure levels, Earth Syst. Sci. Data, 10, 1925–1941, https://doi.org/10.5194/essd-10-1925-2018, 2018 (data available at: https://s-rip.github.io/resources/data.html).
Menzel, M. E., Waugh, D. W., and Orbe, C.: Connections between Upper Tropospheric and Lower Stratospheric Circulation Responses to Increased CO2, J. Climate, 36, 4101–4112, 2023. a
Menzel, M. E., Waugh, D. W., Wu, Z., and Reichler, T.: Replicating the Hadley cell edge and subtropical jet latitude disconnect in idealized atmospheric models, Zenodo [data set], https://doi.org/10.5281/zenodo.8144564, 2024.
Shepherd, T. G. and McLandress, C.: A robust mechanism for strengthening of the Brewer–Dobson circulation in response to climate change: Critical-layer control of subtropical wave breaking, J. Atmos. Sci., 68, 784–797, 2011. a
Solomon, A., Polvani, L. M., Waugh, D. W., and Davis, S. M.: Contrasting upper and lower atmospheric metrics of tropical expansion in the395 Southern Hemisphere, Geophys. Res. Lett., 43, 10496–10503, https://doi.org/10.1002/2016GL070917, 2016. a, b, c
Sun, L., Chen, G., and Lu, J.: Sensitivities and mechanisms of the zonal mean atmospheric circulation response to tropical warming, J. Atmos. Sci., 70, 2487–2504, 2013. a
Taylor, K. E., Stouffer, R. J., and Meehl, G. A.: An overview of CMIP5 and the experiment design, B. Am. Meteorol. Soc., 93, 485–498, 2012. a
Vallis, G. K.: Atmospheric and oceanic fluid dynamics, Cambridge University Press, Cambridge, U.K., 2nd edn., https://doi.org/10.1017/9781107588417, 2017. a
Wu, Z. and Reichler, T.: Towards a More Earth-Like Circulation in Idealized Models, J. Adv. Model. Earth Sy., 10, 1458–1469, https://doi.org/10.1029/2018MS001356, 2018 (code available at: https://github.com/ZhengWinnieWu/WR_simpleGCM). a, b
Short summary
Recent work exploring the tropical atmospheric circulation response to climate change has revealed a disconnect in the latitudinal location of two features, the subtropical jet and the Hadley cell edge. Here, we investigate if the surprising result from coupled climate model and meteorological reanalysis output is consistent across model complexity.
Recent work exploring the tropical atmospheric circulation response to climate change has...
