Articles | Volume 3, issue 3
https://doi.org/10.5194/wcd-3-777-2022
© 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-3-777-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
21 Jul 2022
Research article | Highlight paper |
| 21 Jul 2022
| 21 Jul 2022
Trends in the tropospheric general circulation from 1979 to 2022
Adrian J. Simmons
CORRESPONDING AUTHOR
Copernicus Department, European Centre for Medium-Range Weather Forecasts, Shinfield Park, Reading RG2 9AX, UK
Related authors
Masatomo Fujiwara, Jonathon S. Wright, Gloria L. Manney, Lesley J. Gray, James Anstey, Thomas Birner, Sean Davis, Edwin P. Gerber, V. Lynn Harvey, Michaela I. Hegglin, Cameron R. Homeyer, John A. Knox, Kirstin Krüger, Alyn Lambert, Craig S. Long, Patrick Martineau, Andrea Molod, Beatriz M. Monge-Sanz, Michelle L. Santee, Susann Tegtmeier, Simon Chabrillat, David G. H. Tan, David R. Jackson, Saroja Polavarapu, Gilbert P. Compo, Rossana Dragani, Wesley Ebisuzaki, Yayoi Harada, Chiaki Kobayashi, Will McCarty, Kazutoshi Onogi, Steven Pawson, Adrian Simmons, Krzysztof Wargan, Jeffrey S. Whitaker, and Cheng-Zhi Zou
Atmos. Chem. Phys., 17, 1417–1452, https://doi.org/10.5194/acp-17-1417-2017, https://doi.org/10.5194/acp-17-1417-2017, 2017
Short summary
Short summary
We introduce the SPARC Reanalysis Intercomparison Project (S-RIP), review key concepts and elements of atmospheric reanalysis systems, and summarize the technical details of and differences among 11 of these systems. This work supports scientific studies and intercomparisons of reanalysis products by collecting these background materials and technical details into a single reference. We also address several common misunderstandings and points of confusion regarding reanalyses.
Masatomo Fujiwara, Jonathon S. Wright, Gloria L. Manney, Lesley J. Gray, James Anstey, Thomas Birner, Sean Davis, Edwin P. Gerber, V. Lynn Harvey, Michaela I. Hegglin, Cameron R. Homeyer, John A. Knox, Kirstin Krüger, Alyn Lambert, Craig S. Long, Patrick Martineau, Andrea Molod, Beatriz M. Monge-Sanz, Michelle L. Santee, Susann Tegtmeier, Simon Chabrillat, David G. H. Tan, David R. Jackson, Saroja Polavarapu, Gilbert P. Compo, Rossana Dragani, Wesley Ebisuzaki, Yayoi Harada, Chiaki Kobayashi, Will McCarty, Kazutoshi Onogi, Steven Pawson, Adrian Simmons, Krzysztof Wargan, Jeffrey S. Whitaker, and Cheng-Zhi Zou
Atmos. Chem. Phys., 17, 1417–1452, https://doi.org/10.5194/acp-17-1417-2017, https://doi.org/10.5194/acp-17-1417-2017, 2017
Short summary
Short summary
We introduce the SPARC Reanalysis Intercomparison Project (S-RIP), review key concepts and elements of atmospheric reanalysis systems, and summarize the technical details of and differences among 11 of these systems. This work supports scientific studies and intercomparisons of reanalysis products by collecting these background materials and technical details into a single reference. We also address several common misunderstandings and points of confusion regarding reanalyses.
Related subject area
Other aspects of weather and climate dynamics
ClimaMeter: contextualizing extreme weather in a changing climate
Large-ensemble assessment of the Arctic stratospheric polar vortex morphology and disruptions
Elevation-dependent warming: observations, models, and energetic mechanisms
Meeting summary: Exploring cloud dynamics with Cloud Model 1 and 3D visualization – insights from a university modeling workshop
Waviness of the Southern Hemisphere wintertime polar and subtropical jets
The importance of regional sea-ice variability for the coastal climate and near-surface temperature gradients in Northeast Greenland
Decadal variability and trends in extratropical Rossby wave packet amplitude, phase, and phase speed
Stratospheric intrusion depth and its effect on surface cyclogenetic forcing: an idealized potential vorticity (PV) inversion experiment
Supercell convective environments in Spain based on ERA5: hail and non-hail differences
A characterisation of Alpine mesocyclone occurrence
Intraseasonal variability of ocean surface wind waves in the western South Atlantic: the role of cyclones and the Pacific South American pattern
A dynamical adjustment perspective on extreme event attribution
The signature of the tropospheric gravity wave background in observed mesoscale motion
Increasing frequency in off-season tropical cyclones and its relation to climate variability and change
Davide Faranda, Gabriele Messori, Erika Coppola, Tommaso Alberti, Mathieu Vrac, Flavio Pons, Pascal Yiou, Marion Saint Lu, Andreia N. S. Hisi, Patrick Brockmann, Stavros Dafis, Gianmarco Mengaldo, and Robert Vautard
Weather Clim. Dynam., 5, 959–983, https://doi.org/10.5194/wcd-5-959-2024, https://doi.org/10.5194/wcd-5-959-2024, 2024
Short summary
Short summary
We introduce ClimaMeter, a tool offering real-time insights into extreme-weather events. Our tool unveils how climate change and natural variability affect these events, affecting communities worldwide. Our research equips policymakers and the public with essential knowledge, fostering informed decisions and enhancing climate resilience. We analysed two distinct events, showcasing ClimaMeter's global relevance.
Ales Kuchar, Maurice Öhlert, Roland Eichinger, and Christoph Jacobi
Weather Clim. Dynam., 5, 895–912, https://doi.org/10.5194/wcd-5-895-2024, https://doi.org/10.5194/wcd-5-895-2024, 2024
Short summary
Short summary
Exploring the polar vortex's impact on climate, the study evaluates model simulations against the ERA5 reanalysis data. Revelations about model discrepancies in simulating disruptive stratospheric warmings and vortex behavior highlight the need for refined model simulations of past climate. By enhancing our understanding of these dynamics, the research contributes to more reliable climate projections of the polar vortex with the impact on surface climate.
Michael P. Byrne, William R. Boos, and Shineng Hu
Weather Clim. Dynam., 5, 763–777, https://doi.org/10.5194/wcd-5-763-2024, https://doi.org/10.5194/wcd-5-763-2024, 2024
Short summary
Short summary
In this study we investigate why climate change is amplified in mountain regions, a phenomenon known as elevation-dependent warming (EDW). We examine EDW using observations and models and assess the roles of radiative forcing vs. internal variability in driving the historical signal. Using a forcing–feedback framework we also quantify for the first time the processes driving EDW on large scales. Our results have important implications for understanding future climate change in mountain regions.
Lisa Schielicke, Yidan Li, Jerome Schyns, Aaron Sperschneider, Jose Pablo Solano Marchini, and Christoph Peter Gatzen
Weather Clim. Dynam., 5, 703–710, https://doi.org/10.5194/wcd-5-703-2024, https://doi.org/10.5194/wcd-5-703-2024, 2024
Short summary
Short summary
We present course contents and results of a 2-week educational block course with a focus on Cloud Model 1 (CM1) and 3D visualization. Through hands-on experience, students gained skills in setting up and customizing the model and visualizing its output in 3D. The research aimed to bridge the gap between classroom learning and practical applications, fostering a deeper understanding of convective processes and preparing students for future careers in the field.
Jonathan E. Martin and Taylor Norton
Weather Clim. Dynam., 4, 875–886, https://doi.org/10.5194/wcd-4-875-2023, https://doi.org/10.5194/wcd-4-875-2023, 2023
Short summary
Short summary
The polar and subtropical jets are important weather-producing features and influential governors of regional climate. This study considers trends in the waviness of the two jets in Southern Hemisphere winter using three data sets and reveals three important results: (1) the waviness of both jets has increased since about 1960, (2) only the maximum speed of the subtropical jet has increased, and (3) both the polar and subtropical jets have been shifting poleward over the last several decades.
Sonika Shahi, Jakob Abermann, Tiago Silva, Kirsty Langley, Signe Hillerup Larsen, Mikhail Mastepanov, and Wolfgang Schöner
Weather Clim. Dynam., 4, 747–771, https://doi.org/10.5194/wcd-4-747-2023, https://doi.org/10.5194/wcd-4-747-2023, 2023
Short summary
Short summary
This study highlights how the sea ice variability in the Greenland Sea affects the terrestrial climate and the surface mass changes of peripheral glaciers of the Zackenberg region (ZR), Northeast Greenland, combining model output and observations. Our results show that the temporal evolution of sea ice influences the climate anomaly magnitude in the ZR. We also found that the changing temperature and precipitation patterns due to sea ice variability can affect the surface mass of the ice cap.
Georgios Fragkoulidis
Weather Clim. Dynam., 3, 1381–1398, https://doi.org/10.5194/wcd-3-1381-2022, https://doi.org/10.5194/wcd-3-1381-2022, 2022
Short summary
Short summary
Assessing the seasonal distributions of local Rossby wave packet (RWP) amplitude, phase, and phase speed on reanalysis data of the 1979–2019 period reveals that patterns of robust trends emerge and vary substantially between seasons and regions. While an absence of covariance is evident between RWP amplitude and phase speed at decadal scales, the frequency of DJF large-amplitude quasi-stationary RWPs increases in several areas of the N Pacific and N America during 1999–2019.
Michael A. Barnes, Thando Ndarana, Michael Sprenger, and Willem A. Landman
Weather Clim. Dynam., 3, 1291–1309, https://doi.org/10.5194/wcd-3-1291-2022, https://doi.org/10.5194/wcd-3-1291-2022, 2022
Short summary
Short summary
Stratospheric air can intrude into the troposphere and is associated with cyclonic development throughout the atmosphere. Through a highly idealized systematic approach, the effect that different intrusion characteristics have on surface cyclogenetic forcing is investigated. The proximity of stratospheric intrusions to the surface is shown to be the main factor in surface cyclogenetic forcing, whilst its width is an additional contributing factor.
Carlos Calvo-Sancho, Javier Díaz-Fernández, Yago Martín, Pedro Bolgiani, Mariano Sastre, Juan Jesús González-Alemán, Daniel Santos-Muñoz, José Ignacio Farrán, and María Luisa Martín
Weather Clim. Dynam., 3, 1021–1036, https://doi.org/10.5194/wcd-3-1021-2022, https://doi.org/10.5194/wcd-3-1021-2022, 2022
Short summary
Short summary
Supercells are among the most complex and dangerous severe convective storms due to their associated phenomena (lightning, strong winds, large hail, flash floods, or tornadoes). In this survey we study the supercell synoptic configurations and convective environments in Spain using the atmospheric reanalysis ERA5. Supercells are grouped into hail (greater than 5 cm) and non-hail events in order to compare and analyze the two events. The results reveal statistically significant differences.
Monika Feldmann, Urs Germann, Marco Gabella, and Alexis Berne
Weather Clim. Dynam., 2, 1225–1244, https://doi.org/10.5194/wcd-2-1225-2021, https://doi.org/10.5194/wcd-2-1225-2021, 2021
Short summary
Short summary
Mesocyclones are the rotating updraught of supercell thunderstorms that present a particularly hazardous subset of thunderstorms. A first-time characterisation of the spatiotemporal occurrence of mesocyclones in the Alpine region is presented, using 5 years of Swiss operational radar data. We investigate parallels to hailstorms, particularly the influence of large-scale flow, daily cycles and terrain. Improving understanding of mesocyclones is valuable for risk assessment and warning purposes.
Dalton K. Sasaki, Carolina B. Gramcianinov, Belmiro Castro, and Marcelo Dottori
Weather Clim. Dynam., 2, 1149–1166, https://doi.org/10.5194/wcd-2-1149-2021, https://doi.org/10.5194/wcd-2-1149-2021, 2021
Short summary
Short summary
Extratropical cyclones are relevant in the western South Atlantic and influence the climate of ocean surface wave. Propagating atmospheric features from the South Pacific to the South Atlantic are relevant to the cyclones and waves, and its intensified westerlies lead to more cyclones and, as a consequence, to higher wave heights. The opposite happens with its weakening. These features are similar to the so-called Pacific South American patterns and present periods between 30 and 180 d.
Laurent Terray
Weather Clim. Dynam., 2, 971–989, https://doi.org/10.5194/wcd-2-971-2021, https://doi.org/10.5194/wcd-2-971-2021, 2021
Short summary
Short summary
Attribution of the causes of extreme temperature events has become active research due to the wide-ranging impacts of recent heat waves and cold spells. Here we show that a purely observational approach based on atmospheric circulation analogues and resampling provides a robust quantification of the various dynamic and thermodynamic contributions to specific extreme temperature events. The approach can easily be integrated in the toolbox of any real-time extreme event attribution system.
Claudia Christine Stephan and Alexis Mariaccia
Weather Clim. Dynam., 2, 359–372, https://doi.org/10.5194/wcd-2-359-2021, https://doi.org/10.5194/wcd-2-359-2021, 2021
Short summary
Short summary
Vertical motion on horizontal scales of a few hundred kilometers can influence cloud properties. This motion is difficult to measure directly but can be inferred from the area-averaged mass divergence. The latter can be derived from horizontal wind measurements at the area’s perimeter. This study derives vertical properties of area-averaged divergence from an extensive network of atmospheric soundings and proposes an explanation for the variation of divergence magnitudes with area size.
José J. Hernández Ayala and Rafael Méndez-Tejeda
Weather Clim. Dynam., 1, 745–757, https://doi.org/10.5194/wcd-1-745-2020, https://doi.org/10.5194/wcd-1-745-2020, 2020
Short summary
Short summary
This study focused on exploring if off-season tropical cyclones, those that develop outside of the peak months, have been increasing over time in the Atlantic Ocean and Pacific Ocean basins and if that higher frequency could be explained by climate variability or change. We found that off-season tropical cyclones are exhibiting an increase in total numbers by decade in the North Atlantic and East Pacific ocean basins and that climate change explained much of the increasing trends over time.
Cited articles
Bell, B., Hersbach, H., Simmons, A., Berrisford, P., Dahlgren, P., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Radu, R., Schepers, D., Soci, C., Villaume, S., Bidlot, J.-R., Haimberger, L., Woollen, J., Buontempo, C., and Thépaut, J.-N.: The ERA5 global reanalysis:
Preliminary extension to 1950, Q. J. Roy. Meteor. Soc., 147, 4186–4227,
https://doi.org/10.1002/qj.4174, 2021.
Berrisford, P., Dee, D., Poli, P., Brugge, R., Fielding, K., Fuentes, M.,
Kållberg, P., Kobayashi, S., Uppala, S., and Simmons, A.: The
ERA-Interim archive, Version 2.0. ERA Report Series no. 1, 23 pp, https://www.ecmwf.int/en/elibrary/8174-era-interim-archive-version-20 (last access: 15 July 2022), 2011.
Byrne, N. J., Shepherd, T. G., Woollings, T., and Plumb, R. A.:
Nonstationarity in southern hemisphere climate variability associated with
the seasonal breakdown of the stratospheric polar vortex, J. Climate, 30,
7125–7139, https://doi.org/10.1175/JCLI-D-17-0097.1, 2017.
Cheng, L., Foster, G., Hausfather, Z., Trenberth. K. E., and Abraham, J.:
Improved quantification of the rate of ocean warming, J. Climate, 35, 4827–4840, https://doi.org/10.1175/JCLI-D-21-0895.1,
2022.
Chung, E.-S., Timmermann, A., Soden, B. J., Ha, K.-J., Shi, L., and John, V.
O.: Reconciling opposing Walker circulation trends in observations and model
projections, Nat. Clim. Chang., 9, 405–412,
https://doi.org/10.1038/s41558-019-0446-4, 2019.
de Boisséson, E., Balmaseda, M. A., Abdalla, S., Källén, E., and
Janssen, P. A. E. M.: How robust is the recent strengthening of the Tropical
Pacific trade winds?, Geophys. Res. Lett., 41, 4398–4405,
https://doi.org/10.1002/2014GL060257, 2014.
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.
Dong, B., Sutton, R. T., Shaffrey, L., and Harvey, B.: Recent decadal
weakening of the summer Eurasian westerly jet attributable to anthropogenic
aerosol emissions, Nat. Commun., 13, 1148,
https://doi.org/10.1038/s41467-022-28816-5, 2022.
Francis, J. A. and Vavrus, S. J.: Evidence linking Arctic amplification to
extreme weather in mid-latitudes, Geophys. Res. Lett., 39, L06801,
https://doi.org/10.1029/2012GL051000, 2012.
Gelaro, R., McCarty, W., Suárez, M. J., Todling, R., Molod, A., Takacs,
L., Randles, C. A., Darmenov, A., Bosilovich, M. G., Reichle, R., Wargan,
K., Coy, L., Cullather, R., Draper, C., Akella, S., Buchard, V., Conaty, A.,
da Silva, A. M., Gu, W., Kim, G., Koster, R., Lucchesi, R., Merkova, D.,
Nielsen, J. E., Partyka, G., Pawson, S., Putman, W., Rienecker, M.,
Schubert, S. D., Sienkiewicz, M., and Zhao, B.: The Modern-Era Retrospective
Analysis for Research and Applications, Version 2 (MERRA-2), J. Climate, 30,
5419–5454, https://doi.org/10.1175/JCLI-D-16-0758.1, 2017.
Gulev, S. K., Thorne, P. W., Ahn, J., Dentener, F. J., Domingues, C. M.,
Gerland, S., Gong, D., Kaufman, D. S., Nnamchi, H. C., Quaas, J., Rivera, J.
A., Sathyendranath, S., Smith, S. L., Trewin, B., von Shuckmann, K., and Vose, R. S.: Changing State of the Climate System, in: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth
Assessment Report of the Intergovernmental Panel on Climate Change, edited
by: Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C.,
Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M.,
Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield,
T., Yelekçi, O., Yu, R., and Zhou, B., Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA, 287–422,
https://www.ipcc.ch/report/ar6/wg1/ (last access: 15 July 2022), 2021.
Haimberger, L.: Homogenization of radiosonde temperature time series using
innovation statistics, J. Climate, 20, 1377–1403,
https://doi.org/10.1175/JCLI4050.1, 2007.
Haimberger, L., Tavolato, C., and Sperka, S.: Toward elimination of the warm
bias in historic radiosonde temperature records: Some new results from a
comprehensive intercomparison of upper-air data, J. Climate, 21, 4587–4606,
https://doi.org/10.1175/2008JCLI1929.1, 2008.
Haimberger, L., Tavolato, C., and Sperka, S.: Homogenization of the global
radiosonde temperature dataset through combined comparison with reanalysis
background series and neighboring stations, J. Climate, 25, 8108–8131,
https://doi.org/10.1175/JCLI-D-11-00668.1, 2012.
Harrington, L. J.: Temperature emergence at decision-relevant scales,
Environ. Res. Lett., 16, 094018, https://doi.org/10.1088/1748-9326/ac19dc, 2021.
Hawkins, E., Frame, D., Harrington, L. J., Joshi, M., King, A., Rojas, M.,
and Sutton, R.: Observed emergence of the climate change signal: from the
familiar to the unknown, Geophys. Res. Lett., 47, e2019GL086259,
https://doi.org/10.1029/2019GL086259, 2020.
Hersbach H., Peubey, C., Simmons, A., Berrisford, P., Poli, P., and Dee, D.:
ERA-20CM: a twentieth-century atmospheric model ensemble, Q. J. Roy. Meteor. Soc., 141, 2350–2375, https://doi.org/10.1002/qj.2528, 2015.
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., Hólm, E., Janisková, M.,
Keeley, S., Laloyaux, P., Lopez, P., 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.
Hoskins, B. J. and Hodges, K. I.: The annual cycle of northern hemisphere
storm tracks, Part I: Seasons. J. Climate, 32, 1743–1760,
https://doi.org/10.1175/JCLI-D-17-0870.1, 2019a.
Hoskins, B. J. and Hodges, K. I.: The annual cycle of northern hemisphere
storm tracks, Part II: Regional detail, J. Climate, 32, 1761–1775,
https://doi.org/10.1175/JCLI-D-17-0871.1, 2019b.
Hoskins, B. J. and Woollings, T.: Persistent extratropical regimes and
climate extremes, Curr. Clim. Change Rep., 1, 115–124, https://doi.org/10.1007/s40641-015-0020-8, 2015.
Huang, S., Wang, B., and Wen, Z.: Dramatic weakening of the tropical
easterly jet projected by CMIP6 Models, J. Climate, 33, 8439–8455,
https://doi.org/10.1175/jcli-d-19-1002.1, 2020.
IPCC: Climate Change 2021: The Physical Science Basis. Contribution of
Working Group I to the Sixth Assessment Report of the Intergovernmental
Panel on Climate Change, edited by: Masson-Delmotte, V., Zhai, P., Pirani,
A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb,
L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R.,
Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R., and Zhou, B.,
Cambridge University Press, https://www.ipcc.ch/report/ar6/wg1/ (last access: 15 July 2022), in press, 2022.
Keil, P., Mauritsen, T., Jungclaus, J., Hedemann, C., Olonscheck, D., and
Ghosh, R.: Multiple drivers of the North Atlantic warming hole, Nat. Clim.
Chang., 10, 667–671, https://doi.org/10.1038/s41558-020-0819-8, 2020.
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., 93, 5–48, https://doi.org/10.2151/jmsj.2015-001, 2015.
Lenssen, N., Schmidt, G., Hansen, J., Menne, M., Persin, A., Ruedy, R., and
Zyss, D.: Improvements in the GISTEMP uncertainty model, J. Geophys. Res.-Atmos., 124, 6307–6326, https://doi.org/10.1029/2018JD029522, 2019.
Lewis, J. M.: Ooishi's observation. Viewed in the context of jet stream
discovery, B. Am. Meteorol. Soc., 84, 357–370, https://doi.org/10.1175/BAMS-84-3-357, 2003.
Lim, E.-P., Hendon, H. H., and Thompson, D. W. J.: Seasonal evolution of
stratosphere-troposphere coupling in the southern hemisphere and
implications for the predictability of surface climate, J. Geophys. Res.,
123, 12002–12016, https://doi.org/10.1029/2018JD029321, 2018.
Lorenz, E. N.: Available potential energy and the maintenance of the general
circulation, Tellus, 7, 157–167, https://doi.org/10.1111/j.2153-3490.1955.tb01148.x, 1955.
Lorenz, E. N.: The nature and theory of the general circulation of the
atmosphere, World Meteorological Organization, No. 218, TP. 115, 161 pp., https://library.wmo.int/index.php?lvl=notice_display&id=5571#.YtEtPYTMJro
(last access: 15 July 2022), 1967.
Ma, Q., Lembo, V., and Franzke, C. L. E.: The Lorenz energy cycle: trends
and the impact of modes of climate variability, Tellus, 73, 1–15,
https://doi.org/10.1080/16000870.2021.1900033, 2021.
Ma, S. and Zhou, T.: Robust strengthening and westward shift of the tropical
Pacific Walker Circulation during 1979–2012: A comparison of 7 sets of
reanalysis data and 26 CMIP5 models, J. Climate, 29, 3097–3116,
https://doi.org/10.1175/JCLI-D-15-0398.1, 2016.
Manney, G. L. and Hegglin, M. I.: Seasonal and regional variations of
long-term changes in upper-tropospheric jets from reanalyses, J. Climate,
34, 9181–9200, https://doi.org/10.1175/JCLI-D-17-0303.1, 2018.
Manney, G. L., Hegglin, M. I., and Lawrence, Z. D.: Seasonal and regional
signatures of ENSO in upper tropospheric jet characteristics from
reanalyses, J. Climate, 31, 423–448, https://doi.org/10.1175/JCLI-D-20-0947.1, 2021.
Morice, C. P., Kennedy, J. J., Rayner, N. A., Winn, J. P., Hogan, E.,
Killick, R. E., Dunn, R. J. H., Osborn, T. J., Jones, P. D., and Simpson, I.
R.: An updated assessment of near-surface temperature change from 1850: the
HadCRUT5 dataset, J. Geophys. Res.-Atmos., 126, e2019JD032361,
https://doi.org/10.1029/2019JD032361, 2020.
Oudar, T., Cattiaux, J., and Douville, H.: Drivers of the northern
extratropical eddy-driven jet change in CMIP5 and CMIP6 models, Geophys.
Res. Lett., 47, e2019GL086695, https://doi.org/10.1029/2019GL086695, 2020.
Pena-Ortiz, C., Gallego, D., Ribera, P., Ordonez, P., and Alvarez-Castro, M.
D. C.: Observed trends in the global jet stream characteristics during the
second half of the 20th century, J. Geophys. Res.-Atmos., 118, 2702–2713,
https://doi.org/10.1002/jgrd.50305, 2013.
Pikovnik, M., Zaplotnik, Ž., Boljka, L., and Žagar, N.: Metrics of the Hadley circulation strength and associated circulation trends, Weather Clim. Dynam., 3, 625–644, https://doi.org/10.5194/wcd-3-625-2022, 2022.
Santer, B. D., Thorne, P. W., Haimberger, L., Taylor, K. E., Wigley, T. M.
L., Lanzante, J. R., Solomon, S., Free, M., Gleckler, P. J., Jones, P. D.,
Karl, T. R., Klein, S. A., Mears, C., Nychka, D., Schmidt, G. A., Sherwood,
S. C., and Wentz, F. J.: Consistency of modelled and observed temperature
trends in the tropical troposphere, Int. J. Climatol., 28, 1703–1722,
https://doi.org/10.1002/joc.1756, 2008.
Screen, J. A., Bracegirdle, T. J., and Simmonds, I.: Polar climate change as
manifest in atmospheric circulation, Curr. Clim. Change Rep., 4, 383–395,
https://doi.org/10.1007/s40641-018-0111-4, 2018.
Serreze, M. and Barry, R.: Processes and impacts of Arctic amplification: A
research synthesis, Global Planet. Change, 77, 85–96,
https://doi.org/10.1016/j.gloplacha.2011.03.004, 2011.
Shepherd, T. G.: Bringing physical reasoning into statistical practice in
climate-change science, Climatic Change, 169, 2, https://doi.org/10.1007/s10584-021-03226-6, 2021.
Simmonds, I. and Li, M.: Trends and variability in polar sea ice, global
atmospheric circulations, and baroclinicity, Ann. NY Acad. Sci., 1504,
167–186, https://doi.org/10.1111/nyas.14673, 2021.
Simmons, A. J. and Hoskins, B. J.: The life cycles of some nonlinear
baroclinic waves, J. Atmos. Sci., 35, 414–432, https://doi.org/10.1175/1520-0469(1978)035<0414:TLCOSN>2.0.CO;2, 1978.
Simmons, A. J., Jones, P. D., da Costa Bechtold, V., Beljaars, A. C. M.,
Kållberg, P. W., Saarinen, S., Uppala, S. M., Viterbo, P., and Wedi, N.:
Comparison of trends and low-frequency variability in CRU, ERA-40 and
NCEP/NCAR analyses of surface air temperature, J. Geophys. Res., 109,
D24115, https://doi.org/10.1029/2004JD005306, 2004.
Simmons, A. J., Berrisford, P., Dee, D. P., Hersbach, H., Hirahara, S., and
Thépaut, J.-N.: A reassessment of temperature variations and trends from
global reanalyses and monthly surface climatological datasets, Q. J.
Roy. Meteor. Soc., 143, 101–119, https://doi.org/10.1002/qj.2949, 2017.
Simmons, A. J., Soci, C., Nicolas, J., Bell, W., Berrisford, P., Dragani,
R., Flemming, J., Haimberger, L., Healy, S., Hersbach, H., Horányi, A.,
Inness, A., Muñoz-Sabater, J. Radu, R., and Schepers, D.: Global
stratospheric temperature bias and other stratospheric aspects of ERA5 and
ERA5.1, ECMWF Tech Memo no. 859, 38 pp., https://doi.org/10.21957/rcxqfmg0, 2020.
Simmons, A. J., Hersbach, H., Muñoz-Sabater, J., Nicolas, J., Vamborg,
F., Berrisford, P., de Rosnay, P., Willett, K., and Woollen, J.: Low
frequency variability and trends in surface air temperature and humidity
from ERA5 and other datasets, ECMWF Tech Memo no. 881, 97 pp.,
https://doi.org/10.21957/ly5vbtbfd, 2021.
Smith, D. M., Eade, R., Andrews, M. B., Ayres, H., Clark, A., Chripko, S.,
Deser, C., Dunstone, N. J., García-Serrano, J., Gastineau, G., Graff,
L. S., Hardiman, S. C., He, B., Hermanson, L., Jung, T., Knight, J., Levine,
X., Magnusdottir, G., Manzini, E., Matei, D., Mori, M., Msadek, R., Ortega,
P., Peings, Y., Scaife, A. A., Screen, J. A., Seabrook, M., Semmler, T.,
Sigmond, M., Streffing, J., Sun, L., and Walsh, A.: Robust but weak winter
atmospheric circulation response to future Arctic sea ice loss, Nat. Commun.,
13, 727, https://doi.org/10.1038/s41467-022-28283-y, 2022.
Thompson, C. F. and Schultz, D. M.: The release of inertial instability
near an idealized zonal jet. Geophys. Res. Lett., 48, e2021GL092649,
https://doi.org/10.1029/2021GL092649, 2021.
Thorncroft, C. D., Hoskins, B. J., and McIntyre, M. E.: Two paradigms of
baroclinic-wave life-cycle behaviour, Q. J. Roy. Meteor. Soc., 119,
17–55, https://doi.org/10.1002/qj.49711950903, 1993.
Trewin, B.: A daily homogenized temperature data set for Australia, Int.
Climatol., 33, 1510–1529, https://doi.org/10.1002/joc.3530, 2013.
Wentz, F. J.: A well-calibrated ocean algorithm for SSM/I, J. Geophys. Res.,
102, 8703–8718, https://doi.org/10.1029/96JC01751, 1997.
Wentz, F. J. and Francis, E. A.: Nimbus-7 SMMR Ocean Products, 1979–1984,
Remote Sensing Systems Technical Report 033192, Remote Sensing Systems, Santa Rosa, CA 95404, 36 pp., https://www.remss.com (last access: 16 July 2022), 1992.
Wilks, D. S.: “The stippling shows statistically significant grid points”:
How research results are routinely overstated and overinterpreted, and what
to do about it, B. Am. Meteorol. Soc., 97, 2263–2273,
https://doi.org/10.1175/BAMS-D-15-00267.1, 2016.
Wu, M., Zhou, T., Li, C., Li, H., Chen, X., Wu, B., Zhang, W., and Zhang,
L.: A very likely weakening of Pacific Walker Circulation in constrained
near-future projections, Nat. Commun., 12, 6502,
https://doi.org/10.1038/s41467-021-26693-y, 2021.
Žagar, N., Zaplotnik, Ž., and Karami, K.: Atmospheric subseasonal
variability and circulation regimes: spectra, trends, and uncertainties, J.
Climate, 33, 9375–9390, https://doi.org/10.1175/JCLI-D-20-0225.1, 2020.
Zappa, G. and Shepherd, T. G.: Storylines of atmospheric circulation change
for European regional climate impact assessment, J. Climate, 30, 6561–6577,
https://doi.org/10.1175/JCLI-D-16-0807.1, 2017.
Executive editor
Analysing and understanding potential trends in the atmospheric circulation over the last decades is an important aspect of atmospheric dynamics. In this article, Adrian Simmons performed a very thorough global trend analysis, with a focus on near-tropopause winds, based on ERA5 reanalyses. The paper provides an excellent overview and emphasises important regional and seasonal differences. It is shown that despite Arctic amplification, the upper-level westerlies mainly strengthened at northern middle latitudes. Focusing on jet-stream wind maxima, it is found that they increased over the North Atlantic. These results and the detailed global trend overview will be useful for the community to further investigate the underlying physical processes that led to these trends in the last decades.
Analysing and understanding potential trends in the atmospheric circulation over the last...
Short summary
This study of changes in temperature and wind since 1979 met its twin aims of (i) increasing confidence in some findings of the latest IPCC assessment and (ii) identifying changes that had received little or no previous attention. It reports a small overall intensification and shift in position of the North Atlantic jet stream and associated storms, and a strengthening of tropical upper-level easterlies. Increases in low-level winds over tropical and southern hemispheric oceans are confirmed.
This study of changes in temperature and wind since 1979 met its twin aims of (i) increasing...
