Preprints
https://doi.org/10.5194/egusphere-2025-3379
https://doi.org/10.5194/egusphere-2025-3379
29 Jul 2025
 | 29 Jul 2025
Status: this preprint is open for discussion and under review for Earth System Dynamics (ESD).

Dynamical System Metrics and Weather Regimes explain the seasonally-varying link between European Heatwaves and the large-scale atmospheric circulation

Ines Dillerup, Alexander Lemburg, Sebastian Buschow, and Joaquim G. Pinto

Abstract. Global warming is projected to increase the frequency and intensity of heatwaves in the extended summer period. To better predict heat extremes, it is important to explore the seasonal variations in their drivers. Therefore, we analyze heatwaves in Central Europe using ERA5 reanalysis data over the historical period (1950–2023) for the extended summer months (May–September). We quantify atmospheric persistence, and the link between near-surface temperatures and large-scale atmospheric circulation patterns using dynamical system metrics. This approach is further contextualized by the consideration of weather regimes, which represent the low-frequency variability of the atmosphere over the North Atlantic and Europe.

Our results show a maximum in atmospheric persistence in July and August, associated with higher occurrence of Scandinavian Blocking, and relative minima in spring and autumn. The relationship between the large-scale atmospheric circulation and near-surface temperatures exhibits similar seasonal characteristics. For heatwave days, we find a statistically significant anomalous strong link between large-scale atmospheric circulation and surface temperatures from June to September. This relationship is generally not attributable to the occurrence of specific weather regimes. However, heatwaves in July and August are associated with higher atmospheric persistence due to an enhanced frequency of the persistent Scandinavian and European blocking weather regimes. Beyond atmospheric circulation, additional physical drivers of daily maximum temperature during heatwaves are analyzed: While surface net solar radiation shows a particularly strong link in June and July, soil moisture exhibits an anomalously high link in July and August. These findings highlight the critical role of intra-seasonal variations in shaping heatwave dynamics.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Share
Ines Dillerup, Alexander Lemburg, Sebastian Buschow, and Joaquim G. Pinto

Status: open (until 04 Oct 2025)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2025-3379', Anonymous Referee #1, 09 Sep 2025 reply
Ines Dillerup, Alexander Lemburg, Sebastian Buschow, and Joaquim G. Pinto
Ines Dillerup, Alexander Lemburg, Sebastian Buschow, and Joaquim G. Pinto

Viewed

Total article views: 394 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
337 47 10 394 25 22
  • HTML: 337
  • PDF: 47
  • XML: 10
  • Total: 394
  • BibTeX: 25
  • EndNote: 22
Views and downloads (calculated since 29 Jul 2025)
Cumulative views and downloads (calculated since 29 Jul 2025)

Viewed (geographical distribution)

Total article views: 393 (including HTML, PDF, and XML) Thereof 393 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 09 Sep 2025
Download
Short summary
We analyze the duration of large-scale weather patterns and their link to near-surface temperatures during heatwaves in Central Europe for 1950–2023. Compared to non-heatwave days, a stronger link between them is found on heatwave days from May to September. We relate our results to typical long-lasting weather patterns known as weather regimes. In July and August, weather patterns last longer as west winds are often blocked by Scandinavian and European blocking regimes, inducing hot extremes.
Share