Preprints
https://doi.org/10.5194/egusphere-2026-3630
https://doi.org/10.5194/egusphere-2026-3630
09 Jul 2026
 | 09 Jul 2026
Status: this preprint is open for discussion and under review for Earth System Dynamics (ESD).

Anthropogenic control on solar-induced hydro-meteorological summer extremes

Tobias Spiegl, Norel Rimbu, Franziska Kappenberger, Xiaojie Hao, Wenjuan Huo, Stephan Thober, Ulrike Langematz, and Gerrit Lohmann

Abstract. Solar variability leaves detectable, climate state–dependent imprints on summer hydro-meteorological extremes. We show that centennial-scale solar minima, including the Maunder and Dalton minima, enhanced summer flooding and heavy precipitation from Western to Southeastern Europe under pre-industrial conditions, by combining a chemistry–climate model with palaeoclimate reconstructions and proxy records. We identify the physical mechanism linking reduced solar irradiance, stratospheric ozone changes, and sea-ice persistence to modified meridional temperature and pressure gradients and a southward shift of the European storm track. Model–data convergence supports this mechanism and its intra-seasonal amplification toward late summer. In a high-emissions future climate, the loss of summer sea ice and a weaker, northward-shifted storm track suppress this pathway, diminishing the sensitivity of European summer extremes to identical solar perturbations. Our results highlight the critical role of background climate state for interpreting solar fingerprints in past records and assessing future risks.

Competing interests: G.L. is a member of the editorial board of Earth System Dynamics. All other authors do not have any potential conflicts of interest.

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
Tobias Spiegl, Norel Rimbu, Franziska Kappenberger, Xiaojie Hao, Wenjuan Huo, Stephan Thober, Ulrike Langematz, and Gerrit Lohmann

Status: open (until 20 Aug 2026)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
Tobias Spiegl, Norel Rimbu, Franziska Kappenberger, Xiaojie Hao, Wenjuan Huo, Stephan Thober, Ulrike Langematz, and Gerrit Lohmann
Tobias Spiegl, Norel Rimbu, Franziska Kappenberger, Xiaojie Hao, Wenjuan Huo, Stephan Thober, Ulrike Langematz, and Gerrit Lohmann
Metrics will be available soon.
Latest update: 09 Jul 2026
Download
Short summary
Natural solar signals are not fixed in time. During past centennial-scale solar minima, reduced solar activity promoted summer heavy precipitation through coupled changes in ozone, sea ice and storm tracks. In a warmer future climate, this pathway weakens, showing that anthropogenic warming can reshape how natural forcings translate into regional weather extremes.
Share