Articles | Volume 3, issue 4
https://doi.org/10.5194/wcd-3-1399-2022
© Author(s) 2022. 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-3-1399-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Dec 2022
Research article |
| 01 Dec 2022
| 01 Dec 2022
Signatures of Eurasian heat waves in global Rossby wave spectra
Iana Strigunova
CORRESPONDING AUTHOR
Meteorological Institute, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, Grindelberg 5, 20144 Hamburg, Germany
Richard Blender
Meteorological Institute, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, Grindelberg 5, 20144 Hamburg, Germany
Frank Lunkeit
Meteorological Institute, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, Grindelberg 5, 20144 Hamburg, Germany
Nedjeljka Žagar
Meteorological Institute, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, Grindelberg 5, 20144 Hamburg, Germany
Related authors
Iana Strigunova, Frank Lunkeit, Nedjeljka Žagar, and Damjan Jelić
EGUsphere, https://doi.org/10.5194/egusphere-2025-892, https://doi.org/10.5194/egusphere-2025-892, 2025
Short summary
Short summary
Our study builds on previous research by examining how climate models simulate the large-scale Rossby wave circulation during present-day Eurasian heat waves (EHWs) and how it alters in the future. We find no increase in future frequency for EHWs defined with respect to the simulated mean climate. The models capture the averaged atmospheric circulation during EHWs but struggle with daily variability. Our results highlight the need for improvements to enhance predictions of extreme weather.
Danilo Custódio, Katrine Aspmo Pfaffhuber, T. Gerard Spain, Fidel F. Pankratov, Iana Strigunova, Koketso Molepo, Henrik Skov, Johannes Bieser, and Ralf Ebinghaus
Atmos. Chem. Phys., 22, 3827–3840, https://doi.org/10.5194/acp-22-3827-2022, https://doi.org/10.5194/acp-22-3827-2022, 2022
Short summary
Short summary
As a poison in the air that we breathe and the food that we eat, mercury is a human health concern for society as a whole. In that regard, this work deals with monitoring and modelling mercury in the environment, improving wherewithal, identifying the strength of the different components at play, and interpreting information to support the efforts that seek to safeguard public health.
Iana Strigunova, Frank Lunkeit, Nedjeljka Žagar, and Damjan Jelić
EGUsphere, https://doi.org/10.5194/egusphere-2025-892, https://doi.org/10.5194/egusphere-2025-892, 2025
Short summary
Short summary
Our study builds on previous research by examining how climate models simulate the large-scale Rossby wave circulation during present-day Eurasian heat waves (EHWs) and how it alters in the future. We find no increase in future frequency for EHWs defined with respect to the simulated mean climate. The models capture the averaged atmospheric circulation during EHWs but struggle with daily variability. Our results highlight the need for improvements to enhance predictions of extreme weather.
Rémy Asselot, Philip B. Holden, Frank Lunkeit, and Inga Hense
Earth Syst. Dynam., 15, 875–891, https://doi.org/10.5194/esd-15-875-2024, https://doi.org/10.5194/esd-15-875-2024, 2024
Short summary
Short summary
Phytoplankton are tiny oceanic algae able to absorb the light penetrating the ocean. The light absorbed by these organisms is re-emitted as heat in the surrounding environment, a process commonly called phytoplankton light absorption (PLA). As a consequence, PLA increases the oceanic temperature. We studied this mechanism with a climate model under different climate scenarios. We show that phytoplankton light absorption is reduced under strong warming scenarios, limiting oceanic warming.
Yuan-Bing Zhao, Nedjeljka Žagar, Frank Lunkeit, and Richard Blender
Weather Clim. Dynam., 4, 833–852, https://doi.org/10.5194/wcd-4-833-2023, https://doi.org/10.5194/wcd-4-833-2023, 2023
Short summary
Short summary
Coupled climate models have significant biases in the tropical Indian Ocean (TIO) sea surface temperature (SST). Our study shows that the TIO SST biases can affect the simulated global atmospheric circulation and its spatio-temporal variability on large scales. The response of the spatial variability is related to the amplitude or phase of the circulation bias, depending on the flow regime and spatial scale, while the response of the interannual variability depends on the sign of the SST bias.
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
Short summary
Short summary
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.
Miriam D'Errico, Flavio Pons, Pascal Yiou, Soulivanh Tao, Cesare Nardini, Frank Lunkeit, and Davide Faranda
Earth Syst. Dynam., 13, 961–992, https://doi.org/10.5194/esd-13-961-2022, https://doi.org/10.5194/esd-13-961-2022, 2022
Short summary
Short summary
Climate change is already affecting weather extremes. In a warming climate, we will expect the cold spells to decrease in frequency and intensity. Our analysis shows that the frequency of circulation patterns leading to snowy cold-spell events over Italy will not decrease under business-as-usual emission scenarios, although the associated events may not lead to cold conditions in the warmer scenarios.
Danilo Custódio, Katrine Aspmo Pfaffhuber, T. Gerard Spain, Fidel F. Pankratov, Iana Strigunova, Koketso Molepo, Henrik Skov, Johannes Bieser, and Ralf Ebinghaus
Atmos. Chem. Phys., 22, 3827–3840, https://doi.org/10.5194/acp-22-3827-2022, https://doi.org/10.5194/acp-22-3827-2022, 2022
Short summary
Short summary
As a poison in the air that we breathe and the food that we eat, mercury is a human health concern for society as a whole. In that regard, this work deals with monitoring and modelling mercury in the environment, improving wherewithal, identifying the strength of the different components at play, and interpreting information to support the efforts that seek to safeguard public health.
Rémy Asselot, Frank Lunkeit, Philip B. Holden, and Inga Hense
Biogeosciences, 19, 223–239, https://doi.org/10.5194/bg-19-223-2022, https://doi.org/10.5194/bg-19-223-2022, 2022
Short summary
Short summary
Previous studies show that phytoplankton light absorption can warm the atmosphere, but how this warming occurs is still unknown. We compare the importance of air–sea heat versus CO2 flux in the phytoplankton-induced atmospheric warming and determine the main driver. To shed light on this research question, we conduct simulations with a climate model of intermediate complexity. We show that phytoplankton mainly warms the atmosphere by increasing the air–sea CO2 flux.
Rémy Asselot, Frank Lunkeit, Philip Holden, and Inga Hense
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2021-91, https://doi.org/10.5194/esd-2021-91, 2021
Revised manuscript not accepted
Short summary
Short summary
Phytoplankton absorbing light can influence the climate system but its future effect on the climate is still unclear. We use a climate model to investigate the role of phytoplankton light absorption under global warming. We find out that the effect of phytoplankton light absorption is smaller under a high greenhouse gas emissions compared to reduced and intermediate greenhouse gas emissions. Additionally, we show that phytoplankton light absorption is an important mechanism for the carbon cycle.
Woon Mi Kim, Richard Blender, Michael Sigl, Martina Messmer, and Christoph C. Raible
Clim. Past, 17, 2031–2053, https://doi.org/10.5194/cp-17-2031-2021, https://doi.org/10.5194/cp-17-2031-2021, 2021
Short summary
Short summary
To understand the natural characteristics and future changes of the global extreme daily precipitation, it is necessary to explore the long-term characteristics of extreme daily precipitation. Here, we used climate simulations to analyze the characteristics and long-term changes of extreme precipitation during the past 3351 years. Our findings indicate that extreme precipitation in the past is associated with internal climate variability and regional surface temperatures.
Nedjeljka Žagar and Thomas Schäfer
Adv. Geosci., 53, 65–72, https://doi.org/10.5194/adgeo-53-65-2020, https://doi.org/10.5194/adgeo-53-65-2020, 2020
Short summary
Short summary
The paper reflects on the results of a survey carried out within the COST TN1301 Sci-Generation network among the holders of ERC starting grants originating from countries of Central and Eastern Europe. It is discussed how the the statistics of ERC starting grants is a mirror of host countries' and host institutions' ability to attract and keep the most talented young researchers.
Valerio Lembo, Frank Lunkeit, and Valerio Lucarini
Geosci. Model Dev., 12, 3805–3834, https://doi.org/10.5194/gmd-12-3805-2019, https://doi.org/10.5194/gmd-12-3805-2019, 2019
Short summary
Short summary
The Thermodynamic Diagnostic Tool (TheDiaTo v1.0) is a collection of diagnostics for the study of the thermodynamics of the climate system in climate models. This is fundamental in order to understand where the imbalances affecting climate projections come from and also to allow for easy comparison of different scenarios and atmospheric regimes. The tool is currently being developed for the assessment of models that are part of the next phase of the Coupled Model Intercomparison Project (CMIP).
Christoph C. Raible, Martina Messmer, Flavio Lehner, Thomas F. Stocker, and Richard Blender
Clim. Past, 14, 1499–1514, https://doi.org/10.5194/cp-14-1499-2018, https://doi.org/10.5194/cp-14-1499-2018, 2018
Short summary
Short summary
Extratropical cyclones in winter and their characteristics are investigated in depth for the Atlantic European region from 850 to 2100 CE. During the Common Era, cyclone characteristics show pronounced variations mainly caused by internal variability of the coupled climate system. When anthropogenic forcing becomes dominant, a strong increase of extreme cyclone-related precipitation is found due to thermodynamics, though dynamical processes can play an important role during the last millennium.
Andreas Dörnbrack, Sonja Gisinger, Natalie Kaifler, Tanja Christina Portele, Martina Bramberger, Markus Rapp, Michael Gerding, Jens Faber, Nedjeljka Žagar, and Damjan Jelić
Atmos. Chem. Phys., 18, 12915–12931, https://doi.org/10.5194/acp-18-12915-2018, https://doi.org/10.5194/acp-18-12915-2018, 2018
Short summary
Short summary
A deep upper-air sounding stimulated the current investigation of internal gravity waves excited during a minor sudden stratospheric warming (SSW) in the Arctic winter 2015/16. The analysis of the radiosonde profile revealed large kinetic and potential energies in the upper stratosphere without any simultaneous enhancement of upper tropospheric and lower stratospheric values. In combination with high-resolution meteorological analyses we identified an elevated source of gravity wave excitation.
Marten Blaauw and Nedjeljka Žagar
Atmos. Chem. Phys., 18, 8313–8330, https://doi.org/10.5194/acp-18-8313-2018, https://doi.org/10.5194/acp-18-8313-2018, 2018
Short summary
Short summary
The equatorial Kelvin wave (KW) is the most studied wave feature of the tropical atmosphere, yet not well quantified. Our study simultaneously analyses wind and temperature fields of KWs from ECMWF analyses without any prior data filtering. We provide the KW energy spectrum and its seasonal variability for three KW frequency ranges. We developed a webpage to show the spatial structure of KWs propagating in time through the ECMWF data, http://modes.fmf.uni-lj.si, updated on a daily basis.
Tamás Bódai, Valerio Lucarini, and Frank Lunkeit
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2018-30, https://doi.org/10.5194/esd-2018-30, 2018
Revised manuscript not accepted
Short summary
Short summary
We establish a framework to conduct a scenario analysis of the best possible outcomes under geoengineering. The scenarios may consist of scenarios of greenhouse gas emission the choice of the quantity that we want to keep under control. The motivation is the desire of an efficient way of assessing the side-effects of geoengineering, concerning the unwanted and uncontrolled changes. Countering CO2 emission by modulating insolation, we find considerable changes in local temperatures or rainfall.
Maida Zahid, Richard Blender, Valerio Lucarini, and Maria Caterina Bramati
Earth Syst. Dynam., 8, 1263–1278, https://doi.org/10.5194/esd-8-1263-2017, https://doi.org/10.5194/esd-8-1263-2017, 2017
Short summary
Short summary
The southern part of Pakistan (Sindh province) has been exposed to frequent and intense temperature extremes recently and is highly vulnerable to their impacts due to lack of information on recurrence of extremes. In this paper for the first time we estimated the return levels of daily maximum temperatures and daily maximum wet-bulb temperatures over the different return periods in Sindh, which would help the local administrations to prioritize the regions in terms of adaptations.
M.-A. Knietzsch, A. Schröder, V. Lucarini, and F. Lunkeit
Earth Syst. Dynam., 6, 591–615, https://doi.org/10.5194/esd-6-591-2015, https://doi.org/10.5194/esd-6-591-2015, 2015
Short summary
Short summary
A general circulation model with an aquaplanet setup is used to study the impact of changes in the oceanic heat transport (OHT) on the atmospheric circulation. The atmosphere counterbalances the imposed changes in OHT. A stronger OHT leads to a decline in the intensity and a poleward shift of the maxima of both the Hadley and Ferrel cells. The efficiency of the climate machine, the intensity of the Lorenz energy cycle and the material entropy production of the system decline with increased OHT.
R. Žabkar, L. Honzak, G. Skok, R. Forkel, J. Rakovec, A. Ceglar, and N. Žagar
Geosci. Model Dev., 8, 2119–2137, https://doi.org/10.5194/gmd-8-2119-2015, https://doi.org/10.5194/gmd-8-2119-2015, 2015
N. Žagar, A. Kasahara, K. Terasaki, J. Tribbia, and H. Tanaka
Geosci. Model Dev., 8, 1169–1195, https://doi.org/10.5194/gmd-8-1169-2015, https://doi.org/10.5194/gmd-8-1169-2015, 2015
Short summary
Short summary
The article presents MODES, a new software for the analysis of properties of balanced and inertio-gravity circulations across many scales in (re)analyses, weather forecasts and climate models. The software and real-time results based on ECMWF model can be found at http://meteo.fmf.uni-lj.si/MODES. Evaluation of models' ability to reproduce the unbalanced tropical circulation is expected to provide new insights on model performance that is helpful to diagnose deficiencies and define improvements.
V. Blažica, N. Gustafsson, and N. Žagar
Geosci. Model Dev., 8, 87–97, https://doi.org/10.5194/gmd-8-87-2015, https://doi.org/10.5194/gmd-8-87-2015, 2015
Short summary
Short summary
The paper deals with the comparison of the common periodization methods used to obtain spectral fields of limited-area models for numerical weather prediction. The focus is on the impact the methods have on the spectra of the fields. The results show that detrending and DCT have little impact on the spectra, as does the Boyd method for extension zone. For the ALADIN and HIRLAM methods, the impact depends on the width of the extension zone - the wider the zone, the larger impact on the spectra.
C. Cardinali, N. Žagar, G. Radnoti, and R. Buizza
Nonlin. Processes Geophys., 21, 971–985, https://doi.org/10.5194/npg-21-971-2014, https://doi.org/10.5194/npg-21-971-2014, 2014
P. B. Holden, N. R. Edwards, P. H. Garthwaite, K. Fraedrich, F. Lunkeit, E. Kirk, M. Labriet, A. Kanudia, and F. Babonneau
Geosci. Model Dev., 7, 433–451, https://doi.org/10.5194/gmd-7-433-2014, https://doi.org/10.5194/gmd-7-433-2014, 2014
Related subject area
Dynamical processes in midlatitudes
Minimal influence of future Arctic sea ice loss on North Atlantic jet stream morphology
Weather type reconstruction using machine learning approaches
Temporally and zonally varying atmospheric waveguides – climatologies and connections to quasi-stationary waves
Moisture transport axes: a unifying definition for tropical moisture exports, atmospheric rivers, and warm moist intrusions
On the movement of atmospheric blocking systems and the associated temperature responses
An ERA5 climatology of synoptic-scale negative potential vorticity–jet interactions over the western North Atlantic
Quantifying the spread in sudden stratospheric warming wave forcing in CMIP6
Synoptic perspective on the conversion and maintenance of local available potential energy in extratropical cyclones
Frequency anomalies and characteristics of extratropical cyclones during extremely wet, dry, windy, and calm seasons in the extratropics
Two different perspectives on heatwaves within the Lagrangian framework
From sea to sky: understanding the sea surface temperature impact on an atmospheric blocking event using sensitivity experiments with the ICOsahedral Nonhydrostatic (ICON) model
Simulating record-shattering cold winters of the beginning of the 21st century in France
Detection and consequences of atmospheric deserts: insights from a case study
A global climatology of sting-jet extratropical cyclones
The impact of preceding convection on the development of Medicane Ianos and the sensitivity to sea surface temperature
The importance of diabatic processes for the dynamics of synoptic-scale extratropical weather systems – a review
The impact of synoptic storm likelihood on European subseasonal forecast uncertainty and their modulation by the stratosphere
Spatio-temporal averaging of jets obscures the reinforcement of baroclinicity by latent heating
Trends and seasonal signals in Atlantic feature-based jet stream characteristics and in weather types
Impact of stochastic physics on the representation of atmospheric blocking in EC-Earth3
Long vs. Short: Understanding the dynamics of persistent summer hot spells in Europe
The crucial representation of deep convection for the cyclogenesis of Medicane Ianos
Environments and lifting mechanisms of cold-frontal convective cells during the warm-season in Germany
Extreme weather anomalies and surface signatures associated with merged Atlantic-African jets during winter
The connection between North Atlantic storm track regimes and eastern Mediterranean cyclonic activity
A storm-relative climatology of compound hazards in Mediterranean cyclones
A new characterisation of the North Atlantic eddy-driven jet using two-dimensional moment analysis
Linking compound weather extremes to Mediterranean cyclones, fronts, and airstreams
A linear assessment of barotropic Rossby wave propagation in different background flow configurations
Towards a process-oriented understanding of the impact of stochastic perturbations on the model climate
Deepening mechanisms of cut-off lows in the Southern Hemisphere and the role of jet streams: insights from eddy kinetic energy analysis
Large-scale perspective on extreme near-surface winds in the central North Atlantic
Divergent convective outflow in ICON deep-convection-permitting and parameterised deep convection simulations
Changes in the North Atlantic Oscillation over the 20th century
Life cycle dynamics of Greenland blocking from a potential vorticity perspective
Warm conveyor belt characteristics and impacts along the life cycle of extratropical cyclones: case studies and climatological analysis based on ERA5
Influence of radiosonde observations on the sharpness and altitude of the midlatitude tropopause in the ECMWF IFS
Analysing 23 years of warm-season derechos in France: a climatology and investigation of synoptic and environmental changes
A Lagrangian framework for detecting and characterizing the descent of foehn from Alpine to local scales
The upstream–downstream connection of North Atlantic and Mediterranean cyclones in semi-idealized simulations
Understanding the vertical temperature structure of recent record-shattering heatwaves
Persistent warm and cold spells in the Northern Hemisphere extratropics: regionalisation, synoptic-scale dynamics and temperature budget
Linking Gulf Stream air–sea interactions to the exceptional blocking episode in February 2019: a Lagrangian perspective
Process-based classification of Mediterranean cyclones using potential vorticity
The relation between Rossby wave-breaking events and low-level weather systems
Aquaplanet simulations with winter and summer hemispheres: model setup and circulation response to warming
Seasonally dependent increases in subweekly temperature variability over Southern Hemisphere landmasses detected in multiple reanalyses
Identification of high-wind features within extratropical cyclones using a probabilistic random forest – Part 2: Climatology over Europe
Cold wintertime air masses over Europe: where do they come from and how do they form?
Diabatic effects on the evolution of storm tracks
Yvonne Anderson, Jacob Perez, and Amanda C. Maycock
Weather Clim. Dynam., 6, 595–608, https://doi.org/10.5194/wcd-6-595-2025, https://doi.org/10.5194/wcd-6-595-2025, 2025
Short summary
Short summary
The impact of Arctic sea ice loss on the North Atlantic jet stream is debated, with some linking changes to ice loss and others to natural variability. This study uses a new method to explore how future sea ice loss will affect the jet stream. In half of the models, the jet shifts equatorward, but its speed and tilt are unchanged. Some models also exhibit more jet splitting. The results suggest that future sea ice loss is unlikely to significantly weaken the jet stream or make it more variable.
Lucas Pfister, Lena Wilhelm, Yuri Brugnara, Noemi Imfeld, and Stefan Brönnimann
Weather Clim. Dynam., 6, 571–594, https://doi.org/10.5194/wcd-6-571-2025, https://doi.org/10.5194/wcd-6-571-2025, 2025
Short summary
Short summary
Our work compares different machine learning approaches for creating long-term classifications of daily atmospheric circulation patterns using input data from surface meteorological observations. Our comparison reveals that a feedforward neural network performs best at this task. Using this model, we present a daily reconstruction of a commonly used weather type classification for central Europe that dates back to 1728.
Rachel H. White and Lualawi Mareshet Admasu
Weather Clim. Dynam., 6, 549–570, https://doi.org/10.5194/wcd-6-549-2025, https://doi.org/10.5194/wcd-6-549-2025, 2025
Short summary
Short summary
Mid-latitude atmospheric jet streams sometimes create "waveguides", which are thought to increase the chance of quasi-stationary waves – atmospheric circulation patterns that can lead to extreme weather events. We compare two methods of identifying atmospheric waveguides, finding that one method seems to be less impacted by the presence of waves and provides much stronger correlations with enhanced quasi-stationary waves, and recommend this method for future studies.
Clemens Spensberger, Kjersti Konstali, and Thomas Spengler
Weather Clim. Dynam., 6, 431–446, https://doi.org/10.5194/wcd-6-431-2025, https://doi.org/10.5194/wcd-6-431-2025, 2025
Short summary
Short summary
The transport of moisture from warmer and moister to colder and drier regions mainly occurs in brief and narrow bursts. In the mid-latitudes, such bursts are generally referred to as atmospheric rivers; in the Arctic they are often referred to as warm moist intrusions. We introduce a new definition to identify such bursts which is based primarily on their elongated structure. With this more general definition, we show that bursts in moisture transport occur frequently across all climate zones.
Jonna van Mourik, Hylke de Vries, and Michiel Baatsen
Weather Clim. Dynam., 6, 413–429, https://doi.org/10.5194/wcd-6-413-2025, https://doi.org/10.5194/wcd-6-413-2025, 2025
Short summary
Short summary
Atmospheric blocking events are quasi-stationary high-pressure areas with large influences on our weather. In this study, we show the wide variety of zonal velocities possible for atmospheric blocking under the most used blocking indices. These include not only stationary blocks, but also eastward- and westward-moving blocks. These respective moving blocks are found to have different characteristics in size and location and have different impacts on our surface temperatures.
Alexander Lojko, Andrew C. Winters, Annika Oertel, Christiane Jablonowski, and Ashley E. Payne
Weather Clim. Dynam., 6, 387–411, https://doi.org/10.5194/wcd-6-387-2025, https://doi.org/10.5194/wcd-6-387-2025, 2025
Short summary
Short summary
Convective storms can produce intense anticyclonically rotating vortices (~10 km) defined by negative potential vorticity (NPV), which can elongate to larger scales (~1000 km). Our composite analysis shows that elongated NPV frequently occurs along the western North Atlantic tropopause, where we observed it enhancing jet stream kinematics. Elongated NPV may impinge on aviation turbulence and weather forecasting despite its small-scale origin.
Verónica Martínez-Andradas, Alvaro de la Cámara, Pablo Zurita-Gotor, François Lott, and Federico Serva
Weather Clim. Dynam., 6, 329–343, https://doi.org/10.5194/wcd-6-329-2025, https://doi.org/10.5194/wcd-6-329-2025, 2025
Short summary
Short summary
Global circulation model biases are present when simulating sudden stratospheric warmings (SSWs). These are important extreme phenomena that occur in the wintertime stratosphere, driven by the breaking of atmospheric waves. The present work shows that there is a large spread of the wave forcing during the development of SSWs in different models. In the mesosphere, gravity waves are found to force advection of the residual circulation, while planetary waves tend to decelerate the wind.
Marc Federer, Lukas Papritz, Michael Sprenger, and Christian M. Grams
Weather Clim. Dynam., 6, 211–230, https://doi.org/10.5194/wcd-6-211-2025, https://doi.org/10.5194/wcd-6-211-2025, 2025
Short summary
Short summary
Although extratropical cyclones in the North Atlantic are among the most impactful midlatitude weather systems, their intensification is not entirely understood. Here, we explore how individual cyclones convert available potential energy (APE) into kinetic energy and relate these conversions to the synoptic development of the cyclones. By combining potential vorticity thinking with a local APE framework, we offer a novel perspective on established concepts in dynamic meteorology.
Hanin Binder and Heini Wernli
Weather Clim. Dynam., 6, 151–170, https://doi.org/10.5194/wcd-6-151-2025, https://doi.org/10.5194/wcd-6-151-2025, 2025
Short summary
Short summary
This study presents a systematic analysis of frequency anomalies and characteristics of extratropical cyclones during extremely wet, dry, windy, and calm winter and summer seasons in the extratropics based on 1050 years of present-day climate simulations. We show that anomalies in cyclone frequency, intensity, and stationarity are crucial to the occurrence of many extreme seasons and that these anomaly patterns exhibit substantial regional and seasonal variability.
Amelie Mayer and Volkmar Wirth
Weather Clim. Dynam., 6, 131–150, https://doi.org/10.5194/wcd-6-131-2025, https://doi.org/10.5194/wcd-6-131-2025, 2025
Short summary
Short summary
Although heatwaves are among the most dangerous weather-related hazards, their underlying mechanisms are not fully understood. Here, we investigate the formation of heatwaves in an air-parcel-based framework and distinguish the contributions from horizontal transport, vertical transport, and diabatic heating. We show that the results obtained depend profoundly on whether one compares the absolute contributions of the individual terms or, instead, their anomalies relative to climatology.
Svenja Christ, Marta Wenta, Christian M. Grams, and Annika Oertel
Weather Clim. Dynam., 6, 17–42, https://doi.org/10.5194/wcd-6-17-2025, https://doi.org/10.5194/wcd-6-17-2025, 2025
Short summary
Short summary
The detailed representation of sea surface temperature (SST) in numerical models is important for the prediction of atmospheric blocking in the North Atlantic. Yet the underlying physical processes are not fully understood. Using SST sensitivity experiments for a case study, we identify a physical pathway through which SST in the Gulf Stream region is linked to the downstream upper-level flow evolution in the North Atlantic.
Camille Cadiou and Pascal Yiou
Weather Clim. Dynam., 6, 1–15, https://doi.org/10.5194/wcd-6-1-2025, https://doi.org/10.5194/wcd-6-1-2025, 2025
Short summary
Short summary
Extreme cold winter temperatures in Europe have huge societal impacts. This study focuses on extreme cold events, such as the winter of 1963 in France, which are expected to become rarer due to climate change. We use a light and efficient rare-event algorithm to simulate a large number of extreme cold winters over France to analyse their characteristics. We find that despite fewer occurrences, their intensity remains steady. We analyse prevailing atmospheric circulation during these events.
Fiona Fix, Georg Mayr, Achim Zeileis, Isabell Stucke, and Reto Stauffer
Weather Clim. Dynam., 5, 1545–1560, https://doi.org/10.5194/wcd-5-1545-2024, https://doi.org/10.5194/wcd-5-1545-2024, 2024
Short summary
Short summary
Atmospheric deserts (ADs) are air masses that are transported away from hot, dry regions. Our study introduces this new concept. ADs can suppress or boost thunderstorms and potentially contribute to the formation of heat waves, which makes them relevant for forecasting extreme events. Using a novel detection method, we follow an AD directly from North Africa to Europe for a case in June 2022, allowing us to analyse the air mass at any time and investigate how it is modified along the way.
Suzanne L. Gray, Ambrogio Volonté, Oscar Martínez-Alvarado, and Ben J. Harvey
Weather Clim. Dynam., 5, 1523–1544, https://doi.org/10.5194/wcd-5-1523-2024, https://doi.org/10.5194/wcd-5-1523-2024, 2024
Short summary
Short summary
Sting jets occur in some of the most damaging cyclones impacting Europe. We present the first climatology of sting-jet cyclones over the major ocean basins. Cyclones with sting-jet precursors occur over the North Atlantic, North Pacific, and Southern Oceans, with implications for wind warnings. Precursor cyclones have distinct characteristics, even in reanalyses that are too coarse to fully resolve sting jets, evidencing the climatological consequences of strong diabatic cloud processes.
Claudio Sánchez, Suzanne Gray, Ambrogio Volonté, Florian Pantillon, Ségolène Berthou, and Silvio Davolio
Weather Clim. Dynam., 5, 1429–1455, https://doi.org/10.5194/wcd-5-1429-2024, https://doi.org/10.5194/wcd-5-1429-2024, 2024
Short summary
Short summary
Medicane Ianos was a very intense cyclone that led to harmful impacts over Greece. We explore what processes are important for the forecasting of Medicane Ianos, with the use of the Met Office weather model. There was a preceding precipitation event before Ianos’s birth, whose energetics generated a bubble in the tropopause. This bubble created the necessary conditions for Ianos to emerge and strengthen, and the processes are enhanced in simulations with a warmer Mediterranean Sea.
Heini Wernli and Suzanne L. Gray
Weather Clim. Dynam., 5, 1299–1408, https://doi.org/10.5194/wcd-5-1299-2024, https://doi.org/10.5194/wcd-5-1299-2024, 2024
Short summary
Short summary
The science of extratropical dynamics has reached a new level where the interplay of dry dynamics with effects of latent heating in clouds and other diabatic processes is considered central to the field. This review documents how research about the role of diabatic processes evolved over more than a century; it highlights that progress relied essentially on the integration of theory, field campaigns, novel diagnostics, and numerical modelling, and it outlines avenues for future research.
Philip Rupp, Jonas Spaeth, Hilla Afargan-Gerstman, Dominik Büeler, Michael Sprenger, and Thomas Birner
Weather Clim. Dynam., 5, 1287–1298, https://doi.org/10.5194/wcd-5-1287-2024, https://doi.org/10.5194/wcd-5-1287-2024, 2024
Short summary
Short summary
We quantify the occurrence of strong synoptic storms as contributing about 20 % to the uncertainty of subseasonal geopotential height forecasts over northern Europe. We further show that North Atlantic storms are less frequent, weaker and shifted southward following sudden stratospheric warming events, leading to a reduction in northern European forecast uncertainty.
Henrik Auestad, Clemens Spensberger, Andrea Marcheggiani, Paulo Ceppi, Thomas Spengler, and Tim Woollings
Weather Clim. Dynam., 5, 1269–1286, https://doi.org/10.5194/wcd-5-1269-2024, https://doi.org/10.5194/wcd-5-1269-2024, 2024
Short summary
Short summary
Latent heating due to condensation can influence atmospheric circulation by strengthening or weakening horizontal temperature contrasts. Strong temperature contrasts intensify storms and imply the existence of strong upper tropospheric winds called jets. It remains unclear whether latent heating preferentially reinforces or abates the existing jet. We show that this disagreement is attributable to how the jet is defined, confirming that latent heating reinforces the jet.
Hugo Banderier, Alexandre Tuel, Tim Woollings, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2024-3029, https://doi.org/10.5194/egusphere-2024-3029, 2024
Short summary
Short summary
The jet stream is the main feature of the upper level flow, and drives the weather at the surface. It is stronger and better defined in winter, and has mostly been studied in that season. However, it is very important for (extreme) weather in summer. In this work, we improve and use two existing and complementary methods to study the jet stream(s) in the Euro-Atlantic sector, with a focus on summer. We find that our methods can verify each other and agree on interesting signals and trends.
Michele Filippucci, Simona Bordoni, and Paolo Davini
Weather Clim. Dynam., 5, 1207–1222, https://doi.org/10.5194/wcd-5-1207-2024, https://doi.org/10.5194/wcd-5-1207-2024, 2024
Short summary
Short summary
Atmospheric blocking is a recurring phenomenon in midlatitudes, causing winter cold spells and summer heat waves. Current models underestimate it, hindering understanding of global warming's impact on extremes. In this paper, we investigate whether stochastic parameterizations can improve blocking representation. We find that blocking frequency representation slightly deteriorates, following a change in midlatitude winds. We conclude by suggesting a direction for future model development.
Duncan Pappert, Alexandre Tuel, Dim Coumou, Mathieu Vrac, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2024-2980, https://doi.org/10.5194/egusphere-2024-2980, 2024
Short summary
Short summary
This study examines the mechanisms that characterise long-lasting (persistent) and short hot spells in Europe in a comparative framework. By analysing weather data, we found that long spells in Southwestern Europe are typically preceded by dry soil conditions and driven by multiple persistence-inducing mechanisms. In contrast, short spells occur in a more transient atmospheric situation and exhibit fewer drivers. Understanding persistent heat extremes can help improve their prediction.
Florian Pantillon, Silvio Davolio, Elenio Avolio, Carlos Calvo-Sancho, Diego Saul Carrió, Stavros Dafis, Emanuele Silvio Gentile, Juan Jesus Gonzalez-Aleman, Suzanne Gray, Mario Marcello Miglietta, Platon Patlakas, Ioannis Pytharoulis, Didier Ricard, Antonio Ricchi, Claudio Sanchez, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 1187–1205, https://doi.org/10.5194/wcd-5-1187-2024, https://doi.org/10.5194/wcd-5-1187-2024, 2024
Short summary
Short summary
Cyclone Ianos of September 2020 was a high-impact but poorly predicted medicane (Mediterranean hurricane). A community effort of numerical modelling provides robust results to improve prediction. It is found that the representation of local thunderstorms controlled the interaction of Ianos with a jet stream at larger scales and its subsequent evolution. The results help us understand the peculiar dynamics of medicanes and provide guidance for the next generation of weather and climate models.
George Pacey, Stephan Pfahl, and Lisa Schielicke
EGUsphere, https://doi.org/10.5194/egusphere-2024-2978, https://doi.org/10.5194/egusphere-2024-2978, 2024
Short summary
Short summary
Cold fronts are often associated with areas of intense precipitation (cells) in the warm-season, but the drivers and environments of cells at different locations relative to the front are not well-understood. We show that cells ahead of the surface front have the highest amount of environmental instability and moisture. Also, low-level lifting is maximised ahead of the surface front and upper-level lifting is particularly important for cell initiation behind the front.
Sohan Suresan, Nili Harnik, and Rodrigo Caballero
EGUsphere, https://doi.org/10.5194/egusphere-2024-2745, https://doi.org/10.5194/egusphere-2024-2745, 2024
Short summary
Short summary
This study explores how extreme winter weather events across the Northern Hemisphere are influenced by the rare merging of the Atlantic and African jets, beyond the typical factors like NAO and ENSO. We identify unique surface signals and changes in cyclone paths associated with such persistent jet merging over the Atlantic, offering insights into these extreme winter weather patterns.
Dor Sandler, Hadas Saaroni, Baruch Ziv, Talia Tamarin-Brodsky, and Nili Harnik
Weather Clim. Dynam., 5, 1103–1116, https://doi.org/10.5194/wcd-5-1103-2024, https://doi.org/10.5194/wcd-5-1103-2024, 2024
Short summary
Short summary
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.
Raphaël Rousseau-Rizzi, Shira Raveh-Rubin, Jennifer L. Catto, Alice Portal, Yonatan Givon, and Olivia Martius
Weather Clim. Dynam., 5, 1079–1101, https://doi.org/10.5194/wcd-5-1079-2024, https://doi.org/10.5194/wcd-5-1079-2024, 2024
Short summary
Short summary
We identify situations when rain and wind, rain and wave, or heat and dust hazards co-occur within Mediterranean cyclones. These hazard combinations are associated with risk to infrastructure, risk of coastal flooding and risk of respiratory issues. The presence of Mediterranean cyclones is associated with increased probability of all three hazard combinations. We identify weather configurations and cyclone structures, particularly those associated with specific co-occurrence combinations.
Jacob Perez, Amanda C. Maycock, Stephen D. Griffiths, Steven C. Hardiman, and Christine M. McKenna
Weather Clim. Dynam., 5, 1061–1078, https://doi.org/10.5194/wcd-5-1061-2024, https://doi.org/10.5194/wcd-5-1061-2024, 2024
Short summary
Short summary
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 characterisation. 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.
Alice Portal, Shira Raveh-Rubin, Jennifer L. Catto, Yonatan Givon, and Olivia Martius
Weather Clim. Dynam., 5, 1043–1060, https://doi.org/10.5194/wcd-5-1043-2024, https://doi.org/10.5194/wcd-5-1043-2024, 2024
Short summary
Short summary
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 especially 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 vary by region and season, depending on the presence of specific airflows around the cyclone.
Antonio Segalini, Jacopo Riboldi, Volkmar Wirth, and Gabriele Messori
Weather Clim. Dynam., 5, 997–1012, https://doi.org/10.5194/wcd-5-997-2024, https://doi.org/10.5194/wcd-5-997-2024, 2024
Short summary
Short summary
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
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Barriopedro, D., Fischer, E. M., Luterbacher, J., Trigo, R. M., and García-Herrera, R.: The Hot Summer of 2010: Redrawing the Temperature Record Map of Europe, Science, 332, 220–224, https://doi.org/10.1126/science.1201224, 2011. a, b
Behera, S. K., Ratnam, J. V., Masumoto, Y., and Yamagata, T.: Origin of extreme summers in Europe: the Indo-Pacific connection, Clim. Dynam., 41, 663–676, https://doi.org/10.1007/s00382-012-1524-8, 2012. a, b
Coumou, D., Petoukhov, V., Rahmstorf, S., Petri, S., and Schellnhuber, H. J.: Quasi-resonant circulation regimes and hemispheric synchronization of extreme weather in boreal summer, P. Natl. Acad. Sci. USA, 111, 12331–12336, https://doi.org/10.1073/pnas.1412797111, 2014. a, b, c
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S. B., Hersbach, H., Hólm, E. V., Isaksen, L., Kållberg, P., Köhler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M., Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thépaut, J.-N., and Vitart, F.: The ERA-Interim reanalysis: configuration and performance of the data assimilation system, Q. J. Roy. Meteor. Soc., 137, 553–597, https://doi.org/10.1002/qj.828, 2011 (data available at: https://apps.ecmwf.int/datasets/data/interim-full-daily/levtype=ml/, last access: 18 November 2022). a
Drouard, M. and Woollings, T.: Contrasting mechanisms of summer blocking over western Eurasia, Geophys. Res. Lett., 45, 12040–12048,
https://doi.org/10.1029/2018GL079894, 2018. a
Emerton, R., Brimicombe, C., Magnusson, L., Roberts, C., Di Napoli, C., Cloke, H. L., and Pappenberger, F.: Predicting the unprecedented: forecasting the June 2021 Pacific Northwest heatwave, Weather, 77, 272–279, https://doi.org/10.1002/wea.4257, 2022. a
Feudale, L. and Shukla, J.: Influence of sea surface temperature on the European heat wave of 2003 summer. Part I: an observational study, Clim. Dynam., 36, 1691–1703, https://doi.org/10.1007/s00382-010-0788-0, 2011. a
Fuentes-Franco, R., Koenigk, T., Docquier, D., Graef, F., and Wyser, K.: Exploring the influence of the North Pacific Rossby wave sources on the variability of summer atmospheric circulation and precipitation over the Northern Hemisphere, Clim. Dynam., 59, 2025–2039, https://doi.org/10.1007/s00382-022-06194-4, 2022. a
Galfi, V. M. and Lucarini, V.: Fingerprinting Heatwaves and Cold Spells and Assessing Their Response to Climate Change Using Large Deviation Theory, Phys. Rev. Lett., 127, 058701, https://doi.org/10.1103/PhysRevLett.127.058701, 2021. a
Hersbach, H., Bell, B., Berrisford, P., et al.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020 (data available at: https://cds.climate.copernicus.eu/cdsapp#!/search?text=ERA5, last access: 18 November 2022). a
Kasahara, A.: 3D Normal Mode Functions (NMFs) of a Global Baroclinic Atmospheric Model, in: Modal View of Atmospheric Variability. Mathematics of Planet Earth, Vol. 8, edited by: Žagar, N. and Tribbia, J., Springer, Cham, https://doi.org/10.1007/978-3-030-60963-4_1, 2020. a, b, c, d
Kasahara, A. and Puri, K.: Spectral representation of three-dimensional global data by expansion in normal mode functions, Mon. Weather Rev., 109, 37–51, 1981. a
Kautz, L.-A., Martius, O., Pfahl, S., Pinto, J. G., Ramos, A. M., Sousa, P. M., and Woollings, T.: Atmospheric blocking and weather extremes over the Euro-Atlantic sector – a review, Weather Clim. Dynam., 3, 305–336, https://doi.org/10.5194/wcd-3-305-2022, 2022. 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, https://doi.org/10.2151/jmsj.2015-001, 2015 (data available at: https://search.diasjp.net/en/dataset/JRA55, last access: 18 November 2022). a
Kornhuber, K., Osprey, S., Coumou, D., Petri, S., Vladimir, P., and Rahmstorf, S., and, Gray, L.: Extreme weather events in early summer 2018 connected by a recurrent hemispheric wave-7 pattern, Environ. Res. Lett., 14, 054002, https://doi.org/10.1088/1748-9326/ab13bf, 2019. a, b
Kornhuber, K., Coumou, D., Vogel, E., Lesk, C., Donges, J. F., Lehmann, J., and Horton, R. M.: Amplified Rossby waves enhance risk of concurrent heatwaves in major breadbasket regions, Nat. Clim. Change, 10, 48–53, https://doi.org/10.1038/s41558-019-0637-z, 2020. a
Lau, W. K. M. and Kim, K.-M.: The 2010 Pakistan flood and Russian heat wave: Teleconnection of hydrometeorological extremes, J. Hydrometeorol., 13, 392–403, https://doi.org/10.1175/JHM-D-11-016.1, 2012. a, b
Lucarini, V. and Gritsun, A.: A new mathematical framework for atmospheric blocking events, Clim. Dynam., 54, 575–598, https://doi.org/10.1007/s00382-019-05018-2, 2020. a, b
Ma, Q. and Franzke, C. L. E.: The role of transient eddies and diabatic heating in the maintenance of European heat waves: a nonlinear quasi-stationary wave perspective, Clim. Dynam., 56, 2983–3002, https://doi.org/10.1007/s00382-021-05628-9, 2021. a
Nakamura, N. and Huang, C. S.: Atmospheric blocking as a traffic jam in the jet stream, Science, 361, 42–47, https://doi.org/10.1126/science.aat0721, 2018. a
Park, M. and Lee, S.: Relationship between tropical and extratropical diabatic heating and their impact on stationary–transient wave interference, J. Atmos. Sci., 76, 2617–2633, https://doi.org/10.1175/JAS-D-18-0371.1, 2019. a
Perron, M. and Sura, P.: Climatology of non-Gaussian atmospheric statistics, J. Climate., 26, 1063–1083, https://doi.org/10.1175/JCLI-D-11-00504.1, 2013. a
Petoukhov, V., Rahmstorf, S., Petri, S., and Schellnhuber, H. J.: Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes, P. Natl. Acad. Sci. USA, 110, 5336–5341, https://doi.org/10.1073/pnas.1222000110, 2013. a, b
Ragone, F. and Bouchet, F.: Rare Event Algorithm Study of Extreme Warm Summers and Heatwaves Over Europe, Geophys. Res. Lett., 48, e2020GL091197, https://doi.org/10.1029/2020gl091197, 2021. a
Rienecker, M. M., Suarez, M. J., Gelaro, R., Todling, R., Bacmeister, J., Liu, E., Bosilovich, M. G., Schubert, S. D., Takacs, L., Kim, G.-K., Bloom, S., Chen, J., Collins, D., Conaty, A., da Silva, A., Gu, W., Joiner, J., Koster, R. D., Lucchesi, R., Molod, A., Owens, T., Pawson, S., Pegion, P., Redder, C. R., Reichle, R., Robertson, F. R., Ruddick, A. G., Sienkiewicz, M., and Woollen, J.: MERRA: NASA’s Modern-Era Retrospective Analysis for Research and Applications, J. Climate, 24, 3624–3648, https://doi.org/10.1175/JCLI-D-11-00015.1, 2011 (data available at: https://disc.gsfc.nasa.gov/datasets?project=MERRA, last access: 18 November 2022). a
Rousi, E., Kornhuber, K., Beobide-Arsuaga, G., Luo, F., and Coumou, D.: Accelerated western European heatwave trends linked to more-persistent double jets over Eurasia, Nat. Commun., 13, 3851, https://doi.org/10.1038/s41467-022-31432-y, 2022. a, b, c
Schneidereit, A., Schubert, S., Vargin, P., Lunkeit, F., Zhu, X., Peters, D. H., and Fraedrich, K.: Large-scale flow and the long-lasting blocking high over Russia: Summer 2010, Mon Weather Rev., 140, 2967–2981, https://doi.org/10.1175/MWR-D-11-00249.1, 2012. a
Screen, J. A. and Simmonds, I.: Amplified mid-latitude planetary waves favour particular regional weather extremes, Nat. Clim. Change, 4, 704–709, https://doi.org/10.1038/nclimate2271, 2014. a
Shutts, G.: The propagation of eddies in diffluent jetstreams: Eddy vorticity forcing of 'blocking' flow fields, Q. J. Roy. Meteor. Soc., 109, 737–761, https://doi.org/10.1002/qj.49710946204, 1983. a, b
Stefanon, M., D'Andrea, F., and Drobinski, P.: Heatwave classification over Europe and the Mediterranean region, Environ. Res. Lett., 7, 014023, https://doi.org/10.1088/1748-9326/7/1/014023, 2012. a
Sura, P., Newman, M., Penland, C., and Sardeshmukh, P.: Multiplicative noise and non-Gaussianity: A paradigm for atmospheric regimes?, J. Atmos. Sci., 62, 1391–1409, https://doi.org/10.1175/JAS3408.1, 2005. a
Teng, H. and Branstator, G.: A zonal wavenumber 3 pattern of Northern Hemisphere wintertime planetary wave variability at high latitudes, J. Climate, 25, 6756–6769, https://doi.org/10.1175/JCLI-D-11-00664.1, 2012. a
Teng, H. and Branstator, G.: Amplification of Waveguide Teleconnections in the Boreal Summer, Current Climate Change Reports, 5, 421–432, https://doi.org/10.1007/s40641-019-00150-x, 2019. a, b, c
Trenberth, K. E. and Fasullo, J. T.: Climate extremes and climate change: The Russian heat wave and other climate extremes of 2010, J. Geophys. Res., 117, D17103, https://doi.org/10.1029/2012JD018020, 2012. a
Wiedenmann, J. M., Lupo, A. R., Mokhov, I. I., and Tikhonova, E. A.: The climatology of blocking anticyclones for the Northern and Southern Hemispheres: Block intensity as a diagnostic, J. Climate, 15, 3459–3473, https://doi.org/10.1175/1520-0442(2002)015<3459:TCOBAF>2.0.CO;2, 2002. a
Wilks, D. S.: Statistical methods in the atmospheric sciences, Vol. 100 of
International Geophysics, 3rd edn., Academic Press, http://www.sciencedirect.com/science/bookseries/00746142/100/supp/C (last access: 18 November 2022), 2011. a
Wirth, V. and Polster, C.: The problem of diagnosing jet waveguidability in the presence of large-amplitude eddies, J. Atmos. Sci., 78, 3137–3151, https://doi.org/10.1175/JAS-D-20-0292.1, 2021. a, b
Woollings, T., Barriopedro, D., Methven, J., Son, S.-W., Martius, O., Harvey, B., Sillmann, J., Lupo, A. R., and Seneviratne, S.: Blocking and its response to climate change, Current Climate Change Reports, 4, 287–300, https://doi.org/10.1007/s40641-018-0108-z, 2018. a
Xu, P., Wang, L., Liu, Y., Chen, W., and Huang, P.: The record-breaking heat wave of June 2019 in Central Europe, Atmos. Sci. Lett., 21, e964, https://doi.org/10.1002/asl.964, 2020. a
Yamazaki, A. and Itoh, H.: Vortex–vortex interactions for the maintenance of blocking. Part I: The selective absorption mechanism and a case study, J. Atmos. Sci., 70, 725–742, https://doi.org/10.1175/JAS-D-11-0295.1, 2013. a, b
Žagar, N., Kasahara, A., Terasaki, K., Tribbia, J., and Tanaka, H.: Normal-mode function representation of global 3-D data sets: open-access software for the atmospheric research community, Geosci. Model Dev., 8, 1169–1195, https://doi.org/10.5194/gmd-8-1169-2015, 2015 (data available at:
https://modes.cen.uni-hamburg.de, last access: 18 November 2022). a, b, c
Žagar, N., Jelić, D., Blaauw, M., and Bechtold, P.: Energy spectra and inertia–gravity waves in global analyses, J. Atmos. Sci., 74, 2447–2466, https://doi.org/10.1175/JAS-D-16-0341.1, 2017.
a, b
Žagar, N., Kosovelj, K., Manzini, E., Horvat, M., and Castanheira, J.: An assessment of scale-dependent variability and bias in global prediction models, Clim. Dynam., 54, 287–306, https://doi.org/10.1007/s00382-019-05001-x, 2019. a
Zhou, Y. and Wu, Z.: Possible impacts of mega-El Ni no/Southern Oscillation and Atlantic Multidecadal Oscillation on Eurasian heatwave frequency variability, Q. J. Roy. Meteor. Soc., 142, 1647–1661, https://doi.org/10.1002/qj.2759, 2016. a
Short summary
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.
We show that the Eurasian heat waves (HWs) have signatures in the global circulation. We present...
